Joseph Ferano
d6fc15474b
The author: "I think I prefer length over len, because then I'll use len as the variable name". One arm in check.ml, one row in the table beside it, and every (len x) in lib, test, examples, vendor, spike, docs, web, emacs, plan.org and NEXT.md rewritten. Shadowing and builtin/ had already taken most of the sting out: a (defn len ...) was legal and won in its own file, and builtin/len reached past it. What was left is that len was still a builtin — the defn earned a warning, and a wrapper had to say builtin/ at every inner call. Now there is nothing under the short name: len is an ordinary identifier in every position, which is what (let [len (length xs)] ...) wants. length takes over as shadowing's worked example rather than the feature losing one. shadow-builtin.flan, builtin-qualified.flan, pkgs/shadowed and the builtin/ rows in test_flan move to it and go on testing shadowing. A call to a len nothing defines is answered where an unknown function is, after every table and after the shadowing guard, so a program with its own len never reaches it. The sentence is said rather than guessed at — len and length are three edits apart and the did-you-mean's net is one — and the call is written back out through spell_arg, as-slice's spelling lifted out of it and now shared, so what is printed compiles. sand.flan:33 still calls the old name and is the author's to change; until it does, test_acceptance and test_session abort there. Both were run green against a copy with that one line changed. FIX.org says so.
155 lines
6.7 KiB
Plaintext
155 lines
6.7 KiB
Plaintext
;;;; The prelude's second tier: the functions that return new storage.
|
|
;;;;
|
|
;;;; Every one of these was refused by name in prelude.ml until there was an
|
|
;;;; allocator to return a Vec from, and this file is the corpus that says the
|
|
;;;; refusals are lifted. The cases are chosen the way the slice-algorithm
|
|
;;;; tests were: each is an input a plausible wrong version gets wrong.
|
|
;;;;
|
|
;;;; Everything allocated here is freed, even though leaking is defined
|
|
;;;; behaviour (spec-memory.md), because this file is the example people copy.
|
|
|
|
;;; A (Vec u8) printed as text, without the caller writing the two-step every
|
|
;;; time. slice borrows -- it copies ptr+len and never the elements -- so v
|
|
;;; is still the owner afterwards and is still free-able.
|
|
(defn show [v (Ptr (Vec u8))] ()
|
|
(println (string (slice (deref v)))))
|
|
|
|
(defn main [] i32
|
|
;; The builder. Three appends and two numbers into one Vec, which is the
|
|
;; case the shared static scratch buffer in the runtime makes impossible for
|
|
;; i64->bytes on its own: two of its results cannot be held at once, and
|
|
;; these two numbers are both in the answer.
|
|
(let [b (vec-new u8)]
|
|
(append (addr b) (bytes-view "x="))
|
|
(append-i64 (addr b) 42)
|
|
(append (addr b) (bytes-view " y="))
|
|
(append-i64 (addr b) -7)
|
|
(append (addr b) (bytes-view " r="))
|
|
(append-f64 (addr b) 1.5)
|
|
(show (addr b)) ; x=42 y=-7 r=1.5
|
|
(free b))
|
|
|
|
;; concat over three parts, and over none -- the empty result rather than a
|
|
;; trap.
|
|
(let [parts [(bytes-view "one") (bytes-view "") (bytes-view "two")]]
|
|
(let [c (concat (slice parts 0 3))]
|
|
(show (addr c)) ; onetwo
|
|
(free c)))
|
|
(let [parts [(bytes-view "unused")]]
|
|
(let [c (concat (slice parts 0 0))]
|
|
(println (length c)) ; 0
|
|
(free c)))
|
|
|
|
;; join: n parts, n-1 separators. The one-part case is the one that must not
|
|
;; emit a separator at all, and the zero-part case is the one a "append then
|
|
;; chop the tail" join gets wrong because there is no tail.
|
|
(let [parts [(bytes-view "a") (bytes-view "b") (bytes-view "c")]]
|
|
(let [j (join (slice parts 0 3) (bytes-view ", "))]
|
|
(show (addr j)) ; a, b, c
|
|
(free j))
|
|
(let [j (join (slice parts 0 1) (bytes-view ", "))]
|
|
(show (addr j)) ; a
|
|
(free j))
|
|
(let [j (join (slice parts 0 0) (bytes-view ", "))]
|
|
(println (length j)) ; 0
|
|
(free j))
|
|
;; An empty separator is concat.
|
|
(let [j (join (slice parts 0 3) (bytes-view ""))]
|
|
(show (addr j)) ; abc
|
|
(free j)))
|
|
|
|
;; repeat, including zero times.
|
|
(let [r (repeat-bytes (bytes-view "ab") 3)]
|
|
(show (addr r)) ; ababab
|
|
(free r))
|
|
(let [r (repeat-bytes (bytes-view "ab") 0)]
|
|
(println (length r)) ; 0
|
|
(free r))
|
|
|
|
;; The allocating case pair. The input is a string literal, which lives in
|
|
;; .rodata -- an in-place lower would either segfault at -O0 or be deleted at
|
|
;; -O2, and that is exactly why these exist. Digits and punctuation pass
|
|
;; through untouched, which is the range check a table-free version gets
|
|
;; wrong by shifting every byte.
|
|
(let [l (to-lower (bytes-view "Hello, World 42!"))]
|
|
(show (addr l)) ; hello, world 42!
|
|
(free l))
|
|
(let [u (to-upper (bytes-view "Hello, World 42!"))]
|
|
(show (addr u)) ; HELLO, WORLD 42!
|
|
(free u))
|
|
|
|
;; replace. "aaa" with "aa" -> "b" is the non-overlapping rule: the answer is
|
|
;; "ba", because the match consumes both a's and the scan resumes after them.
|
|
(let [r (replace-bytes (bytes-view "aaa") (bytes-view "aa") (bytes-view "b"))]
|
|
(show (addr r)) ; ba
|
|
(free r))
|
|
;; A replacement longer than what it replaces, and one that is empty.
|
|
(let [r (replace-bytes (bytes-view "a,b,c") (bytes-view ",") (bytes-view " -- "))]
|
|
(show (addr r)) ; a -- b -- c
|
|
(free r))
|
|
(let [r (replace-bytes (bytes-view "a,b,c") (bytes-view ",") (bytes-view ""))]
|
|
(show (addr r)) ; abc
|
|
(free r))
|
|
;; No occurrence is a copy, and an empty `from` is a copy -- the reading
|
|
;; where it matches everywhere is an infinite loop.
|
|
(let [r (replace-bytes (bytes-view "abc") (bytes-view "z") (bytes-view "!"))]
|
|
(show (addr r)) ; abc
|
|
(free r))
|
|
(let [r (replace-bytes (bytes-view "abc") (bytes-view "") (bytes-view "!"))]
|
|
(show (addr r)) ; abc
|
|
(free r))
|
|
|
|
;; split. n separators, n+1 fields, always -- so the trailing empty field is
|
|
;; present, which is where Odin's own iterator and its allocating split
|
|
;; disagree with each other.
|
|
(let [f (split (bytes-view "a,b,c") \,)]
|
|
(println (length f)) ; 3
|
|
(println (string (at f 0))) ; a
|
|
(println (string (at f 2))) ; c
|
|
(free f))
|
|
(let [f (split (bytes-view "a,b,") \,)]
|
|
(println (length f)) ; 3
|
|
(println (length (at f 2))) ; 0
|
|
(free f))
|
|
(let [f (split (bytes-view ",a") \,)]
|
|
(println (length f)) ; 2
|
|
(println (length (at f 0))) ; 0
|
|
(free f))
|
|
;; No separator at all is one field, and the empty input is one empty field.
|
|
(let [f (split (bytes-view "abc") \,)]
|
|
(println (length f)) ; 1
|
|
(println (string (at f 0))) ; abc
|
|
(free f))
|
|
(let [f (split (bytes-view "") \,)]
|
|
(println (length f)) ; 1
|
|
(println (length (at f 0))) ; 0
|
|
(free f))
|
|
|
|
;; The fields are slices of the input and nothing was copied: this one
|
|
;; round-trips through join, and the separator it rebuilds with is a
|
|
;; different one, so an implementation that handed back the original slice
|
|
;; would print the original string.
|
|
(let [f (split (bytes-view "a,b,c") \,)]
|
|
(let [j (join (slice f) (bytes-view "/"))]
|
|
(show (addr j)) ; a/b/c
|
|
(free j))
|
|
(free f))
|
|
|
|
;; The allocator is the context's, so with-allocator moves the whole tier
|
|
;; into an arena -- which is the answer to the fixed arity of a defn, and the
|
|
;; reason none of these takes an allocator argument. free-all is what
|
|
;; releases the region, and arena-destroy hands it back.
|
|
(let [a (arena-new 4096)]
|
|
(with-allocator a
|
|
(let [parts [(bytes-view "in") (bytes-view "arena")]]
|
|
(let [j (join (slice parts 0 2) (bytes-view "-"))]
|
|
(show (addr j)) ; in-arena
|
|
;; The free is written because the binding is dead after it either
|
|
;; way, and it keeps the block: an arena cannot release one, which
|
|
;; is the difference the capability set exists to state. free-all
|
|
;; below is what actually releases this.
|
|
(free j))))
|
|
(free-all a)
|
|
(arena-destroy a))
|
|
0)
|