A kept when or else-less chain gives an Option, get is a checked lookup, and .fln has if let and elif let.
This commit is contained in:
commit
322a675f1b
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TODO.org
20
TODO.org
@ -16,15 +16,17 @@ inference like a number literal: u8 or i32 where typed code wants a number (a li
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above 127 is refused as a u8), =char= otherwise; a =char= crossing into dyn stays a char.
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Rules out the fork where =f(\a)= printed =\a= and =let c = \a= then =f(c)= printed 97.
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Waits on the dyn char lane and the literal inference lane.
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** NEXT if let
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Decided 2026-09-26 (126), Rust's spelling: =if let Some(g) = left= plus a block tests
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the pattern and binds =g= in that block only; =elif=/=else= follow as for =if=. Any
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=match= pattern may stand where =Some(g)= is. Reads to a two-arm =match=.
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** NEXT when as a value, and get as a checked lookup
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Decided 2026-09-26 (125): a =when= whose value is used gives =Option(T)=, =Some= of its
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body when the test holds and =None= otherwise; as a statement it is unchanged.
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=get(xs, i, …)= on an array, slice or Vec gives =Option(T)= instead of trapping on an
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index out of range (negative included), one index per dimension. Both typed and dyn.
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** DONE if let
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CLOSED: [2026-09-26]
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=(if-let [P v] then else)= in paren syntax; an elif chain is the else. With no else it
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is a statement unless kept, when it is an Option as =when= is. Rules out a plain name or
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=_= as the pattern (use =let=).
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** DONE when as a value, and get as a checked lookup
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CLOSED: [2026-09-26]
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Every one-armed =if= (and a =cond= with no =:else=) is a =when=; kept — a =let= value, a
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call's argument, a lambda's return — it is =Option(T)=, nested over an Option body
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(Rust's =bool::then=), and body-or-nil where a dyn is wanted. A =_=-inferred return's
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last form is not kept. =get= over dyn text or vec is nil when out of range; =.field= still traps.
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** NEXT str and String
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Decided 2026-09-25: the typed read-only text is =str= (the rename from =string= is
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@ -103,7 +103,7 @@ fine here. Brackets and strings are still paired."
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;; `header_follow' in lib/indent_reader.ml: the words a statement starts with.
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(defconst flan-fln--header-words
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'("fn" "fn-" "def" "once" "const" "struct" "union" "data" "enum" "import"
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"if" "elif" "else" "while" "until" "for" "match" "let" "return" "break"
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"if" "when" "elif" "else" "while" "until" "for" "match" "let" "return" "break"
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"continue" "defer" "handler-case" "handler-bind" "restart-case" "on"
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"restart" "quote" "macro" "type" "class" "generic" "multi" "method"))
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@ -112,7 +112,7 @@ fine here. Brackets and strings are still paired."
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;; when it is the one-line `fn f(x) = e'; `if' does not when it is the one-line
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;; `if c then a else b'.
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(defconst flan-fln--opener-words
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'("fn" "fn-" "struct" "union" "data" "enum" "if" "elif" "else" "while"
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'("fn" "fn-" "struct" "union" "data" "enum" "if" "when" "elif" "else" "while"
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"until" "for" "match" "defer" "handler-case" "handler-bind"
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"restart-case" "on" "restart" "quote" "macro" "class" "multi" "method"))
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@ -410,7 +410,7 @@ and a call ending in `:'."
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(save-excursion
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(goto-char v)
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(or (looking-at "\\(?:match\\|handler-case\\|handler-bind\\|restart-case\\)\\(?:[ \t]\\|$\\)")
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(and (looking-at "if[ \t]") (not (flan-fln--then l)))
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(and (looking-at "\\(?:if\\|when\\)[ \t]") (not (flan-fln--then l)))
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(flan-fln--lambda-header-p v end))))))
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;;; Statements
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@ -1308,7 +1308,7 @@ Before it at the same level, else out to the line that owns this block."
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(not (save-excursion
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(goto-char w-end)
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(looking-at "[ \t]+[^][ \t\n(){},;\":]+("))))
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((member w '("if" "elif")) (not (flan-fln--then start)))
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((member w '("if" "when" "elif")) (not (flan-fln--then start)))
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(t t)))))
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;; `let r = match n', `x = if c', `fn f(x) = match x', a lambda
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;; header: the value goes on under the line.
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@ -1877,6 +1877,9 @@ lambda or a `Fn(...)' type, and not after a match arm's."
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;; The words inside a line: `for i in range(n)', `if c then a else b', a
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;; `where' constraint.
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("[ \t]\\(then\\|else\\|in\\|where\\)[ \t]" 1 font-lock-keyword-face)
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;; `if let Some(g) = x', and a value's `if' or `when', `x = when c then a'.
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("\\_<if[ \t]+\\(let\\)[ \t]" 1 font-lock-keyword-face)
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("[ \t=(,]\\(if\\|when\\)[ \t]" 1 font-lock-keyword-face)
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;; The operator words.
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("\\_<\\(and\\|or\\|not\\)\\_>" 1 font-lock-keyword-face)
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(,(concat "\\_<" (regexp-opt flan--constants t) "\\_>")
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@ -128,7 +128,7 @@
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"Forms that introduce a top-level name.")
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(defconst flan--special
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'("quote" "do" "let" "if" "when" "cond" "and" "or"
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'("quote" "do" "let" "if" "if-let" "when" "cond" "and" "or"
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"while" "until" "break" "continue" "return" "set"
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"array" "array-fill" "array-gen" "the" "match" "fn" "dotimes" "loop" "recur"
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"defer" "some" "try" "signal" "error"
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@ -584,6 +584,7 @@ For `syntax-propertize-function'."
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("handler-case" . 1)
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;; Test first, body after.
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("if" . 1)
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("if-let" . 1)
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("when" . 1)
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("unless" . 1)
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("while" . 1)
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@ -907,6 +907,20 @@ defconst(k, 3)
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(test-flan-fln--tabs "let colors =\n|" 1) 2)
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(test-flan-fln--is "but not after a one-line fn"
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(test-flan-fln--tabs "fn f() -> i32 = 1\n|" 1) 0)
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(test-flan-fln--is "after if let, one level deeper"
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(test-flan-fln--tabs "fn f() -> ()\n if let Some(g) = o\n|" 1) 4)
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(test-flan-fln--is "and after a when with a block"
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(test-flan-fln--tabs "fn f() -> ()\n when a > 1\n|" 1) 4)
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(test-flan-fln--is "but not after a one-line when"
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(test-flan-fln--tabs "fn f() -> ()\n when a then b()\n|" 1) 2)
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(test-flan-fln--in "fn f() -> ()\n if let Some(g) = o\n g\n let w = when a then 1\n when b\n c()\n"
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(font-lock-ensure)
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(let ((face (lambda (needle)
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(save-excursion (goto-char (point-min)) (search-forward needle)
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(get-text-property (match-beginning 0) 'face)))))
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(test-flan-fln--is "if let's let is a keyword" (funcall face "let Some") 'font-lock-keyword-face)
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(test-flan-fln--is "a value's when is a keyword" (funcall face "when a") 'font-lock-keyword-face)
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(test-flan-fln--is "and so is a statement's" (funcall face "when b") 'font-lock-keyword-face)))
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(test-flan-fln--is "else goes to its if's column, whatever the depth"
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(test-flan-fln--tabs "if a\n if b\n c\n |else" 1) 2)
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(test-flan-fln--is "and a second TAB to the outer if's"
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@ -79,6 +79,10 @@ and expr_kind =
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| Field of expr * string (* (.pos c) — auto-derefs one level *)
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| Call of expr * expr list
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| Match of expr * arm list
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(* (if-let [(Some g) left] then else) — [if let Some(g) = left] in .fln.
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A two-arm [match]: the arm is the pattern with [then] as its body, and
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the else is the [_] arm. With no else it is a statement. *)
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| IfLet of expr * arm * expr option
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| Struct of string * (string * expr) list (* (Cursor {.src s}) *)
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(* {.src s .pos 0} with no type written in front of it. The fields alone do
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not name a type, so this node carries no name and is only checkable where
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@ -465,6 +469,7 @@ let map_children f (e : expr) : expr =
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| Field (x, n) -> Field (ex x, n)
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| Call (fn, args) -> Call (ex fn, List.map ex args)
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| Match (s, arms) -> Match (ex s, List.map arm arms)
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| IfLet (s, a, e) -> IfLet (ex s, arm a, Option.map ex e)
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| Struct (n, fs) -> Struct (n, List.map (fun (n, v) -> (n, ex v)) fs)
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| Bare fs -> Bare (List.map (fun (n, v) -> (n, ex v)) fs)
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| MapLit (tag, kvs) -> MapLit (tag, List.map (fun (k, v) -> (ex k, ex v)) kvs)
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@ -538,6 +543,8 @@ and step_expr fn (e : expr) : expr =
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| Dotimes (l, n, b, es) -> { e with e = Dotimes (l, n, b, step_body fn es) }
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| Match (sc, arms) ->
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{ e with e = Match (sc, List.map (fun a -> { a with body = step_body fn a.body }) arms) }
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| IfLet (sc, a, b) ->
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{ e with e = IfLet (sc, { a with body = step_body fn a.body }, Option.map branch b) }
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| _ -> e
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let instrument_step ?(fn = "step-point") (ds : decl list) : decl list option =
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601
lib/check.ml
601
lib/check.ml
@ -944,6 +944,17 @@ type ctx = {
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and a [match] arm. Everything else is therefore non-tail by construction,
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and no walk has to enumerate the cases that are not. *)
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mutable tail : bool;
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(* True where this form's value is kept: a [let] binding's value, and what
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a block's last form, an [if]'s arms and a [match]'s arms inherit from
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the form they stand in. Read and withdrawn at the top of [check] as
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[tail] is. Only a one-armed [if] ([when]) asks: used, it answers an
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Option; not, it is a statement. [want] alone cannot say, since a
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statement and an unannotated [let] value both arrive with none. *)
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mutable used : bool;
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(* The arguments of the call being checked: each is kept, whatever the
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callee wants of it, so a [when] written as an operand answers its Option
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there rather than a Unit the other operands are then blamed against. *)
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mutable kept : Ast.expr list;
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(* True inside a [defer]'s forms. A defer is the cleanup a transfer runs on
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its way out (§5), so a transfer *starting* there has no answer: this
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function's defers are already half run and the first transfer's target is
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@ -5132,7 +5143,7 @@ let with_recovery env ~on f =
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let invented_ctx env ret =
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{ env; ret; lits = None; slots = 0; slot_tys = []; slot_names = []; scope = [];
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defers = []; defer_slot = None; outer = []; outer_what = None; caught = []; place_ok = false; envslot = None; parent = None; in_frames = None; loops = []; tail = false;
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defers = []; defer_slot = None; outer = []; outer_what = None; caught = []; place_ok = false; envslot = None; parent = None; in_frames = None; loops = []; tail = false; used = false; kept = [];
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in_defer = false; defer_ok = false; defer_block = "a nested form";
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owner = "<none>" }
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@ -5787,7 +5798,8 @@ let truthy_depth = ref 0
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it — the square of a refused or/and chain's length. *)
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let if_failed :
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(Loc.t,
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Ast.expr * ((string * binding) list * Types.t) * Types.t option * Loc.diag)
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Ast.expr * ((string * binding) list * Types.t) * (Types.t option * bool)
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* Loc.diag)
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Hashtbl.t =
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Hashtbl.create 16
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let if_depth = ref 0
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@ -6016,6 +6028,8 @@ and check_value ctx ?want (e : Ast.expr) : Tast.expr =
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it unless the arm below hands it on deliberately. *)
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let tail = ctx.tail in
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ctx.tail <- false;
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let used = ctx.used || List.memq e ctx.kept in
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ctx.used <- false;
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match e.Ast.e with
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(* A negative literal in a generic body, at an instantiation that made it
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unsigned. The cast the ordinary refusal names would be wrong at every
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@ -6239,13 +6253,13 @@ and check_value ctx ?want (e : Ast.expr) : Tast.expr =
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in
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check ctx ?want { e with Ast.e = Ast.Int n }
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| Ast.Var name -> var ctx loc ~want name
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| Ast.Do body -> ctx.tail <- tail; block ctx ?want loc body
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| Ast.Do body -> ctx.tail <- tail; ctx.used <- used; block ctx ?want loc body
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(* [defer_ok] rides through: a [let] at the top level of a function body has
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exactly the function's extent, and so does a [let] nested inside one.
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[tail] rides through for the same shape of reason: a [recur] written as
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the last form of a [let] inside a loop body is in the loop's tail. *)
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| Ast.Let (bs, body) -> check_let ctx ~tail ?want ~defer_ok loc bs body
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| Ast.If (c, t, e') -> check_if ctx ~tail ?want loc c t e'
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| Ast.Let (bs, body) -> check_let ctx ~tail ~used ?want ~defer_ok loc bs body
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| Ast.If (c, t, e') -> check_if ctx ~tail ~used ?want loc c t e'
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| Ast.While (label, c, body) ->
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(* The condition is part of the loop even though it is written outside the
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braces — emit puts it in the header block, so it is re-evaluated at the
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@ -6448,7 +6462,9 @@ and check_value ctx ?want (e : Ast.expr) : Tast.expr =
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| Ast.ArrayFill (dims, v) -> check_array_fill ctx ~want loc dims v
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| Ast.ArrayGen (dims, f) -> check_array_gen ctx ~want loc dims f
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| Ast.The (t, v) -> check_the ctx ~want loc t v
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| Ast.Match (scrutinee, arms) -> check_match ctx ~tail ?want loc scrutinee arms
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| Ast.Match (scrutinee, arms) -> check_match ctx ~tail ~used ?want loc scrutinee arms
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| Ast.IfLet (scrutinee, arm, els) ->
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check_if_let ctx ~tail ~used ?want loc scrutinee arm els
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(* Constant integer arithmetic where a type variable is wanted is folded to
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the literal it computes first, so [(+ x (+ 1 2))] is admitted wherever
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[(+ x 3)] is. The instantiation re-checks the form unfolded, at a concrete
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@ -6457,7 +6473,15 @@ and check_value ctx ?want (e : Ast.expr) : Tast.expr =
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when (match want with Some (Types.Var _) -> true | _ -> false)
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&& literal_arith e <> None ->
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int_literal loc ~want ~preds:ctx.env.tvpreds (Option.get (literal_arith e))
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| Ast.Call (head, args) -> check_call ctx ~want loc head args
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| Ast.Call (head, args) ->
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let outer = ctx.kept in
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(* A with-allocator's arguments after the first are a body, run in
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order, and not values. *)
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(match head.Ast.e with
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| Ast.Var ("with-allocator" | "builtin/with-allocator") -> ctx.kept <- []
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| _ -> ctx.kept <- args);
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Fun.protect ~finally:(fun () -> ctx.kept <- outer)
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(fun () -> check_call ctx ~want loc head args)
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| Ast.Unwrap (Ast.Usome, v) ->
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(* Unwrap Some, else early-return None from the enclosing function, so the
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enclosing function must itself return an Option (plan.org). *)
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@ -6917,20 +6941,24 @@ and block ctx ?want ?(defer_ok = false) loc body =
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match body with
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(* Withdrawn here too. An empty body has no last form to be the tail, so
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leaving the permission set would hand it to whatever is checked next. *)
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| [] -> ctx.tail <- false; expect ctx loc ~want (unit_at loc)
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| [] -> ctx.tail <- false; ctx.used <- false; expect ctx loc ~want (unit_at loc)
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| _ ->
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(* A block's tail is its last form and nothing else. Callers that must not
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pass one on need do nothing: [check] withdrew it before they were
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reached, so [tail] is already false here for all of them. *)
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let tail = ctx.tail in
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let used = ctx.used in
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ctx.used <- false;
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let rec go = function
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| [ last ] ->
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ctx.defer_ok <- defer_ok;
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ctx.tail <- tail;
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ctx.used <- used;
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let l = check ctx ?want last in [ l ], l.Tast.ty
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| x :: rest ->
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ctx.defer_ok <- defer_ok;
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ctx.tail <- false;
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ctx.used <- false;
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let x = check ctx x in
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let rest, ty = go rest in x :: rest, ty
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| [] -> assert false
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@ -7015,7 +7043,20 @@ and check_fn ctx ~want ?gen loc (params : string list) body =
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in
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List.iter2
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(fun n t -> ignore (bind fctx n t ~assignable:false)) params pts;
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let fbody = map_lr (fun e -> check fctx e) body in
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(* The last form is checked at the return type the position wants, as a
|
||||
defn's is at its declared one, so a value that takes its type from what
|
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is asked of it — a kept [when], [None], a bare struct — gets it here. *)
|
||||
let last_want =
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match ret0 with
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||||
| Some r when not (Types.equal r Types.Unit) -> Some r
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||||
| _ -> None
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in
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let n = List.length body in
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let fbody =
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map_lr
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(fun (i, e) -> if i = n - 1 then check fctx ?want:last_want e else check fctx e)
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(List.mapi (fun i e -> (i, e)) body)
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||||
in
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(* The same rule an ordinary defn's body follows: the last form is the
|
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answer, and it has to be the declared return type — or, when nothing
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||||
declared one ([ret0] is [None]), the last form's own type *is* the
|
||||
@ -7828,7 +7869,7 @@ and lit_conflict (k : Ast.expr) name t1 l1 t2 l2 =
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one it should have: %s"
|
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name (tyname l1 t1) (tyname l2 t2) lit fix
|
||||
|
||||
and check_let ctx ?(tail = false) ?want ?(defer_ok = false) loc bs body =
|
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and check_let ctx ?(tail = false) ?(used = false) ?want ?(defer_ok = false) loc bs body =
|
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with_lits ctx loc
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(List.filter_map
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(fun (b : Ast.binding) -> if b.Ast.bty = None then Some b.Ast.bval else None)
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||||
@ -7840,6 +7881,7 @@ and check_let ctx ?(tail = false) ?want ?(defer_ok = false) loc bs body =
|
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(fun (b : Ast.binding) ->
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let want = Option.map (resolve ctx.env) b.Ast.bty in
|
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let lit = if b.Ast.bty = None then lit_local ctx b.Ast.bname b.Ast.bval else None in
|
||||
ctx.used <- true;
|
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let v =
|
||||
match lit with
|
||||
| Some t -> lit_init ctx t b.Ast.bval
|
||||
@ -7863,6 +7905,7 @@ and check_let ctx ?(tail = false) ?want ?(defer_ok = false) loc bs body =
|
||||
in
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(* After the bindings, because checking each of them withdrew it. *)
|
||||
ctx.tail <- tail;
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||||
ctx.used <- used;
|
||||
let body = block ctx ?want ~defer_ok loc body in
|
||||
mk loc body.Tast.ty (Tast.Let (bs, [ body ])))
|
||||
|
||||
@ -8350,14 +8393,14 @@ and check_truthy_once ctx c =
|
||||
with Loc.Error d -> refuse_or_poison ctx.env loc d))
|
||||
| exception Loc.Error _ -> check ctx ~want:Types.Bool c
|
||||
|
||||
and check_if ctx ?(tail = false) ?want loc c t e =
|
||||
and check_if ctx ?(tail = false) ?(used = false) ?want loc c t e =
|
||||
if ctx.env.recovering && ctx.env.speculating = 0 then
|
||||
check_if_once ctx ~tail ?want loc c t e
|
||||
check_if_once ctx ~tail ~used ?want loc c t e
|
||||
else
|
||||
match
|
||||
List.find_opt
|
||||
(fun (n, (sc, r), w, _) ->
|
||||
n == c && r == ctx.ret && w = want && same_scope sc ctx.scope)
|
||||
n == c && r == ctx.ret && w = (want, used) && same_scope sc ctx.scope)
|
||||
(Hashtbl.find_all if_failed c.Ast.loc)
|
||||
with
|
||||
| Some (_, _, _, d) -> raise (Loc.Error d)
|
||||
@ -8369,23 +8412,56 @@ and check_if ctx ?(tail = false) ?want loc c t e =
|
||||
decr if_depth;
|
||||
if !if_depth = 0 then Hashtbl.reset if_failed)
|
||||
(fun () ->
|
||||
try check_if_once ctx ~tail ?want loc c t e
|
||||
try check_if_once ctx ~tail ~used ?want loc c t e
|
||||
with Loc.Error d as ex ->
|
||||
if !lit_recording = 0 then Hashtbl.add if_failed c.Ast.loc (c, (scope, ctx.ret), want, d);
|
||||
if !lit_recording = 0 then Hashtbl.add if_failed c.Ast.loc (c, (scope, ctx.ret), (want, used), d);
|
||||
raise ex)
|
||||
|
||||
and check_if_once ctx ~tail ?want loc c t e =
|
||||
and check_if_once ctx ~tail ~used ?want loc c t e =
|
||||
let c = check_truthy ctx c in
|
||||
(* Both arms are the tail, and a one-armed [if] counts: [(when c (recur ...))]
|
||||
is how nearly every loop is written, and the branch is still the last
|
||||
thing the body does. *)
|
||||
let in_tail f = ctx.tail <- tail; f () in
|
||||
thing the body does. Both arms are kept when the [if] is. *)
|
||||
let in_tail f = ctx.tail <- tail; ctx.used <- used; f () in
|
||||
match e with
|
||||
| None ->
|
||||
(* A one-armed if produces Unit whatever the branch evaluates to: there is
|
||||
no value on the missing side. `when` desugars to this. *)
|
||||
let t = branch ctx (fun () -> in_tail (fun () -> check ctx t)) in
|
||||
expect ctx loc ~want (mk loc Types.Unit (Tast.If (c, t, unit_at loc)))
|
||||
| None -> check_when ctx ~used ?want loc c (fun ?want () ->
|
||||
branch ctx (fun () -> in_tail (fun () -> check ctx ?want t)))
|
||||
(* A kept chain whose last else is missing — a [cond] with no [:else],
|
||||
whose fallthrough is [(do)], or an [if] whose else is a [when] — is one
|
||||
[when] spread over several tests: an Option, [None] when no test holds,
|
||||
and [Some] of the arm that ran. *)
|
||||
| Some e when kept_open ~used want e ->
|
||||
(match e.Ast.e with
|
||||
| Ast.Do [] ->
|
||||
check_when ctx ~used:true ?want loc c (fun ?want () ->
|
||||
branch ctx (fun () -> in_tail (fun () -> check ctx ?want t)))
|
||||
| _ ->
|
||||
let tw =
|
||||
match want with
|
||||
| Some (Types.Option i) -> Some i
|
||||
| Some Types.Dyn -> Some Types.Dyn
|
||||
| _ -> None
|
||||
in
|
||||
let t = branch ctx (fun () -> in_tail (fun () -> check ctx ?want:tw t)) in
|
||||
let rest ~used ?want () =
|
||||
branch ctx (fun () ->
|
||||
ctx.tail <- tail; ctx.used <- used; check ctx ?want e)
|
||||
in
|
||||
match t.Tast.ty with
|
||||
| Types.Unit ->
|
||||
expect ctx loc ~want
|
||||
(mk loc Types.Unit (Tast.If (c, t, rest ~used:false ())))
|
||||
| Types.Never ->
|
||||
let e = rest ~used:true ?want () in
|
||||
mk loc e.Tast.ty (Tast.If (c, t, e))
|
||||
| Types.Dyn ->
|
||||
let e = rest ~used:true ~want:Types.Dyn () in
|
||||
expect ctx loc ~want (mk loc Types.Dyn (Tast.If (c, t, e)))
|
||||
| ty ->
|
||||
let oty = Types.Option ty in
|
||||
let e = rest ~used:true ~want:oty () in
|
||||
expect ctx loc ~want
|
||||
(mk loc oty (Tast.If (c, mk loc oty (Tast.Some_ t), e))))
|
||||
(* Two literal arms meet at the wider of their own types, as two literal
|
||||
elements of an array do: [(if c 1 2.5)] is an f64. *)
|
||||
| Some e
|
||||
@ -8580,6 +8656,65 @@ and check_if_once ctx ~tail ?want loc c t e =
|
||||
in
|
||||
mk loc ty (Tast.If (c, t, e))
|
||||
|
||||
(* A one-armed [if], which [when] is. As a statement it is Unit whatever its
|
||||
branch evaluates to. Kept — a [let]'s value, an argument, a return, or
|
||||
anything else with a type wanted of it — it answers (Option T): [Some] of
|
||||
the branch when the test held and [None] when it did not. A branch that
|
||||
is already an Option is not flattened: the answer is (Option (Option T)),
|
||||
Rust's [bool::then], so [None] from the branch and a failed test stay two
|
||||
answers.
|
||||
|
||||
Dyn has no Option. Where a dyn is wanted, or the branch is a dyn, a false
|
||||
test answers nil and a true one the branch's value — one absence, as a
|
||||
dyn map's [get] has.
|
||||
|
||||
A branch with no value (Unit) or none at all (Never) keeps the statement's
|
||||
Unit, so what is refused about binding one is refused as before. *)
|
||||
and check_when ctx ~used ?want loc c
|
||||
(branch_at : ?want:Types.t -> unit -> Tast.expr) =
|
||||
let stmt t = expect ctx loc ~want (mk loc Types.Unit (Tast.If (c, t, unit_at loc))) in
|
||||
let nil () = rt loc Types.Dyn "flan_dyn_nil" [] in
|
||||
let valueless (t : Tast.expr) =
|
||||
match t.Tast.ty with Types.Unit | Types.Never -> true | _ -> false
|
||||
in
|
||||
match want with
|
||||
| Some (Types.Unit | Types.Never) -> stmt (branch_at ())
|
||||
| Some Types.Dyn ->
|
||||
let t = branch_at ~want:Types.Dyn () in
|
||||
mk loc Types.Dyn (Tast.If (c, t, nil ()))
|
||||
| Some (Types.Option inner) ->
|
||||
let t = branch_at ~want:inner () in
|
||||
let oty = Types.Option inner in
|
||||
let some = if t.Tast.ty = Types.Never then t else mk loc oty (Tast.Some_ t) in
|
||||
mk loc oty (Tast.If (c, some, mk loc oty Tast.None_))
|
||||
| None when not used -> stmt (branch_at ())
|
||||
| _ ->
|
||||
let t = branch_at () in
|
||||
if valueless t then stmt t
|
||||
else if Types.equal t.Tast.ty Types.Dyn then
|
||||
expect ctx loc ~want (mk loc Types.Dyn (Tast.If (c, t, nil ())))
|
||||
else
|
||||
let oty = Types.Option t.Tast.ty in
|
||||
expect ctx loc ~want
|
||||
(mk loc oty (Tast.If (c, mk loc oty (Tast.Some_ t), mk loc oty Tast.None_)))
|
||||
|
||||
(* Whether a two-armed [if] is kept and its else chain ends without one —
|
||||
[(do)], or a one-armed [if] — so the whole chain answers an Option. *)
|
||||
and kept_open ~used want (e : Ast.expr) =
|
||||
let kept =
|
||||
match want with
|
||||
| Some (Types.Unit | Types.Never) -> false
|
||||
| Some _ -> true
|
||||
| None -> used
|
||||
in
|
||||
let rec open_ (e : Ast.expr) =
|
||||
match e.Ast.e with
|
||||
| Ast.Do [] | Ast.If (_, _, None) | Ast.IfLet (_, _, None) -> true
|
||||
| Ast.If (_, _, Some e') | Ast.IfLet (_, _, Some e') -> open_ e'
|
||||
| _ -> false
|
||||
in
|
||||
kept && open_ e
|
||||
|
||||
(* The type two literals meet at, each at its own type — a wide integer at
|
||||
u64, which is the only type that holds one. *)
|
||||
and literal_join ctx (a : Ast.expr) (b : Ast.expr) =
|
||||
@ -9628,7 +9763,19 @@ and check_array_gen ctx ~want loc dims f =
|
||||
(array_build ctx loc ns elem ~pre:[ (fs, f) ]
|
||||
~element:(fun idxs -> mk loc elem (Tast.CallPtr (fv, idxs))))
|
||||
|
||||
and check_match ctx ?(tail = false) ?want loc scrutinee arms =
|
||||
and check_match ctx ?(tail = false) ?(used = false) ?(stmt = false) ?(opt = false)
|
||||
?opt_rest ?want loc scrutinee arms =
|
||||
(* [stmt] is an [if let] with no else: a statement, Unit whatever its arm
|
||||
answers, as a one-armed [if] is when nothing keeps it. [opt] is one that
|
||||
is kept: its arm answers [Some], and the arm with no body [None]. *)
|
||||
let used = used && not stmt in
|
||||
let arms_ast_for_opt = arms in
|
||||
let want0 = want in
|
||||
let want =
|
||||
if stmt then None
|
||||
else if opt then (match want with Some (Types.Option i) -> Some i | _ -> None)
|
||||
else want
|
||||
in
|
||||
let s = check ctx scrutinee in
|
||||
(* What the arms are alternatives over. An [Option] is a two-case data type
|
||||
wearing a special coat, so the two shapes below are the same shape: a set
|
||||
@ -10031,8 +10178,11 @@ and check_match ctx ?(tail = false) ?want loc scrutinee arms =
|
||||
(* Every arm is the tail, exactly as an [if]'s two arms are.
|
||||
Restored here because checking the scrutinee withdrew it. *)
|
||||
ctx.tail <- tail;
|
||||
ctx.used <- used;
|
||||
let arm = (a, ctor, binds) in
|
||||
let empty = opt && a.Ast.body = [] in
|
||||
let body =
|
||||
if empty then unit_at a.Ast.aloc else
|
||||
if free && !want <> None && not (literal_arm arm) then
|
||||
(* As an [if]'s else arm: at the join so far first, on its
|
||||
own terms only when that is refused as a mismatch. *)
|
||||
@ -10077,7 +10227,12 @@ and check_match ctx ?(tail = false) ?want loc scrutinee arms =
|
||||
| Error _ -> at !want ())
|
||||
else block ctx ?want:!want a.Ast.aloc a.Ast.body
|
||||
in
|
||||
(if body.Tast.ty <> Types.Never then
|
||||
let body =
|
||||
if stmt && body.Tast.ty <> Types.Unit && body.Tast.ty <> Types.Never
|
||||
then mk body.Tast.loc Types.Unit (Tast.Do [ body; unit_at body.Tast.loc ])
|
||||
else body
|
||||
in
|
||||
(if body.Tast.ty <> Types.Never && not stmt && not empty then
|
||||
match !want with
|
||||
| None -> want := Some body.Tast.ty
|
||||
| Some w when free ->
|
||||
@ -10109,8 +10264,11 @@ and check_match ctx ?(tail = false) ?want loc scrutinee arms =
|
||||
is said, as each would be checked at it. *)
|
||||
List.map
|
||||
(fun (i, (arm : Tast.arm)) ->
|
||||
let empty =
|
||||
opt && (let (a : Ast.arm), _, _ = List.nth resolved i in a.Ast.body = [])
|
||||
in
|
||||
match arm.Tast.abody with
|
||||
| [ b ] when not (Types.equal b.Tast.ty j || b.Tast.ty = Types.Never) ->
|
||||
| [ b ] when not (empty || Types.equal b.Tast.ty j || b.Tast.ty = Types.Never) ->
|
||||
let at = value_loc i in
|
||||
let b =
|
||||
try expect ctx at ~want:(Some j) b
|
||||
@ -10124,6 +10282,75 @@ and check_match ctx ?(tail = false) ?want loc scrutinee arms =
|
||||
let arms =
|
||||
List.map snd (List.sort (fun (i, _) (j, _) -> compare i j) checked)
|
||||
in
|
||||
(* [opt]: what the pattern's arm answered decides the whole, as a
|
||||
one-armed [if]'s branch does — no value is a statement, Never stays
|
||||
Never, a dyn is the value or nil, and anything else is [Some] of it. The
|
||||
arm with no body is the rest of the chain, [opt_rest], checked now that
|
||||
its want is known, or [None] when the chain ends here. *)
|
||||
let opt_result = ref None in
|
||||
let arms =
|
||||
if not opt then arms
|
||||
else
|
||||
let raw =
|
||||
List.fold_left2
|
||||
(fun acc (a : Ast.arm) (arm : Tast.arm) ->
|
||||
match a.Ast.body, arm.Tast.abody with
|
||||
| _ :: _, [ b ] -> Some b.Tast.ty
|
||||
| _ -> acc)
|
||||
None arms_ast_for_opt arms
|
||||
in
|
||||
let rest ~used ?want () =
|
||||
match opt_rest with
|
||||
| Some f -> Some (f ~used ?want ())
|
||||
| None -> None
|
||||
in
|
||||
let fill body_of wild_of =
|
||||
List.map2
|
||||
(fun (a : Ast.arm) (arm : Tast.arm) ->
|
||||
match a.Ast.body, arm.Tast.abody with
|
||||
| [], _ -> { arm with Tast.abody = [ wild_of a ] }
|
||||
| _, [ b ] -> { arm with Tast.abody = [ body_of b ] }
|
||||
| _ -> arm)
|
||||
arms_ast_for_opt arms
|
||||
in
|
||||
match raw with
|
||||
| None | Some Types.Unit ->
|
||||
opt_result := Some Types.Unit;
|
||||
let r = rest ~used:false () in
|
||||
fill Fun.id (fun a ->
|
||||
match r with
|
||||
| Some e when e.Tast.ty = Types.Unit || e.Tast.ty = Types.Never -> e
|
||||
| Some e -> mk e.Tast.loc Types.Unit (Tast.Do [ e; unit_at e.Tast.loc ])
|
||||
| None -> unit_at a.Ast.aloc)
|
||||
| Some Types.Never ->
|
||||
(match rest ~used:true ?want:want0 () with
|
||||
| Some e ->
|
||||
opt_result := Some e.Tast.ty;
|
||||
fill Fun.id (fun _ -> e)
|
||||
| None ->
|
||||
(match want0 with
|
||||
| Some (Types.Option _ as o) ->
|
||||
opt_result := Some o;
|
||||
fill Fun.id (fun a -> mk a.Ast.aloc o Tast.None_)
|
||||
| _ ->
|
||||
opt_result := Some Types.Unit;
|
||||
fill Fun.id (fun a -> unit_at a.Ast.aloc)))
|
||||
| Some Types.Dyn ->
|
||||
opt_result := Some Types.Dyn;
|
||||
let r = rest ~used:true ~want:Types.Dyn () in
|
||||
fill Fun.id (fun a ->
|
||||
match r with
|
||||
| Some e -> e
|
||||
| None -> rt a.Ast.aloc Types.Dyn "flan_dyn_nil" [])
|
||||
| Some t ->
|
||||
let oty = Types.Option t in
|
||||
opt_result := Some oty;
|
||||
let r = rest ~used:true ~want:oty () in
|
||||
fill (fun b -> mk b.Tast.loc oty (Tast.Some_ b)) (fun a ->
|
||||
match r with
|
||||
| Some e -> e
|
||||
| None -> mk a.Ast.aloc oty Tast.None_)
|
||||
in
|
||||
(* Exhaustiveness is refused, not defaulted. A match that silently fell
|
||||
through would have to produce a value of the match's type out of nothing,
|
||||
and there is no such value for most types; and the case a data type grows
|
||||
@ -10171,7 +10398,11 @@ and check_match ctx ?(tail = false) ?want loc scrutinee arms =
|
||||
(String.concat ", " missing)
|
||||
(if List.length missing = 1 then "has" else "have")
|
||||
(if List.length missing = 1 then "it" else "them");
|
||||
let ty = match !want with Some t -> t | None -> Types.Never in
|
||||
let ty =
|
||||
if stmt then Types.Unit
|
||||
else if opt then (match !opt_result with Some t -> t | None -> Types.Never)
|
||||
else match !want with Some t -> t | None -> Types.Never
|
||||
in
|
||||
match subject with
|
||||
| `Option _ | `Data _ -> mk loc ty (Tast.Match (s, arms))
|
||||
| `Enum _ | `Bool | `Lit _ ->
|
||||
@ -10207,6 +10438,80 @@ and check_match ctx ?(tail = false) ?want loc scrutinee arms =
|
||||
in
|
||||
mk loc ty (Tast.Let ([ (slot, s) ], [ chain arms ]))
|
||||
|
||||
(* [if let P = v] — (if-let [P v] then else) — is the two-arm match
|
||||
[(match v P then _ else)]. With no else it is a statement, Unit whatever
|
||||
[then] answers, as a one-armed [if] is.
|
||||
|
||||
A pattern that cannot fail — [_], or a plain name, which is a name to bind
|
||||
and not a case — tests nothing, and is refused toward [let]. A bare name is
|
||||
a case when some data type, Option or bool has a case of that name, or it
|
||||
names an enum member through its enum. *)
|
||||
and check_if_let ctx ~tail ~used ?want loc scrutinee (arm : Ast.arm) els =
|
||||
let fln = fln_source loc in
|
||||
let is_case n =
|
||||
List.mem n [ "None"; "Some"; "true"; "false" ]
|
||||
|| String.contains n '.'
|
||||
|| Hashtbl.fold
|
||||
(fun _ u acc -> acc || Tast.case_index u n <> None)
|
||||
ctx.env.datas false
|
||||
in
|
||||
let irrefutable name =
|
||||
match name with
|
||||
| Some n ->
|
||||
Loc.failk "check/if-let-irrefutable" arm.Ast.aloc
|
||||
"the pattern %s is a plain name, which always matches, so this if let \
|
||||
has nothing to test. Bind the value with %s"
|
||||
n
|
||||
(if fln then Printf.sprintf "let %s = ..." n
|
||||
else Printf.sprintf "(let [%s ...] ...)" n)
|
||||
| None ->
|
||||
Loc.failk "check/if-let-irrefutable" arm.Ast.aloc
|
||||
"the pattern _ always matches, so this if let has nothing to test. \
|
||||
Use the value directly, or match on it"
|
||||
in
|
||||
(match arm.Ast.pat with
|
||||
| Ast.Pwild -> irrefutable None
|
||||
| Ast.Pctor (n, []) when not (is_case n) -> irrefutable (Some n)
|
||||
| _ -> ());
|
||||
let wild body = { Ast.pat = Ast.Pwild; body; aloc = loc } in
|
||||
(* Kept with no else at the end of its chain, it is a [when] over a
|
||||
pattern: [Some] of the arm that ran and [None] when none did — or, where
|
||||
a dyn is wanted, the value or nil. *)
|
||||
let open_end =
|
||||
match els with None -> true | Some e -> kept_open ~used:true None e
|
||||
in
|
||||
let kept =
|
||||
match want with
|
||||
| Some (Types.Unit | Types.Never) -> false
|
||||
| Some _ -> true
|
||||
| None -> used
|
||||
in
|
||||
let at (x : Ast.expr) e = { Ast.e; loc = x.Ast.loc } in
|
||||
match els with
|
||||
| _ when kept && open_end ->
|
||||
let rest = match els with Some e -> e | None -> at scrutinee (Ast.Var "nil") in
|
||||
(match want with
|
||||
| Some Types.Dyn ->
|
||||
check_match ctx ~tail ~used:true ?want loc scrutinee [ arm; wild [ rest ] ]
|
||||
| _ ->
|
||||
(* The rest of the chain is checked once the arm's own type is
|
||||
known, as a one-armed [if]'s else is: see [opt] in [check_match]. *)
|
||||
let opt_rest =
|
||||
Option.map
|
||||
(fun e ~used ?want () ->
|
||||
branch ctx (fun () ->
|
||||
ctx.tail <- tail; ctx.used <- used; check ctx ?want e))
|
||||
els
|
||||
in
|
||||
expect ctx loc ~want
|
||||
(check_match ctx ~tail ~used:true ~opt:true ?opt_rest ?want loc scrutinee
|
||||
[ arm; wild [] ]))
|
||||
| Some e ->
|
||||
check_match ctx ~tail ~used ?want loc scrutinee [ arm; wild [ e ] ]
|
||||
| None ->
|
||||
expect ctx loc ~want
|
||||
(check_match ctx ~tail ~stmt:true loc scrutinee [ arm; wild [] ])
|
||||
|
||||
(* ── Places ────────────────────────────────────────────────────────── *)
|
||||
|
||||
(* The fields a name has, whether it is a struct or an untagged union. The two
|
||||
@ -10943,6 +11248,7 @@ and cast_operand ctx loc name ~needs ?also ~what ~is v =
|
||||
"%s converts %s. %s — %s" name what known fix
|
||||
|
||||
and fold_left_prim ctx ~want loc name p ~needs ok what args =
|
||||
refuse_kept_when ctx name args;
|
||||
let x, y, rest =
|
||||
match args with x :: y :: rest -> x, y, rest | _ -> assert false
|
||||
in
|
||||
@ -10975,6 +11281,58 @@ and fold_left_prim ctx ~want loc name p ~needs ok what args =
|
||||
expect ctx loc ~want acc
|
||||
end
|
||||
|
||||
(* An operand is kept, so a form with no else at its end — a [when], a
|
||||
[cond] or an [if]/[if let] chain with no final else, or a [do] or [let]
|
||||
ending in one — answers an Option there. Beside a number that is refused
|
||||
at the form itself, before the operands are checked against each other,
|
||||
where the number beside it would be blamed instead. One over a dyn answers
|
||||
a dyn, and that is left to the operator. *)
|
||||
and refuse_kept_when ctx name (args : Ast.expr list) =
|
||||
(* The form with no else, found at the end of [a]. *)
|
||||
let rec else_less (a : Ast.expr) =
|
||||
match a.Ast.e with
|
||||
| Ast.If (_, _, None) | Ast.IfLet (_, _, None) -> Some a
|
||||
| Ast.If (_, _, Some e) | Ast.IfLet (_, _, Some e) ->
|
||||
if open_tail e then Some a else None
|
||||
| Ast.Do (_ :: _ as xs) | Ast.Let (_, (_ :: _ as xs)) ->
|
||||
else_less (List.nth xs (List.length xs - 1))
|
||||
| _ -> None
|
||||
and open_tail (e : Ast.expr) =
|
||||
match e.Ast.e with
|
||||
| Ast.Do [] -> true
|
||||
| _ -> else_less e <> None
|
||||
in
|
||||
let ty (a : Ast.expr) = probe ctx a.Ast.loc (fun () -> (check ctx a).Tast.ty) in
|
||||
let number (a : Ast.expr) =
|
||||
match a.Ast.e with
|
||||
| Ast.Int _ | Ast.UInt _ | Ast.Float _ | Ast.Byte _ -> true
|
||||
| _ when else_less a <> None -> false
|
||||
| _ -> (match ty a with Some t -> Types.is_numeric t | None -> false)
|
||||
in
|
||||
List.iter
|
||||
(fun (a : Ast.expr) ->
|
||||
match else_less a with
|
||||
| Some form ->
|
||||
(match ty a with
|
||||
| Some (Types.Option _ as t)
|
||||
when List.exists (fun b -> b != a && number b) args ->
|
||||
let fln = fln_source form.Ast.loc in
|
||||
let what =
|
||||
match form.Ast.e with
|
||||
| Ast.If (_, _, None) -> if fln then "if without an else" else "when"
|
||||
| Ast.IfLet _ -> "if let without an else"
|
||||
| _ -> if fln then "if chain without an else" else "chain without an else"
|
||||
in
|
||||
Loc.failk "check/kept-when" form.Ast.loc
|
||||
"this %s is an operand of %s, so its value is kept, and there it \
|
||||
gives %s: Some of its value when a test holds, None when none \
|
||||
does. The other side is a number. Give it an else, or unwrap \
|
||||
what it gives with match"
|
||||
what name (tyname form.Ast.loc t)
|
||||
| _ -> ())
|
||||
| None -> ())
|
||||
args
|
||||
|
||||
(* The dyn lowering of a fold: one call per operator application, left to
|
||||
right, each taking and answering a dyn word. The typed side of a mixed pair
|
||||
is boxed on the way in — [box] is the identity on something already dyn, so
|
||||
@ -11591,6 +11949,148 @@ and vec_at ctx loc (target : Tast.expr) (idx : Ast.expr list) =
|
||||
fail loc
|
||||
"a Vec takes exactly one index, as (at v i)"
|
||||
|
||||
(* [(get xs i ...)] over an array, a slice, a string or a Vec: the element
|
||||
as [(Some e)], or [None] when any index is out of range, negative
|
||||
included, where [at] would trap. One index per dimension, as [at] takes.
|
||||
|
||||
The indices are evaluated once, left to right, before any test. An array's
|
||||
length is static, so the array itself is read once and is not copied; a
|
||||
slice's, a string's or a Vec's is read off the value, so that value is
|
||||
put in a slot first unless it is already a name. Each level is tested
|
||||
before the next is reached, because a Vec of Vecs has no inner length to
|
||||
test until the outer index is known to be in range. The element is then
|
||||
read by [at] as usual, whose own check can no longer fail. *)
|
||||
and checked_get ctx ~want loc (target : Tast.expr) (idx : Ast.expr list) =
|
||||
let rec result ty = function
|
||||
| [] -> ty
|
||||
| (i : Ast.expr) :: rest ->
|
||||
(match ty with
|
||||
| Types.Array (_, t) | Types.Slice (_, t) | Types.Vec t -> result t rest
|
||||
| Types.String -> result (Types.Int Types.U8) rest
|
||||
| other ->
|
||||
fail i.Ast.loc
|
||||
"get takes an array, a slice, a string, a Vec, a Map or a dyn, and \
|
||||
%s cannot be indexed" (tyname i.Ast.loc other))
|
||||
in
|
||||
let oty = Types.Option (result target.Tast.ty idx) in
|
||||
let none () = mk loc oty Tast.None_ in
|
||||
let is_name (e : Tast.expr) =
|
||||
match e.Tast.e with Tast.Local _ | Tast.Global _ -> true | _ -> false
|
||||
in
|
||||
(* A value a call answered is bound before the indices run, so the target
|
||||
is still evaluated first. *)
|
||||
let pre = ref [] in
|
||||
let target =
|
||||
match target.Tast.e with
|
||||
| Tast.Call _ | Tast.CallPtr _ ->
|
||||
let s = fresh_slot ctx target.Tast.ty in
|
||||
pre := [ (s, target) ];
|
||||
mk loc target.Tast.ty (Tast.Local s)
|
||||
| _ -> target
|
||||
in
|
||||
let islots =
|
||||
map_lr
|
||||
(fun (i : Ast.expr) ->
|
||||
let v = index_expr ctx i in
|
||||
let s = fresh_slot ctx index_ty in
|
||||
(s, v))
|
||||
idx
|
||||
in
|
||||
let ivar (s, _) = mk loc index_ty (Tast.Local s) in
|
||||
let i32 k = mk loc index_ty (Tast.Int (k, Types.I32)) in
|
||||
let within i len =
|
||||
let ge = mk loc Types.Bool (Tast.Prim (Tast.Ge, [ i; i32 0L ])) in
|
||||
let lt = mk loc Types.Bool (Tast.Prim (Tast.Lt, [ i; len ])) in
|
||||
mk loc Types.Bool (Tast.If (ge, lt, mk loc Types.Bool (Tast.Bool false)))
|
||||
in
|
||||
(* The value reached so far is [base] indexed by [path], innermost last. *)
|
||||
let reached base path ty =
|
||||
if path = [] then base
|
||||
else mk loc ty (Tast.Prim (Tast.At, base :: List.rev path))
|
||||
in
|
||||
(* A value whose length is read as well as indexed, in a slot unless it is
|
||||
a name already. *)
|
||||
let named cur k =
|
||||
if is_name cur then k cur
|
||||
else
|
||||
let s = fresh_slot ctx cur.Tast.ty in
|
||||
mk loc oty
|
||||
(Tast.Let ([ (s, cur) ], [ k (mk loc cur.Tast.ty (Tast.Local s)) ]))
|
||||
in
|
||||
let rec go base path ty = function
|
||||
| [] -> mk loc oty (Tast.Some_ (reached base path ty))
|
||||
| i :: rest ->
|
||||
let i = ivar i in
|
||||
(match ty with
|
||||
| Types.Array (n, t) ->
|
||||
mk loc oty (Tast.If (within i (i32 n), go base (i :: path) t rest, none ()))
|
||||
| Types.Slice _ | Types.String ->
|
||||
let t =
|
||||
match ty with Types.Slice (_, t) -> t | _ -> Types.Int Types.U8
|
||||
in
|
||||
named (reached base path ty) (fun cur ->
|
||||
let len = mk loc index_ty (Tast.Prim (Tast.Len, [ cur ])) in
|
||||
mk loc oty (Tast.If (within i len, go cur [ i ] t rest, none ())))
|
||||
| Types.Vec t ->
|
||||
named (reached base path ty) (fun cur ->
|
||||
let n = rt loc (Types.Int Types.I64) "flan_vec_len" [ cur; here loc ] in
|
||||
let len = mk loc index_ty (Tast.Prim (Tast.Cast index_ty, [ n ])) in
|
||||
let p =
|
||||
rt loc (Types.Ptr (Types.Mut, t)) "flan_vec_at"
|
||||
[ cur; i; size_of loc t; here loc ]
|
||||
in
|
||||
mk loc oty
|
||||
(Tast.If (within i len, go (mk loc t (Tast.Deref p)) [] t rest,
|
||||
none ())))
|
||||
| _ -> assert false)
|
||||
in
|
||||
expect ctx loc ~want
|
||||
(mk loc oty (Tast.Let (!pre @ islots, [ go target [] target.Tast.ty islots ])))
|
||||
|
||||
(* [(get d k ...)] over a dyn: a map's value at the key, a vec's or a text's
|
||||
element at the index, or nil when there is none — dyn has no Option. More
|
||||
than one key walks a level per key, and a nil level answers nil. *)
|
||||
and dyn_get ctx ~want loc (target : Tast.expr) (keys : Ast.expr list) =
|
||||
let nil () = rt loc Types.Dyn "flan_dyn_nil" [] in
|
||||
let one v k = rt loc Types.Dyn "flan_dyn_get_at" [ v; k; here loc ] in
|
||||
(* A slot per key only when there are several: one key goes straight to
|
||||
[flan_dyn_get_at]. Over a text or a vec that runs [at]'s own body in the
|
||||
runtime, so [get] and [at] count a text the same way whatever [at]
|
||||
comes to count. *)
|
||||
let slotted = List.length keys > 1 in
|
||||
let keys =
|
||||
map_lr
|
||||
(fun k ->
|
||||
let v = check ctx ~want:Types.Dyn k in
|
||||
((if slotted then fresh_slot ctx Types.Dyn else -1), v))
|
||||
keys
|
||||
in
|
||||
let kvar (s, _) = mk loc Types.Dyn (Tast.Local s) in
|
||||
let rec go v = function
|
||||
| [] -> v
|
||||
| k :: rest when rest = [] -> one v (kvar k)
|
||||
| k :: rest ->
|
||||
let s = fresh_slot ctx Types.Dyn in
|
||||
let sv = mk loc Types.Dyn (Tast.Local s) in
|
||||
let is_nil =
|
||||
mk loc Types.Bool
|
||||
(Tast.Prim (Tast.Ne,
|
||||
[ rt loc (Types.Int Types.I32) "flan_dyn_is_nil" [ sv ];
|
||||
mk loc (Types.Int Types.I32) (Tast.Int (0L, Types.I32)) ]))
|
||||
in
|
||||
mk loc Types.Dyn
|
||||
(Tast.Let ([ (s, one v (kvar k)) ],
|
||||
[ mk loc Types.Dyn (Tast.If (is_nil, nil (), go sv rest)) ]))
|
||||
in
|
||||
match keys with
|
||||
| [ (_, k) ] -> expect ctx loc ~want (one target k)
|
||||
| _ ->
|
||||
let ts = fresh_slot ctx Types.Dyn in
|
||||
expect ctx loc ~want
|
||||
(mk loc Types.Dyn
|
||||
(Tast.Let ((ts, target) :: keys,
|
||||
[ go (mk loc Types.Dyn (Tast.Local ts)) keys ])))
|
||||
|
||||
(* [(slice v)], [(slice v lo)] and [(slice v lo hi)] over a Vec — the arm for
|
||||
it is in [slice], and this is the half that differs from an array's.
|
||||
|
||||
@ -12227,6 +12727,7 @@ and named_call ?(qualified = false) ctx ~want loc name args =
|
||||
nobody writes on purpose. *)
|
||||
| "%" ->
|
||||
arity ctx loc name 2 args;
|
||||
refuse_kept_when ctx name args;
|
||||
let a, b = binary ctx ~dyn_ok:true name loc ~want:(numeric_want want) args in
|
||||
if a.Tast.ty = Types.Dyn || b.Tast.ty = Types.Dyn then
|
||||
dyn_fold ctx ~want loc name [ a; b ] []
|
||||
@ -12245,6 +12746,7 @@ and named_call ?(qualified = false) ctx ~want loc name args =
|
||||
let x, y, rest =
|
||||
match args with x :: y :: rest -> x, y, rest | _ -> assert false
|
||||
in
|
||||
refuse_kept_when ctx name args;
|
||||
if List.exists (fun a -> peeks_string ctx a) args then
|
||||
string_compare ctx ~want loc name p args
|
||||
else
|
||||
@ -13364,20 +13866,33 @@ and named_call ?(qualified = false) ctx ~want loc name args =
|
||||
There is no allocation here and therefore no guard: a lookup that finds
|
||||
nothing is an answer, not a failure. *)
|
||||
| "get" ->
|
||||
arity ctx loc name 2 args;
|
||||
(match args with
|
||||
| target :: (_ :: _ :: _ as idx) ->
|
||||
(* Two indices or more: an array, a slice or a Vec, one per
|
||||
dimension, or a dyn walked a level per index. A map takes one key. *)
|
||||
let target = check_target ctx target in
|
||||
(match target.Tast.ty with
|
||||
| Types.Map _ ->
|
||||
fail loc "a map's get takes one key, as (get m k), and this has %d"
|
||||
(List.length idx)
|
||||
| Types.Named "String" ->
|
||||
(ignore (refuse_string_index (List.hd idx).Ast.loc ~store:false); assert false)
|
||||
| Types.Dyn -> dyn_get ctx ~want loc target idx
|
||||
| _ -> checked_get ctx ~want loc target idx)
|
||||
| [ target; k ] ->
|
||||
let target = check_target ctx target in
|
||||
(match target.Tast.ty with
|
||||
| Types.Array _ | Types.Slice _ | Types.String | Types.Vec _ ->
|
||||
checked_get ctx ~want loc target [ k ]
|
||||
(* The same refusal [at] gives: a String is not indexed. *)
|
||||
| Types.Named "String" -> (ignore (refuse_string_index k.Ast.loc ~store:false); assert false)
|
||||
| Types.Dyn -> dyn_get ctx ~want loc target [ k ]
|
||||
| _ ->
|
||||
(* A dyn map's absence is nil, not None: the typed map can promise an
|
||||
(Option V) because V was written down, and a dyn map has nothing to
|
||||
write. nil is an ordinary dyn value the caller compares against —
|
||||
and (contains? m k) is the question to ask when nil might also be
|
||||
stored under the key. *)
|
||||
if target.Tast.ty = Types.Dyn then
|
||||
expect ctx loc ~want
|
||||
(rt loc Types.Dyn "flan_dyn_get"
|
||||
[ target; check ctx ~want:Types.Dyn k; here loc ])
|
||||
else begin
|
||||
let kt, vt = map_kv loc "get" target.Tast.ty in
|
||||
let k = check ctx ~want:kt k in
|
||||
(* Deferred, and the placeholder is [None] rather than [Unit]: this
|
||||
@ -13386,9 +13901,8 @@ and named_call ?(qualified = false) ctx ~want loc name args =
|
||||
if deferred_key ctx.env loc "get" kt then
|
||||
expect ctx loc ~want (mk loc (Types.Option vt) Tast.None_)
|
||||
else
|
||||
map_lookup ctx ~want loc "flan_map_get" target kt vt k
|
||||
end
|
||||
| _ -> assert false)
|
||||
map_lookup ctx ~want loc "flan_map_get" target kt vt k)
|
||||
| _ -> arity ctx loc name 2 args; assert false)
|
||||
|
||||
(* (keyword s) -> the interned dyn keyword named by the bytes, for a name
|
||||
that only exists at run time — a reader building :texture-path out of a
|
||||
@ -15689,7 +16203,7 @@ and trial ctx f =
|
||||
let[@warning "+9"] { env = _; ret = _; lits = _; slots; slot_tys; slot_names; scope;
|
||||
defers; defer_slot; defer_ok; defer_block; outer = _;
|
||||
outer_what; caught; place_ok; envslot; parent = _;
|
||||
in_frames; loops; tail; in_defer;
|
||||
in_frames; loops; tail; used; kept; in_defer;
|
||||
owner = _ } = ctx in
|
||||
let undo, keep = snapshot_env ctx.env in
|
||||
match speculate ctx.env f with
|
||||
@ -15702,7 +16216,8 @@ and trial ctx f =
|
||||
ctx.defer_ok <- defer_ok; ctx.defer_block <- defer_block;
|
||||
ctx.outer_what <- outer_what; ctx.in_frames <- in_frames;
|
||||
ctx.caught <- caught; ctx.place_ok <- place_ok; ctx.envslot <- envslot;
|
||||
ctx.loops <- loops; ctx.tail <- tail; ctx.in_defer <- in_defer;
|
||||
ctx.loops <- loops; ctx.tail <- tail; ctx.used <- used; ctx.kept <- kept;
|
||||
ctx.in_defer <- in_defer;
|
||||
Error d
|
||||
| exception e -> keep (); raise e
|
||||
|
||||
@ -16160,10 +16675,13 @@ let builtins : (string * string * string) list =
|
||||
("put", "put [(Map K V) K V] ()",
|
||||
"Inserts or replaces. Unit rather than an error code, and \
|
||||
(set (get m k) v) is not map syntax.");
|
||||
("get", "get [(Map K V) K] (Option V)",
|
||||
("get", "get [(Map K V) K]|[collection i32 ...] (Option V)|(Option T)",
|
||||
"The value at the key, or None. Nothing signals here — a lookup that \
|
||||
finds nothing is an answer — and the value comes back as a copy of \
|
||||
its bytes.");
|
||||
its bytes. Over an array, a slice, a string or a Vec it is at that \
|
||||
answers None for an index out of range, negative included, one index \
|
||||
per dimension. Over a dyn it answers nil for an absent key or index, \
|
||||
and more keys walk a level each.");
|
||||
("map-remove", "map-remove [(Map K V) K] (Option V)",
|
||||
"Removes the entry and answers the value it held, or None if there was \
|
||||
none.");
|
||||
@ -17177,6 +17695,9 @@ let escaping_names ~returns (body : Ast.expr list) : string list =
|
||||
| Ast.Do es | Ast.Let (_, es) ->
|
||||
(match List.rev es with x :: _ -> tails x | [] -> ())
|
||||
| Ast.If (_, a, b) -> tails a; Option.iter tails b
|
||||
| Ast.IfLet (_, a, b) ->
|
||||
(match List.rev a.Ast.body with x :: _ -> tails x | [] -> ());
|
||||
Option.iter tails b
|
||||
| Ast.Match (_, arms) ->
|
||||
List.iter
|
||||
(fun (a : Ast.arm) ->
|
||||
|
||||
@ -5074,6 +5074,7 @@ declare void @flan_dyn_class_hook(ptr)
|
||||
declare i64 @flan_dyn_kw(ptr, i64)
|
||||
declare i64 @flan_dyn_map_get(i64, i64)
|
||||
declare i64 @flan_dyn_get(i64, i64, ptr, i64)
|
||||
declare i64 @flan_dyn_get_at(i64, i64, ptr, i64)
|
||||
declare void @flan_dyn_map_set(i64, i64, i64)
|
||||
declare i64 @flan_dyn_map_contains(i64, i64)
|
||||
declare i64 @flan_dyn_map_contains_at(i64, i64, ptr, i64)
|
||||
|
||||
@ -536,8 +536,19 @@ and list f h args =
|
||||
("fn(" ^ commas ps ^ ") => " ^ unit_text body, 0)
|
||||
| Form.Sym "if", [ c; a; b ] ->
|
||||
("if " ^ at 1 c ^ " then " ^ inline_text ~lvl:1 a ^ " else " ^ inline_text b, 0)
|
||||
(* A used when is a value, [when c then a]. *)
|
||||
| Form.Sym "when", [ c; a ] -> ("when " ^ at 1 c ^ " then " ^ inline_text a, 0)
|
||||
| Form.Sym "if-let", ({ v = Form.Vec [ _; _ ]; _ } as hd) :: a :: ([] | [ _ ] as b) ->
|
||||
(if_let_head hd ^ " then " ^ inline_text ~lvl:1 a
|
||||
^ (match b with [ b ] -> " else " ^ inline_text b | _ -> ""), 0)
|
||||
| _ -> call ()
|
||||
|
||||
(* [if let P = v], the head (if-let [P v] ...) is written with. *)
|
||||
and if_let_head (hd : Form.t) =
|
||||
match hd.v with
|
||||
| Form.Vec [ pat; v ] -> "if let " ^ at 11 pat ^ " = " ^ at 1 v
|
||||
| _ -> assert false
|
||||
|
||||
(* A one-line slot's text — an arm's value, a then or an else, what follows
|
||||
defer: the statements that fit on a line are written as statements,
|
||||
everything else as a value. [lvl] is what a value in the slot needs. *)
|
||||
@ -700,7 +711,7 @@ let body_guess (h : Form.t) args =
|
||||
match a.v with
|
||||
| Form.List _ when is_chain a -> false
|
||||
| Form.List ({ v = Form.Sym h; _ } :: _) ->
|
||||
List.mem h [ "let"; "set"; "when"; "unless"; "cond"; "while";
|
||||
List.mem h [ "let"; "set"; "when"; "if-let"; "unless"; "cond"; "while";
|
||||
"until"; "dotimes"; "match"; "handler-case";
|
||||
"handler-bind"; "restart-case"; "return"; "defer";
|
||||
"do"; "break"; "continue" ]
|
||||
@ -772,7 +783,7 @@ let body_split (h : Form.t) args =
|
||||
| Some k, _ -> Some (k, false)
|
||||
|
||||
let sugar_heads =
|
||||
[ "let"; "set"; "if"; "when"; "cond"; "while"; "until"; "dotimes"; "match";
|
||||
[ "let"; "set"; "if"; "when"; "if-let"; "cond"; "while"; "until"; "dotimes"; "match";
|
||||
"handler-case"; "handler-bind"; "restart-case"; "return"; "defer"; "do";
|
||||
"quasiquote"; "update" ]
|
||||
|
||||
@ -1045,6 +1056,33 @@ and value_lines n prefix (v : Form.t) =
|
||||
|
||||
and slot n (f : Form.t) = block n (stmts_of f)
|
||||
|
||||
(* Whether an else is a chain the reader makes of an [elif let]: an if-let,
|
||||
or an [if] whose own else is one. *)
|
||||
and has_let_else (x : Form.t) =
|
||||
match x.v with
|
||||
| Form.List ({ v = Form.Sym "if-let"; _ } :: { v = Form.Vec [ _; _ ]; _ } :: _ :: ([] | [ _ ])) -> true
|
||||
| Form.List [ { v = Form.Sym "if"; _ }; _; _; r ] -> has_let_else r
|
||||
| _ -> false
|
||||
|
||||
(* Such a chain as the elif and else clauses at column [n]. A [when] at its
|
||||
end is an [elif] with no else after it, which is how the reader reads one
|
||||
back. *)
|
||||
and let_chain n (x : Form.t) =
|
||||
let i = ind n in
|
||||
let tag (x : Form.t) l = Source_text.tag x.loc.Loc.line l in
|
||||
match x.v with
|
||||
| Form.List ({ v = Form.Sym "if-let"; _ } :: ({ v = Form.Vec [ _; _ ]; _ } as hd) :: a
|
||||
:: ([] | [ _ ] as r)) ->
|
||||
(tag x (i ^ "el" ^ if_let_head hd) :: slot (n + 2) a)
|
||||
@ (match r with [ r ] -> let_chain n r | _ -> [])
|
||||
(* Past an [elif let] every clause nests, so an [if] here is an [elif]
|
||||
whether or not another let follows. *)
|
||||
| Form.List [ { v = Form.Sym "if"; _ }; c; a; r ] ->
|
||||
(tag c (i ^ "elif " ^ at 1 c) :: slot (n + 2) a) @ let_chain n r
|
||||
| Form.List ({ v = Form.Sym "when"; _ } :: c :: (_ :: _ as body)) ->
|
||||
tag c (i ^ "elif " ^ at 1 c) :: block (n + 2) body
|
||||
| _ -> tag x (i ^ "else") :: slot (n + 2) x
|
||||
|
||||
and label_of = function
|
||||
| ({ Form.v = Form.Kw k; _ }) :: rest when kw_ok k -> (":" ^ k ^ " ", rest)
|
||||
| rest -> ("", rest)
|
||||
@ -1080,6 +1118,9 @@ and sugar n (f : Form.t) : string list option =
|
||||
| _ -> simple x
|
||||
in
|
||||
let line = i ^ fst (expr f) in
|
||||
if has_let_else b then
|
||||
Some (((i ^ "if " ^ at 1 c) :: slot (n + 2) a) @ let_chain n b)
|
||||
else
|
||||
if simple a && chain b && String.length line <= width && not (!inside f)
|
||||
then Some [ line ]
|
||||
else
|
||||
@ -1088,6 +1129,50 @@ and sugar n (f : Form.t) : string list option =
|
||||
@ [ Source_text.tag b.loc.Loc.line (i ^ "else") ] @ slot (n + 2) b)
|
||||
| Form.List ({ v = Form.Sym "when"; _ } :: c :: (_ :: _ as body)) ->
|
||||
Some ((i ^ "if " ^ at 1 c) :: block (n + 2) body)
|
||||
(* [if let P = v] and its block; an else that is a cond is its elif
|
||||
chain, which is what the reader makes of one. *)
|
||||
| Form.List
|
||||
({ v = Form.Sym "if-let"; _ } :: ({ v = Form.Vec [ _; _ ]; _ } as hd) :: a
|
||||
:: ([] | [ _ ] as b)) ->
|
||||
let simple (x : Form.t) =
|
||||
match x.v with
|
||||
| Form.List ({ v = Form.Sym ("return" | "set" | "break" | "continue"); _ } :: _) -> true
|
||||
| Form.List ({ v = Form.Sym h; _ } :: _) -> not (List.mem h sugar_heads)
|
||||
| _ -> true
|
||||
in
|
||||
let line = i ^ fst (expr f) in
|
||||
if simple a && List.for_all simple b && String.length line <= width
|
||||
&& not (!inside f)
|
||||
then Some [ line ]
|
||||
else
|
||||
let head = (i ^ if_let_head hd) :: slot (n + 2) a in
|
||||
(match b with
|
||||
| [] -> Some head
|
||||
| [ e ] when has_let_else e -> Some (head @ let_chain n e)
|
||||
| [ ({ v = Form.List ({ v = Form.Sym "cond"; _ } :: args); _ } as e) ] ->
|
||||
(match pairs args with
|
||||
| Some (_ :: _ as prs) ->
|
||||
let tests, else_ =
|
||||
match List.rev prs with
|
||||
| (k, e) :: rest when is_else k -> (List.rev rest, Some (k, e))
|
||||
| _ -> (prs, None)
|
||||
in
|
||||
Some
|
||||
(head
|
||||
@ List.concat_map
|
||||
(fun ((c : Form.t), b) ->
|
||||
Source_text.tag c.loc.Loc.line (i ^ "elif " ^ at 1 c)
|
||||
:: slot (n + 2) b)
|
||||
tests
|
||||
@ (match else_ with
|
||||
| Some ((k : Form.t), e) ->
|
||||
Source_text.tag k.loc.Loc.line (i ^ "else") :: slot (n + 2) e
|
||||
| None -> []))
|
||||
| _ ->
|
||||
Some (head @ [ Source_text.tag e.loc.Loc.line (i ^ "else") ] @ slot (n + 2) e))
|
||||
| [ e ] ->
|
||||
Some (head @ [ Source_text.tag e.loc.Loc.line (i ^ "else") ] @ slot (n + 2) e)
|
||||
| _ -> None)
|
||||
| Form.List ({ v = Form.Sym "cond"; _ } :: args) ->
|
||||
(match pairs args with
|
||||
| None -> None
|
||||
|
||||
@ -823,6 +823,13 @@ let no_loop loc word =
|
||||
break leaves the loop early, and continue goes on to the next round."
|
||||
word
|
||||
|
||||
(* A [when] has one branch; an else under one is an if's. *)
|
||||
let when_else p =
|
||||
failk "when-else" (peek p).loc
|
||||
"a when has no else — it answers Some of its value when the test holds \
|
||||
and None when it does not. For two branches write if c then a else b, \
|
||||
or an if with an else block"
|
||||
|
||||
(* A refused chain written out as the [and] of all its tests. A middle
|
||||
operand that is more than a name or a literal is named by a [let] first,
|
||||
so the rewrite does not run it twice. *)
|
||||
@ -991,7 +998,7 @@ and primary p : Form.t * int =
|
||||
| NAME s ->
|
||||
let nxt = peek_at p 1 in
|
||||
let glued_lp = nxt.tok = LP && not nxt.sp in
|
||||
if s = "if" && nxt.sp && starts_value nxt.tok then if_expr p
|
||||
if (s = "if" || s = "when") && nxt.sp && starts_value nxt.tok then if_expr p
|
||||
else if s = "fn" && glued_lp then fn_expr p
|
||||
(* Only the Lisp loop's spellings are refused here, for a message at the
|
||||
word: [loop x = a, ...], [loop([...]):], a bare [loop] over a block
|
||||
@ -1090,30 +1097,76 @@ and primary p : Form.t * int =
|
||||
failk "expected-value" (where_ p) "expected a value here, and found %s"
|
||||
(show tk)
|
||||
|
||||
(* [if c then a else b]: the one-line form, for a value. *)
|
||||
(* [if c then a else b]: the one-line form, for a value. [if let P = v then
|
||||
a else b] and [when c then a] too. *)
|
||||
and if_expr p =
|
||||
let t = advance p in
|
||||
let c, _ = binary p 1 in
|
||||
let word = match t.tok with NAME w -> w | _ -> "if" in
|
||||
let letp = if word = "if" then if_let_head p else None in
|
||||
let c = match letp with Some m -> m | None -> fst (binary p 1) in
|
||||
(match (peek p).tok with
|
||||
| NAME "then" -> ignore (advance p)
|
||||
| _ ->
|
||||
failk "if-then" (where_ p)
|
||||
"an if inside a line is if c then a else b, and there is no then \
|
||||
after %s. Write the then, or start the if on its own line with its \
|
||||
"an %s inside a line is %s, and there is no then \
|
||||
after %s. Write the then, or start the %s on its own line with its \
|
||||
branches indented under it"
|
||||
(text_of c));
|
||||
word
|
||||
(if word = "when" then "when c then a" else "if c then a else b")
|
||||
(text_of c) word);
|
||||
let a = inline_stmt p in
|
||||
match (peek p).tok with
|
||||
| NAME ("else" | "elif") when word = "when" -> when_else p
|
||||
| NAME "else" ->
|
||||
ignore (advance p);
|
||||
let b = inline_stmt p in
|
||||
(mk p t.loc (Form.List [ sym t.loc "if"; c; a; b ]), 0)
|
||||
(if_let_wrap letp (mk p t.loc (Form.List [ sym t.loc "if"; c; a; b ])), 0)
|
||||
| NAME "elif" ->
|
||||
failk "one-line-elif" (peek p).loc
|
||||
"a one-line if has then and else and no elif. Chain another if after \
|
||||
the else — if a then x else if b then y else z — or write the if over \
|
||||
several lines, where elif goes"
|
||||
| _ -> (mk p t.loc (Form.List [ sym t.loc "when"; c; a ]), 0)
|
||||
| _ -> (if_let_wrap letp (mk p t.loc (Form.List [ sym t.loc "when"; c; a ])), 0)
|
||||
|
||||
(* [if let P = v]: after the [if], the pattern and the value, as the one form
|
||||
[[P v]] that stands where the test would. [None] when no [let] follows. *)
|
||||
and if_let_head p =
|
||||
match (peek p).tok, (peek_at p 1) with
|
||||
| NAME "let", n when n.sp ->
|
||||
let lt = advance p in
|
||||
let pat, _ = unary p in
|
||||
expect_name p "=" ~what:"= and the value the pattern is matched against";
|
||||
let v, _ = binary p 1 in
|
||||
Some (mk p lt.loc (Form.Vec [ pat; v ]))
|
||||
| _ -> None
|
||||
|
||||
(* The if an [if let] head was read into, rewritten to (if-let [P v] then
|
||||
else): [(if [P v] a b)], [(when [P v] body ...)] and an elif chain's
|
||||
[(cond [P v] a c2 b2 ...)], whose rest is the else. *)
|
||||
and if_let_wrap letp (f : Form.t) =
|
||||
match letp with
|
||||
| None -> f
|
||||
| Some m ->
|
||||
let il (h : Form.t) items =
|
||||
{ f with Form.v = Form.List (sym h.Form.loc "if-let" :: m :: items) }
|
||||
in
|
||||
let body (h : Form.t) = function
|
||||
| [ x ] -> x
|
||||
| (x : Form.t) :: _ as xs ->
|
||||
Form.make (Form.List (sym x.Form.loc "do" :: xs)) x.Form.loc
|
||||
| [] -> Form.make (Form.List [ sym h.Form.loc "do" ]) h.Form.loc
|
||||
in
|
||||
match f.Form.v with
|
||||
| Form.List (({ v = Form.Sym "if"; _ } as h) :: c :: rest) when c == m -> il h rest
|
||||
| Form.List (({ v = Form.Sym "when"; _ } as h) :: c :: b) when c == m ->
|
||||
il h [ body h b ]
|
||||
| Form.List (({ v = Form.Sym "cond"; _ } as h) :: c :: b1 :: rest) when c == m ->
|
||||
(match rest with
|
||||
| [] -> il h [ b1 ]
|
||||
| [ { v = Form.Kw "else"; _ }; e ] -> il h [ b1; e ]
|
||||
| (c2 : Form.t) :: _ ->
|
||||
il h [ b1; Form.make (Form.List (sym c2.Form.loc "cond" :: rest)) c2.Form.loc ])
|
||||
| _ -> f
|
||||
|
||||
(* What a one-line slot takes — a match arm's value, a then or an else, the
|
||||
thing after defer: a value, or one of the statements that fit on a line,
|
||||
@ -1529,7 +1582,7 @@ let header_follow p s =
|
||||
| "fn" | "fn-" | "def" | "once" | "const" | "struct" | "union" | "data"
|
||||
| "enum" | "import" ->
|
||||
n.sp && plain_name n.tok
|
||||
| "if" | "while" | "until" | "match" | "let" | "for" ->
|
||||
| "if" | "when" | "while" | "until" | "match" | "let" | "for" ->
|
||||
n.sp && starts_value n.tok
|
||||
&& (match n.tok with
|
||||
| NAME x when x = "=" || List.mem_assoc x assign_ops -> false
|
||||
@ -1716,7 +1769,8 @@ and value_line ?(block_ok = false) (s : st) ~after : Form.t =
|
||||
| NAME (("match" | "handler-case" | "handler-bind" | "restart-case") as w)
|
||||
when header_follow p w ->
|
||||
header s w
|
||||
| NAME "if" when header_follow p "if" && not (then_on_line p) -> header s "if"
|
||||
| NAME (("if" | "when") as w) when header_follow p w && not (then_on_line p) ->
|
||||
header s w
|
||||
| _ ->
|
||||
let e, _ = expr p in
|
||||
match (peek p).tok with
|
||||
@ -2317,17 +2371,27 @@ and header (s : st) w : Form.t =
|
||||
in
|
||||
expect_eol p ~after:(text_of path);
|
||||
form [ alias; path ]
|
||||
| "if" ->
|
||||
let c, _ = binary p 1 in
|
||||
| "if" | "when" ->
|
||||
let letp = if w = "if" then if_let_head p else None in
|
||||
let c = match letp with Some m -> m | None -> fst (binary p 1) in
|
||||
(* The elif and else clauses at the if's column, then the whole form.
|
||||
[oneline] when the if was [if c then a]: its clauses may then be
|
||||
one-line too, [elif c then x] and [else y], or take blocks. *)
|
||||
let clauses ~oneline body =
|
||||
(match (peek p).tok with
|
||||
| NAME ("else" | "elif") when w = "when" && not (assigns p) -> when_else p
|
||||
| _ -> ());
|
||||
(* The [elif let P = v] heads, as the [[P v]] each stands as. *)
|
||||
let elif_lets = ref [] in
|
||||
let rec elifs acc =
|
||||
match (peek p).tok with
|
||||
| NAME "elif" when not (assigns p) ->
|
||||
ignore (advance p);
|
||||
let c, _ = binary p 1 in
|
||||
let c =
|
||||
match if_let_head p with
|
||||
| Some m -> elif_lets := m :: !elif_lets; m
|
||||
| None -> fst (binary p 1)
|
||||
in
|
||||
(match (peek p).tok with
|
||||
| NAME "then" when oneline ->
|
||||
ignore (advance p);
|
||||
@ -2363,8 +2427,27 @@ and header (s : st) w : Form.t =
|
||||
| _ -> None
|
||||
in
|
||||
match els_, else_ with
|
||||
| _ when !elif_lets <> [] ->
|
||||
(* An [elif let] makes the rest of the chain the else of an if-let:
|
||||
each clause nests in the one before it, [if] or [if-let] as its
|
||||
head is, and a chain with no else ends in a [when]. *)
|
||||
let is_let c = List.memq c !elif_lets || Some c == letp in
|
||||
let rec build = function
|
||||
| [] -> Option.map (fun (el, e) -> blk s el e) else_
|
||||
| ((c : Form.t), b) :: rest ->
|
||||
let at = c.Form.loc in
|
||||
let f items = Form.make (Form.List items) at in
|
||||
let r = build rest in
|
||||
Some
|
||||
(if is_let c then f (sym at "if-let" :: c :: blk s at b :: Option.to_list r)
|
||||
else
|
||||
match r with
|
||||
| None -> f (sym at "when" :: c :: b)
|
||||
| Some r -> f [ sym at "if"; c; blk s at b; r ])
|
||||
in
|
||||
Option.get (build ((c, body) :: els_))
|
||||
| [], None -> named "when" (c :: body)
|
||||
| [], Some (el, e) -> form [ c; blk s l0 body; blk s el e ]
|
||||
| [], Some (el, e) -> named "if" [ c; blk s l0 body; blk s el e ]
|
||||
| _ ->
|
||||
let pairs =
|
||||
List.concat_map (fun (c, b) -> [ c; blk s c.Form.loc b ]) ((c, body) :: els_)
|
||||
@ -2376,15 +2459,17 @@ and header (s : st) w : Form.t =
|
||||
in
|
||||
named "cond" (pairs @ tail)
|
||||
in
|
||||
if_let_wrap letp @@
|
||||
(match (peek p).tok with
|
||||
| NAME "then" ->
|
||||
ignore (advance p);
|
||||
let a = inline_stmt p in
|
||||
(match (peek p).tok with
|
||||
| NAME ("else" | "elif") when w = "when" -> when_else p
|
||||
| NAME "else" ->
|
||||
ignore (advance p);
|
||||
let b = inline_stmt p in
|
||||
let f = form [ c; a; b ] in
|
||||
let f = named "if" [ c; a; b ] in
|
||||
expect_eol p ~after:(text_of f);
|
||||
f
|
||||
| NAME "elif" ->
|
||||
|
||||
@ -279,6 +279,14 @@ let rec rename_expr owned alias bound (e : Ast.expr) : Ast.expr =
|
||||
in
|
||||
{ a with Ast.body = List.map (rename_expr owned alias bound)
|
||||
a.Ast.body }) arms)
|
||||
| Ast.IfLet (sc, a, e') ->
|
||||
let inner =
|
||||
match a.Ast.pat with Ast.Pctor (_, ns) -> ns @ bound | _ -> bound
|
||||
in
|
||||
Ast.IfLet (go sc,
|
||||
{ a with Ast.body = List.map (rename_expr owned alias inner)
|
||||
a.Ast.body },
|
||||
Option.map go e')
|
||||
(* A quoted symbol naming something the package declares.
|
||||
[(Form.Sym {.s "Cursor"})] is what a quasiquote desugars to, and it is
|
||||
the one place a package's name survives into a *string* — which is
|
||||
@ -840,6 +848,7 @@ let rec expr_uses acc (e : Ast.expr) =
|
||||
| Ast.Call (h, args) -> go h; gos args
|
||||
| Ast.Match (sc, arms) ->
|
||||
go sc; List.iter (fun (a : Ast.arm) -> gos a.Ast.body) arms
|
||||
| Ast.IfLet (sc, a, e') -> go sc; gos a.Ast.body; Option.iter go e'
|
||||
| Ast.Struct (n, kvs) ->
|
||||
acc := (n, e.Ast.loc) :: !acc;
|
||||
List.iter (fun (_, v) -> go v) kvs
|
||||
|
||||
@ -38,7 +38,7 @@ let rec flat spell (f : Form.t) =
|
||||
(* Heads whose arguments are statements or clauses rather than values: these
|
||||
break one argument to a line, never filled. *)
|
||||
let statement_heads =
|
||||
[ "let"; "loop"; "set"; "if"; "when"; "unless"; "cond"; "while"; "until";
|
||||
[ "let"; "loop"; "set"; "if"; "if-let"; "when"; "unless"; "cond"; "while"; "until";
|
||||
"dotimes"; "match"; "handler-case"; "handler-bind"; "restart-case";
|
||||
"return"; "defer"; "do"; "fn"; "with-allocator"; "comment"; "quasiquote";
|
||||
"break"; "continue" ]
|
||||
|
||||
12
lib/parse.ml
12
lib/parse.ml
@ -489,6 +489,18 @@ and form f mk (head : Form.t) (args : Form.t list) : Ast.expr =
|
||||
|
||||
| Sym "cond" -> cond f args
|
||||
|
||||
(* (if-let [pattern value] then) and (if-let [pattern value] then else):
|
||||
[value] is matched against [pattern], whose names are bound in [then]
|
||||
only. Any [match] pattern may stand there. *)
|
||||
| Sym "if-let" ->
|
||||
(match args with
|
||||
| { v = Vec [ p; v ]; _ } :: t :: rest when List.length rest <= 1 ->
|
||||
let arm = { Ast.pat = pattern p; body = [ expr t ]; aloc = p.loc } in
|
||||
mk (Ast.IfLet (expr v, arm, Option.map expr (List.nth_opt rest 0)))
|
||||
| _ ->
|
||||
fail f "if-let is (if-let [pattern value] then) or \
|
||||
(if-let [pattern value] then else)")
|
||||
|
||||
(* Short-circuiting, so they cannot be ordinary calls. *)
|
||||
| Sym "and" -> shortcircuit f args ~is_and:true
|
||||
| Sym "or" -> shortcircuit f args ~is_and:false
|
||||
|
||||
@ -4890,44 +4890,62 @@ static int64_t need_index(const uint8_t *loc, int64_t loclen, const char *op,
|
||||
}
|
||||
|
||||
/* A text answers its [i]th char, counting code points: O(1) on an ASCII
|
||||
* text, a walk from the front on any other. A typed str counts bytes. */
|
||||
flan_dyn flan_dyn_at(flan_dyn v, flan_dyn i, const uint8_t *loc,
|
||||
int64_t loclen) {
|
||||
* text, a walk from the front on any other. A typed str counts bytes.
|
||||
*
|
||||
* [at]'s, and [get]'s over a text or a vec: one body, so the two always
|
||||
* count the same way. [soft] is [get]'s — an index out of range is nil
|
||||
* rather than a trap. */
|
||||
static flan_dyn at_core(flan_dyn v, flan_dyn i, const uint8_t *loc,
|
||||
int64_t loclen, int soft, const char *op) {
|
||||
int64_t k;
|
||||
flan_obj *o;
|
||||
/* m[:k] on a map is (get m :k), whatever the key: get's rule, nil when
|
||||
* absent. */
|
||||
if (is_map(v)) return flan_dyn_get(v, i, loc, loclen);
|
||||
if (!is_text(v) && !is_vec(v))
|
||||
trap2(loc, loclen, TYPE_TRAP, "at", "only a text, a vec or a map is indexed",
|
||||
trap2(loc, loclen, TYPE_TRAP, op, "only a text, a vec or a map is indexed",
|
||||
v, i);
|
||||
k = need_index(loc, loclen, "at", v, i);
|
||||
k = need_index(loc, loclen, op, v, i);
|
||||
o = dyn_obj(v);
|
||||
if (o->kind == OBJ_VIEW) {
|
||||
int64_t len = view_len(loc, loclen, "at", o);
|
||||
if (k < 0 || k >= len) trap_range(loc, loclen, "at", v, k, len);
|
||||
int64_t len = view_len(loc, loclen, op, o);
|
||||
if (k < 0 || k >= len) {
|
||||
if (soft) return flan_dyn_nil();
|
||||
trap_range(loc, loclen, op, v, k, len);
|
||||
}
|
||||
{
|
||||
uint8_t *p = view_elem_at(o, k);
|
||||
switch ((o->gen >> 9) & 3) {
|
||||
case VIEW_FAST_I64: { int64_t x; memcpy(&x, p, 8); return flan_dyn_from_i64(x); }
|
||||
case VIEW_FAST_F64: { double x; memcpy(&x, p, 8); return flan_dyn_from_f64(x); }
|
||||
case VIEW_FAST_BOOL: return flan_dyn_from_bool(*p ? 1 : 0);
|
||||
default: return view_read(loc, loclen, "at", o, o->u.view.desc, p);
|
||||
default: return view_read(loc, loclen, op, o, o->u.view.desc, p);
|
||||
}
|
||||
}
|
||||
}
|
||||
if (o->kind == OBJ_TEXT) {
|
||||
int64_t off;
|
||||
int w;
|
||||
if (k < 0 || k >= o->u.i) trap_range(loc, loclen, "at", v, k, o->u.i);
|
||||
if (k < 0 || k >= o->u.i) {
|
||||
if (soft) return flan_dyn_nil();
|
||||
trap_range(loc, loclen, op, v, k, o->u.i);
|
||||
}
|
||||
off = text_offset(o, k);
|
||||
return dyn_make(BOX_CHAR,
|
||||
utf8_decode(obj_text_bytes(o) + off, o->len - off, &w));
|
||||
}
|
||||
if (k < 0 || k >= o->len) trap_range(loc, loclen, "at", v, k, o->len);
|
||||
if (k < 0 || k >= o->len) {
|
||||
if (soft) return flan_dyn_nil();
|
||||
trap_range(loc, loclen, op, v, k, o->len);
|
||||
}
|
||||
return o->u.v.items[k];
|
||||
}
|
||||
|
||||
flan_dyn flan_dyn_at(flan_dyn v, flan_dyn i, const uint8_t *loc,
|
||||
int64_t loclen) {
|
||||
return at_core(v, i, loc, loclen, 0, "at");
|
||||
}
|
||||
|
||||
/* (slice s lo) and (slice s lo hi) over a text; nil for [hi] is the length.
|
||||
* The typed slice of a string is a view, and this is a copy: a text is
|
||||
* immutable, so no program can tell the two apart. A vec's slice would have
|
||||
@ -5165,6 +5183,18 @@ flan_dyn flan_dyn_get(flan_dyn m, flan_dyn k, const uint8_t *loc,
|
||||
return flan_dyn_map_get(m, k);
|
||||
}
|
||||
|
||||
/* The [get] builtin's, which [.field] does not share: over a map it is
|
||||
* [flan_dyn_get], and over a vec or a text it is [at] that answers nil for an
|
||||
* index out of range, negative included, where [at] traps. The index must
|
||||
* still be an int — a wrong kind of key is a mistake, not an absence. */
|
||||
flan_dyn flan_dyn_get_at(flan_dyn v, flan_dyn i, const uint8_t *loc,
|
||||
int64_t loclen) {
|
||||
/* Through [at]'s own body, so however [at] counts a text — by code point —
|
||||
* [get] counts the same. */
|
||||
if (!is_text(v) && !is_vec(v)) return flan_dyn_get(v, i, loc, loclen);
|
||||
return at_core(v, i, loc, loclen, 1, "get");
|
||||
}
|
||||
|
||||
static flan_dyn contains_walk(flan_dyn m, flan_dyn k) {
|
||||
flan_obj *o = want_map(walk_loc, walk_len, walk_op, m, k);
|
||||
if (o->kind == OBJ_VIEW) {
|
||||
|
||||
@ -270,6 +270,10 @@ flan_dyn flan_dyn_map_get(flan_dyn m, flan_dyn k);
|
||||
/* [get]'s, and a dyn's [.field]: [flan_dyn_map_get] with a site. */
|
||||
flan_dyn flan_dyn_get(flan_dyn m, flan_dyn k, const uint8_t *loc,
|
||||
int64_t loclen);
|
||||
/* The [get] builtin's: [flan_dyn_get] over a map, and over a vec or a text
|
||||
* the element, or nil for an index out of range. */
|
||||
flan_dyn flan_dyn_get_at(flan_dyn v, flan_dyn i, const uint8_t *loc,
|
||||
int64_t loclen);
|
||||
void flan_dyn_map_set(flan_dyn m, flan_dyn k, flan_dyn v);
|
||||
/* [put]'s: [flan_dyn_map_set], with the site a typed class slot's refusal
|
||||
* prints. */
|
||||
|
||||
@ -258,6 +258,19 @@ Each item: the proposal, then the reason in one line.
|
||||
line after a one-line `if c then a`, at its column, continues it (section
|
||||
3, item 6); each such clause is one-line (`elif c then x`, `else y`) or
|
||||
takes a block.
|
||||
- **`when c`** plus a block, or `when c then a`, reads as `when`, which is
|
||||
what an `if` without `else` reads as too. No `else` or `elif` follows it.
|
||||
A `when` whose value is kept (a `let`'s value, an argument, a return) gives
|
||||
`Some(a)` when `c` holds and `None` when it does not; where a `dyn` is
|
||||
wanted, `a` or `nil`. As a statement it gives nothing. An `if`/`elif` chain
|
||||
with no `else` is the same when kept: `None` when no test holds. **Built.**
|
||||
- **`if let P = v`** plus a block reads as `(if-let [P v] then)`; `elif` and
|
||||
`else` follow as for `if`, the rest of the chain being the `if-let`'s else.
|
||||
`elif let P = v` is a further `if-let` nested in that else.
|
||||
Kept with no `else` at the end of its chain, it gives an Option as `when` does.
|
||||
`P` is any `match` pattern, and its names are bound in the block only. One
|
||||
line: `if let Some(g) = o then g else 0`. A pattern that cannot fail, a
|
||||
plain name or `_`, is refused toward `let`. **Built.**
|
||||
- **`while c`, `until c`**, optional label first: `while :outer c`. **Built.**
|
||||
- **`for i in range(n)`**, `range(a, b)`, `range(a, b, step)` read as
|
||||
`dotimes`. `range` here is syntax, not a function. `..` is avoided because
|
||||
|
||||
68
test/programs/get-checked.flan
Normal file
68
test/programs/get-checked.flan
Normal file
@ -0,0 +1,68 @@
|
||||
;;;; get over an array, a slice, a string and a Vec is at that answers None
|
||||
;;;; for an index out of range, negative included, one index per dimension.
|
||||
;;;; Over a dyn it answers nil, and more keys walk a level each.
|
||||
|
||||
(defn show [o (Option i32)] ()
|
||||
(match o (Some v) (println v) None (println "none")))
|
||||
|
||||
(defn three [] (Vec i32)
|
||||
(let [v (vec-new i32)] (push v 10) (push v 20) (push v 30) v))
|
||||
|
||||
(defn dvec [] dyn [10 [20 21] 30])
|
||||
(defn dmap [] dyn {:a 1 :b [5 6]})
|
||||
(defn dtext [] dyn "héy")
|
||||
|
||||
(defn main [] ()
|
||||
(let [a [1 2 3]
|
||||
grid [[1 2 3] [4 5 6]]
|
||||
s (slice a)
|
||||
v (three)
|
||||
n (length a)
|
||||
vv (vec-new (Vec i32) context/temp)]
|
||||
(push vv v)
|
||||
;; -1, 0, len-1 and len on an array.
|
||||
(show (get a -1))
|
||||
(show (get a 0))
|
||||
(show (get a (- n 1)))
|
||||
(show (get a n))
|
||||
;; Two dimensions, each tested.
|
||||
(let [r 0 c 1]
|
||||
(show (get grid (+ r 1) (- c 1)))
|
||||
(show (get grid (- r 1) c))
|
||||
(show (get grid r (+ c 2))))
|
||||
(show (get grid 1 2))
|
||||
(show (get grid 2 0))
|
||||
;; A slice.
|
||||
(show (get s 2))
|
||||
(show (get s 3))
|
||||
;; A Vec, and one a call answered.
|
||||
(show (get v -1))
|
||||
(show (get v 0))
|
||||
(show (get v 2))
|
||||
(show (get v 3))
|
||||
(show (get (three) 1))
|
||||
;; A Vec of Vecs: the inner length is tested only once the outer index is.
|
||||
(show (get vv 0 2))
|
||||
(show (get vv 0 3))
|
||||
(show (get vv 1 0))
|
||||
;; A string's byte.
|
||||
(match (get "hey" 1) (Some b) (println b) None (println "none"))
|
||||
(match (get "hey" 3) (Some b) (println b) None (println "none")))
|
||||
;; Dyn.
|
||||
(let [d (dvec) m (dmap)]
|
||||
(println (get d -1))
|
||||
(println (get d 0))
|
||||
(println (get d 2))
|
||||
(println (get d 3))
|
||||
(println (get d 1 1))
|
||||
(println (get d 1 2))
|
||||
(println (get d 5 0))
|
||||
(println (get m :a))
|
||||
(println (get m :z))
|
||||
(println (get m :b 1))
|
||||
(println (get m :z 1))
|
||||
(println (.a m))
|
||||
;; Dyn text: get counts it as at does, by character.
|
||||
(println (get (dtext) 1))
|
||||
(println (get (dtext) 2))
|
||||
(println (get (dtext) 3))))
|
||||
5
test/programs/get-trap.flan
Normal file
5
test/programs/get-trap.flan
Normal file
@ -0,0 +1,5 @@
|
||||
;;;; A dyn get with an index that is not an int traps, in get's own words:
|
||||
;;;; the message names get and shows the get call, not at.
|
||||
|
||||
(defn main [] ()
|
||||
(println (get (the dyn "héllo") 1.5)))
|
||||
47
test/programs/if-let-kept.fln
Normal file
47
test/programs/if-let-kept.fln
Normal file
@ -0,0 +1,47 @@
|
||||
;; A kept if let with no else at the end of its chain gives an Option: Some of
|
||||
;; the arm that ran, None when none did.
|
||||
|
||||
fn pick(a: Option(i32), k: i32) -> Option(i32)
|
||||
if let Some(x) = a then x
|
||||
elif k > 0 then k
|
||||
|
||||
fn only(a: Option(i32)) -> Option(i32)
|
||||
if let Some(x) = a then x * 2
|
||||
|
||||
fn lead(k: i32, b: Option(i32)) -> Option(i32)
|
||||
if k > 5
|
||||
k
|
||||
elif let Some(y) = b
|
||||
y
|
||||
|
||||
;; An arm that returns stays Never, and the rest of the chain decides.
|
||||
fn early(a: Option(i32)) -> Option(i32)
|
||||
if let Some(x) = a
|
||||
return None
|
||||
elif true
|
||||
3
|
||||
|
||||
fn dyn_only(a: Option(i32)) -> dyn
|
||||
if let Some(x) = a then x
|
||||
|
||||
fn show(o: Option(i32))
|
||||
match o
|
||||
Some(v) -> println(v)
|
||||
None -> println("none")
|
||||
|
||||
fn main()
|
||||
show(pick(Some(1), 0))
|
||||
show(pick(None, 4))
|
||||
show(pick(None, 0))
|
||||
show(only(Some(3)))
|
||||
show(only(None))
|
||||
show(lead(9, None))
|
||||
show(lead(1, Some(2)))
|
||||
show(lead(1, None))
|
||||
show(early(None))
|
||||
show(early(Some(1)))
|
||||
println(dyn_only(Some(5)))
|
||||
println(dyn_only(None))
|
||||
;; As a statement it is unchanged.
|
||||
if let Some(x) = Some(7)
|
||||
println(x)
|
||||
71
test/programs/if-let.fln
Normal file
71
test/programs/if-let.fln
Normal file
@ -0,0 +1,71 @@
|
||||
;; if let: the block runs when the pattern matches, its names bound there only.
|
||||
|
||||
data Shape
|
||||
Rect(w: i32, h: i32)
|
||||
Dot
|
||||
|
||||
enum Dir
|
||||
north = 0
|
||||
south = 1
|
||||
|
||||
fn describe(o: Option(i32), k: i32) -> i32
|
||||
if let Some(g) = o
|
||||
g + 1
|
||||
elif k > 5
|
||||
100
|
||||
else
|
||||
0
|
||||
|
||||
fn first(xs: [3 i32]) -> i32
|
||||
if let Some(x) = get(xs, 0) then x else -1
|
||||
|
||||
;; elif let: the rest of the chain is the else of an if let.
|
||||
fn pick(a: Option(i32), b: Option(i32), k: i32) -> i32
|
||||
if let Some(x) = a
|
||||
x
|
||||
elif let Some(y) = b
|
||||
y * 10
|
||||
elif k > 5
|
||||
100
|
||||
else
|
||||
0
|
||||
|
||||
;; Nested: a pattern tested inside the block of another.
|
||||
fn area(s: Option(Shape)) -> i32
|
||||
if let Some(x) = s
|
||||
if let Rect(w, h) = x
|
||||
w * h
|
||||
else
|
||||
-1
|
||||
else
|
||||
-2
|
||||
|
||||
fn main()
|
||||
let g = 7
|
||||
println(describe(Some(4), 0))
|
||||
println(describe(None, 9))
|
||||
println(describe(None, 1))
|
||||
println(first([9, 8, 7]))
|
||||
println(pick(Some(1), None, 0))
|
||||
println(pick(None, Some(2), 0))
|
||||
println(pick(None, None, 9))
|
||||
println(pick(None, None, 1))
|
||||
;; Shadowing: g is the payload inside the block and the outer g after it.
|
||||
if let Some(g) = Some(1)
|
||||
println(g)
|
||||
println(g)
|
||||
;; Any match pattern.
|
||||
if let None = get([1, 2], 5)
|
||||
println("absent")
|
||||
if let :north = Dir.north
|
||||
println("north")
|
||||
println(area(Some(Shape.Rect{.w 2 .h 3})))
|
||||
println(area(Some(Shape.Dot)))
|
||||
println(area(None))
|
||||
;; when on one line and with a block.
|
||||
let w = when g > 3 then g * 2
|
||||
match w
|
||||
Some(v) -> println(v)
|
||||
None -> println("none")
|
||||
when g > 1
|
||||
println("when block")
|
||||
63
test/programs/when-value.flan
Normal file
63
test/programs/when-value.flan
Normal file
@ -0,0 +1,63 @@
|
||||
;;;; A when whose value is kept answers an Option: Some of its body when the
|
||||
;;;; test holds, None when it does not. As a statement it answers nothing.
|
||||
;;;; Where a dyn is wanted it answers the body or nil, since dyn has no
|
||||
;;;; Option. A body that is already an Option is not flattened.
|
||||
|
||||
(defn show [o (Option i32)] ()
|
||||
(match o (Some v) (println v) None (println "none")))
|
||||
|
||||
;; Returned: the return type is the want.
|
||||
(defn half [n i32] (Option i32) (when (= 0 (% n 2)) (/ n 2)))
|
||||
|
||||
;; Nested, as Rust's bool::then: None from the body stays apart from a
|
||||
;; failed test.
|
||||
(defn wrap [c bool o (Option i32)] (Option (Option i32)) (when c o))
|
||||
|
||||
(defn level [oo (Option (Option i32))] ()
|
||||
(match oo
|
||||
(Some o) (match o (Some v) (println v) None (println "some none"))
|
||||
None (println "none")))
|
||||
|
||||
;; Dyn: the body or nil.
|
||||
(defn dyn-when [x] dyn (when x 5))
|
||||
|
||||
;; An if-let arm that returns stays Never; the when after it decides.
|
||||
(defn early [a (Option i32)] (Option i32)
|
||||
(if-let [(Some x) a] (return None) (when true 3)))
|
||||
|
||||
;; A lambda's last form is kept at the return type its position wants.
|
||||
(defn call-it [f (Fn [] (Option i32))] () (show (f)))
|
||||
|
||||
;; A kept cond with no :else is a when over several tests.
|
||||
(defn pick [n i32] (Option i32) (cond (= n 1) 10 (= n 2) 20))
|
||||
(defn dpick [n] dyn (cond (= n 1) "a" (= n 2) "b"))
|
||||
|
||||
(defn main [] ()
|
||||
(show (half 10))
|
||||
(show (half 7))
|
||||
;; A let's value.
|
||||
(let [a (when (> 3 2) 42)
|
||||
b (when (> 2 3) 42)]
|
||||
(show a)
|
||||
(show b))
|
||||
;; An argument.
|
||||
(show (when true 9))
|
||||
(level (wrap true (Some 1)))
|
||||
(level (wrap true None))
|
||||
(level (wrap false (Some 1)))
|
||||
(println (dyn-when true))
|
||||
(println (dyn-when nil))
|
||||
(show (early None))
|
||||
(show (early (Some 1)))
|
||||
(call-it (fn [] (when true 6)))
|
||||
(call-it (fn [] (when false 6)))
|
||||
(show (pick 2))
|
||||
(show (pick 3))
|
||||
(let [k (cond (> 3 5) 1 (> 3 2) 2)] (show k))
|
||||
(println (dpick 1))
|
||||
(println (dpick 9))
|
||||
(cond (> 3 5) (println "no") (> 3 2) (println "cond stmt"))
|
||||
;; Statements, unchanged.
|
||||
(when true (println "ran"))
|
||||
(when false (println "not run"))
|
||||
(println "end"))
|
||||
@ -2224,6 +2224,46 @@ let () =
|
||||
dyn_if_truthy_out;
|
||||
outputs ~x86:true "dyn if truthiness, --x86" "programs/dyn-if-truthy.flan"
|
||||
dyn_if_truthy_out;
|
||||
(* A kept when is an Option; get is a checked lookup; if let. *)
|
||||
let when_value_out =
|
||||
"5\nnone\n42\nnone\n9\n1\nsome none\nnone\n5\nnil\n3\nnone\n6\nnone\n20\nnone\n2\n\
|
||||
a\nnil\ncond stmt\nran\nend\n"
|
||||
in
|
||||
outputs "when as a value" "programs/when-value.flan" when_value_out;
|
||||
outputs ~opt:"-O0" "when as a value, -O0" "programs/when-value.flan" when_value_out;
|
||||
outputs ~x86:true "when as a value, --x86" "programs/when-value.flan" when_value_out;
|
||||
let get_checked_out =
|
||||
"none\n1\n3\nnone\n4\nnone\nnone\n6\nnone\n3\nnone\n\
|
||||
none\n10\n30\nnone\n20\n30\nnone\nnone\n101\nnone\n\
|
||||
nil\n10\n30\nnil\n21\nnil\nnil\n1\nnil\n6\nnil\n1\n\\\u{e9}\n\\y\nnil\n"
|
||||
in
|
||||
outputs "get as a checked lookup" "programs/get-checked.flan" get_checked_out;
|
||||
outputs ~opt:"-O0" "get as a checked lookup, -O0" "programs/get-checked.flan"
|
||||
get_checked_out;
|
||||
outputs ~x86:true "get as a checked lookup, --x86" "programs/get-checked.flan"
|
||||
get_checked_out;
|
||||
let if_let_out =
|
||||
"5\n100\n0\n9\n1\n20\n100\n0\n1\n7\nabsent\nnorth\n6\n-1\n-2\n14\nwhen block\n"
|
||||
in
|
||||
let if_let_kept_out =
|
||||
"1\n4\nnone\n6\nnone\n9\n2\nnone\n3\nnone\n5\nnil\n7\n"
|
||||
in
|
||||
outputs "a kept if let chain" "programs/if-let-kept.fln" if_let_kept_out;
|
||||
outputs ~opt:"-O0" "a kept if let chain, -O0" "programs/if-let-kept.fln" if_let_kept_out;
|
||||
outputs ~x86:true "a kept if let chain, --x86" "programs/if-let-kept.fln" if_let_kept_out;
|
||||
outputs "if let" "programs/if-let.fln" if_let_out;
|
||||
(let exe = compile "programs/get-trap.flan" in
|
||||
let code, text = run exe None in
|
||||
if code <> 134 || not (contains text "dyn get:")
|
||||
|| not (contains text "(get \"h\195\169llo\" 1.5)")
|
||||
then begin
|
||||
incr failures;
|
||||
Printf.printf "FAIL a dyn get's trap names get\n got: %S (exit %d)\n"
|
||||
text code
|
||||
end;
|
||||
(try Sys.remove exe with Sys_error _ -> ()));
|
||||
outputs ~opt:"-O0" "if let, -O0" "programs/if-let.fln" if_let_out;
|
||||
outputs ~x86:true "if let, --x86" "programs/if-let.fln" if_let_out;
|
||||
(* format-f64, the first number formatter a caller can steer. The three
|
||||
lines that would ship wrong are pinned deliberately: 0.999995 at five
|
||||
places, where the rounded fraction equals the scale and is the next
|
||||
|
||||
@ -3975,7 +3975,7 @@ let () =
|
||||
rejects_check "an inline generator's body has to answer the element type"
|
||||
"(defonce grid [2 [3 u8]] (array-gen [2 3] (fn [i j] 1.5)))\n\
|
||||
(defn f [] i32 0)"
|
||||
~needle:"expected u8, found f64";
|
||||
~needle:"expected u8, found the float literal 1.5";
|
||||
rejects_check "an inline generator takes one argument per dimension too"
|
||||
"(defn f [] i32 (let [a (array-gen [2] (fn [i j] i))] 0))"
|
||||
~needle:"this array-gen has 1 dimension, so its generator is called with \
|
||||
@ -8322,5 +8322,52 @@ let () =
|
||||
parse_rejects "_ in a defgeneric's return slot"
|
||||
~needle:"defgeneric's methods each have their own"
|
||||
"(defgeneric area [s] _)";
|
||||
(* if-let refuses a pattern that cannot fail, toward let; the program half
|
||||
is programs/if-let.flan. *)
|
||||
rejects_check "if-let over a plain name"
|
||||
~needle:"the pattern g is a plain name, which always matches"
|
||||
"(defn main [] () (if-let [g (Some 1)] (println g)))";
|
||||
rejects_check "and says let" ~needle:"(let [g ...] ...)"
|
||||
"(defn main [] () (if-let [g (Some 1)] (println g)))";
|
||||
rejects_check "if-let over _" ~needle:"the pattern _ always matches"
|
||||
"(defn main [] () (if-let [_ (Some 1)] (println 1)))";
|
||||
accepts "if-let over a case with no fields"
|
||||
"(defdata S [(A []) (B [])])\n(defn main [] () (if-let [A S.B] (println 1)))";
|
||||
(* A used when is an Option, and a statement's is nothing. *)
|
||||
accepts "a let's when is an Option"
|
||||
"(defn main [] () (let [x (the (Option i32) (when true 1))] (println x)))";
|
||||
rejects_check "a when is not its branch's type" ~needle:"(Option i32)"
|
||||
"(defn f [] i32 (when true 1))\n(defn main [] ())";
|
||||
rejects_check "a when as an operand is blamed, not the literal beside it"
|
||||
~needle:"this when is an operand of +, so its value is kept"
|
||||
"(defn main [] () (println (+ 1 (when true 5))))";
|
||||
rejects_check "on either side"
|
||||
~needle:"this when is an operand of +, so its value is kept"
|
||||
"(defn main [] () (println (+ (when true 5) 1)))";
|
||||
(* Any form with no else at its end, beside a number, is blamed itself. *)
|
||||
List.iter
|
||||
(fun (what, e, needle) ->
|
||||
rejects_check ("a kept " ^ what ^ " beside a number is blamed itself")
|
||||
~needle
|
||||
("(defn main [] () (let [c true] (println " ^ e ^ ")))"))
|
||||
[ ("when in <", "(< 1 (when c 5))", "this when is an operand of <, so its value is kept");
|
||||
("when in =", "(= 1 (when c 5))", "this when is an operand of =, so its value is kept");
|
||||
("cond", "(+ 1 (cond c 5))", "this chain without an else is an operand of +");
|
||||
("if ending in a when", "(+ 1 (if c 5 (when c 6)))",
|
||||
"this chain without an else is an operand of +");
|
||||
("do ending in a when", "(+ 1 (do (when c 5)))", "this when is an operand of +");
|
||||
("if-let", "(+ 1 (if-let [(Some x) (Some c)] 5))",
|
||||
"this if let without an else is an operand of +") ];
|
||||
(* get on a String is refused as at is. *)
|
||||
rejects_check "get on a String is refused as at is"
|
||||
~needle:"a String is not indexed"
|
||||
"(defn main [] () (let [s (string-new \"abc\")] (println (get s 1))))";
|
||||
accepts "a lambda's when takes the Option its position wants"
|
||||
"(defn call-it [f (Fn [] (Option i32))] () (println (f)))\n\
|
||||
(defn main [] () (call-it (fn [] (when true 6))))";
|
||||
accepts "a kept cond with no :else is an Option"
|
||||
"(defn f [n i32] (Option i32) (cond (= n 1) 10 (= n 2) 20))\n(defn main [] ())";
|
||||
rejects_check "a map's get takes one key" ~needle:"a map's get takes one key"
|
||||
"(defn main [] () (let [m (map-new i32 i32)] (println (get m 1 2))))";
|
||||
|
||||
Test_support.report ()
|
||||
|
||||
@ -1138,6 +1138,40 @@ let () =
|
||||
" sort-by(xs, fn(a, b) =>\n g(a)\n a < b)";
|
||||
round "one closer for a call in a call"
|
||||
"(defn f [] () (println (run (fn [] (g) 1))))" " println(run(fn() =>\n g()\n 1))";
|
||||
(* if let and when, read both ways and printed back. *)
|
||||
round "if let with a block and an else"
|
||||
"(defn f [o (Option i32)] i32 (if-let [(Some g) o] (do (println g) g) 0))"
|
||||
" if let Some(g) = o\n println(g)\n g\n else\n 0";
|
||||
round "if let on one line"
|
||||
"(defn f [o (Option i32)] i32 (if-let [(Some g) o] g 0))"
|
||||
" if let Some(g) = o then g else 0";
|
||||
round "if let with elif"
|
||||
"(defn f [o (Option i32) k i32] i32 (if-let [(Some g) o] (+ g 1) (cond (> k 5) 100 :else 0)))"
|
||||
" elif k > 5\n 100\n else\n 0";
|
||||
round "if let with no else" "(defn f [o (Option i32)] () (if-let [(Some g) o] (do (println g) (println g))))"
|
||||
" if let Some(g) = o\n println(g)";
|
||||
round "elif let"
|
||||
"(defn f [a (Option i32) b (Option i32) k i32] i32 \
|
||||
(if-let [(Some x) a] x (if-let [(Some y) b] (* y 10) (if (> k 5) 100 0))))"
|
||||
" elif let Some(y) = b\n y * 10\n elif k > 5\n 100\n else\n 0";
|
||||
round "elif let after a plain if"
|
||||
"(defn f [a bool b (Option i32)] () \
|
||||
(if a (println 1) (if-let [(Some y) b] (println y) (when (> 1 0) (println 2)))))"
|
||||
" elif let Some(y) = b\n println(y)\n elif 1 > 0\n println(2)";
|
||||
reads "elif let reads as a nested if-let"
|
||||
"if let Some(x) = a\n f(x)\nelif let None = b\n g()\nelse\n h()"
|
||||
"(if-let [(Some x) a] (f x) (if-let [None b] (g) (h)))";
|
||||
round "a kept if let chain with no else"
|
||||
"(defn f [a (Option i32) k i32] (Option i32) (if-let [(Some x) a] (do (g) x) (cond (> k 0) k)))"
|
||||
" if let Some(x) = a\n g()\n x\n elif k > 0\n k";
|
||||
round "a kept when" "(defn f [] () (let [w (when (> a 1) 2)] (g w)))"
|
||||
" let w = when a > 1 then 2";
|
||||
reads "when with a block" "when a\n b()\n c()" "(when a (b) (c))";
|
||||
reads "when on one line" "when a then b()" "(when a (b))";
|
||||
reads "if let with elif and no else" "if let None = o\n a()\nelif c\n b()"
|
||||
"(if-let [None o] (a) (cond c (b)))";
|
||||
refuses "when has no else" "when a then b() else c()" "indent/when-else" "a when has no else";
|
||||
refuses "nor an else block" "when a\n b()\nelse\n c()" "indent/when-else" "a when has no else";
|
||||
round "a typed block lambda in a call"
|
||||
"(defn f [] () (h (the (Fn [C] bool) (fn [c] (g c) (> (.n c) 3)))))"
|
||||
" h(fn(c: C) -> bool =>\n g(c)\n c.n > 3)";
|
||||
@ -1349,6 +1383,24 @@ let checks name text =
|
||||
| _ -> ()
|
||||
| exception e -> fail "%s does not check: %s" name (diag_text e)
|
||||
|
||||
(* A kept if-let chain whose arm gives no value is a statement, refused as a
|
||||
plain if's is; one whose arm returns stays Never, in both syntaxes. *)
|
||||
let () =
|
||||
refused "if-let-unit.flan"
|
||||
"(defn main [] () (let [a (Some 1) r (if-let [(Some x) a] (println x) \
|
||||
(when true (println 2)))] (println r)))\n"
|
||||
[ "r would be bound to (), which is not a value" ];
|
||||
refused "if-let-unit.fln"
|
||||
"fn main()\n let a = Some(1)\n let r = if let Some(x) = a then println(x) \
|
||||
else when true then println(2)\n println(r)\n"
|
||||
[ "r would be bound to (), which is not a value" ];
|
||||
checks "if-let-never.flan"
|
||||
"(defn f [a (Option i32)] (Option i32) (if-let [(Some x) a] (return None) \
|
||||
(when true 3)))\n(defn main [] () (println (f None)))\n";
|
||||
checks "if-let-never.fln"
|
||||
"fn f(a: Option(i32)) -> Option(i32)\n if let Some(x) = a\n return None\n \
|
||||
elif true\n 3\n\nfn main()\n println(f(None))\n"
|
||||
|
||||
let () =
|
||||
let poke_fln = "fn poke(coll) -> dyn\n coll[0] = 99\n coll\n\n" in
|
||||
let poke_flan = "(defn poke [coll] dyn (set (at coll 0) 99) coll)\n" in
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user