(array-gen [3 4] (fn [i j] ...)) — the canonical form — was refused:
check_fn saw no (Fn ...) want and no position to take types from. But the
form knows them: one i32 index per dimension is the rank's own promise.
check_array_gen now hands an inline fn its parameter types directly, with
the annotated element type as the return want where the annotation reaches
that deep, and the return left for the body to say where it does not — so
a bare inline fn infers its element type the way a fill value does, and a
body that disagrees with an annotated element is reported at the
generator's answer, per element. Named defn generators check as before.
check_fn grows a ?gen way in for exactly this: parameter types without a
Fn want, return optional. An inferred-return body sees Unit as ctx.ret, a
rough edge left rough on purpose.
Pins: inline at rank 1 and 2, inferred element, annotated defvar, the
per-element mismatch, inline arity. The acceptance program gains the
inline form, a struct-valued fill (the per-element store is a struct
copy), and evaluated-once (a counting fill value called one time for four
elements) — riding the three existing rows, no new ones. And the FIX.org
entry the pass never wrote: dims by the [n T] rule, one index per
dimension, the Zero+While/Set/Pindex lowering with no backend edits,
composition by nesting the forms, and this fix.
The two compositions the milestone owed, pinned, and the record of the
whole lane.
A package whose exports are generic: pkgs/gen, imported by
pkg-generic.flan at three shapes. One generic at two element types.
One that calls another in its own package at its own variable, so the
transitive copy is generated from a call site two files away. And a
generic written in the program calling one written in the package at
its own $t, which only resolves once Load has flattened both bodies
into one namespace -- the thing that has to change the day a package
becomes a real compilation unit, because a copy is made from a body
and a body that did not cross cannot be copied. Plus the call-site
half of a bound written in another file, quoted here rather than
pointed at in a file the caller cannot change.
And the composition with the widening trial. A binary operator
re-checks its right operand at its left one's type inside a trial, so
a generic call written there is checked twice and once thrown away.
The discarded pass's instantiation does not go back out: instantiate
rewinds a copy whose *body* refused, which is a different event. It
does not have to, and the reason is this lane's own rule rather than
luck -- a generic call's instantiation is read off its arguments and
never off the ambient want, so both passes ask for the same types and
the second ask is a cache hit. Pinned by counting the copies in the
checked program.
The widening lane's note said that cache already rewinds itself. It
does not. Corrected in the comment and in FIX.org, in place.
The refusals generics obsoleted, swept. Every message that sent
somebody to a schedule now says what is actually true of the thing in
front of them.
An unknown lowercase type name used to be reported as unimplemented
generic code over a type variable. Generics are implemented, and
resolve_name consults env.tyvars and env.subst long before anything
reaches that arm -- so a lowercase name arriving there is a typo too
far from any type to guess at, or a type variable nobody introduced.
The sentence names the sigil that would introduce it.
A capitalised name given type arguments is the other half, and it is
still genuinely unbuilt: Types.Named is a bare string with no room for
parameters, and giving it some is a change to Types.t and therefore to
the layout calculator, both backends, Render and DWARF. Both sites
that reported it -- the type resolver and the value-position fork --
now say a generic *type* is not there yet and point at the generic
function that is.
Plus the prelude's side of it. pos?, neg? and zero? are three
questions about a number's sign, one body each, answering at every
numeric type -- the family the whole feature was asked for, and the
one thing the landed generics could not write until a literal was
allowed to stand at a bounded type variable.
Two collapses examined and declined, with the real reason written
where the old one was. abs stays per width because numeric? is the
only bound that admits a written 0 and it admits floats too, and the
integer body is the wrong abs for a float: it hands back a negative
zero. It waits on an integer? predicate, which is language surface.
min and max stay builtins because they are variadic and slot each
operand so it is evaluated once; a binary prelude generic would put
the double evaluation back at the call site. Their generic half was
never missing -- ordered? already admits them in any body that
declares it.
Nothing stopped a type variable being instantiated at dyn, because dyn
is an ordinary case of Types.t and substituted like any other type. The
copy was then made and walked into the dyn answers that are not all
there, and the refusal arrived from inside the generic's own source:
(or-else (Some d) e) over two dyns was reported against <prelude>:385,
a line the caller did not write and cannot act on.
Refused at the binding instead, where the call site is. The message
does not only say no: two models answer "one body, many types" here
and they are not rivals -- this one copies per written type at compile
time, defgeneric/defmethod dispatch at run time on a value that
carries its own -- so a dyn argument is asking the second question of
the first machinery, and the sentence names the other spelling.
Only the unbounded half is new. A variable carrying a {:where} clause
was already refused, because pred_holds says no to dyn for all four
predicates, and that refusal is left in front of this one on purpose:
it names the predicate the signature wrote down, which is the more
specific of the two answers.
Whether dyn should eventually flow through a generic is the author's
call and is recorded as open. Refusing now is the direction that can
be walked back: allowing it later adds programs, and nothing written
under this rule stops compiling.
Implicit widening landed after generics did, and the rule the two of
them left between them read off the order the arguments were written
in. (eq2? i8 i64) was refused, because $t bound to i8 and i64 into i8
can lose. (eq2? i64 i8) was accepted, because $t had already bound to
i64 and the i8 widened into the want that substitution had made
concrete. Same two values, same function, one copy at i8 refused and
one copy at i64 generated.
Neither answer was unsound -- a widen cannot change a number -- so
this is not a bug report, it is a decision that was never taken.
Taking it: implicit widening does not cross a generic binding. A
concrete argument at a variable an earlier argument already bound has
to be that type, and both orders now refuse with the same sentence,
naming the binding, the argument, and the cast to write.
Refusing is the direction that can be walked back. Letting the pair
join at the wider type is a coherent rule too, and it can be added
later without invalidating a program written under this one; the
reverse is not true.
The rule costs almost nothing because Types.widens_to admits only
numeric scalars. A variable bound inside [$t] or (Fn [$t $t] bool)
leaves a parameter no widening ever applied to, so sort-by and the
whole fn-literal path are untouched by construction. Two exceptions
keep the ergonomics: an untyped literal has no type of its own to
keep, so it still takes the variable's; and a form with no type
without a want -- (zeroed) -- is asked for its natural type through a
trial, and falls back to the want it always had when the trial
refuses.
pos? over every numeric type from one definition was the motivating
example for milestone 5 and was the one thing the landed generics could
not write: (> x 0) refused with "expected t, found the integer literal
0", because int_literal had no arm for a want that is a type variable.
It has one now, and the bound is what makes it sound rather than
optimistic. Every type numeric? admits is an integer or a float, and an
untyped integer constant is usable at all of them, so there is no
instantiation of a numeric? variable at which the literal has no
meaning. Under a weaker bound there is -- ordered? admits an enum -- so
numeric? is what is asked for and the refusal names it.
The float literal is refused at a type variable even under numeric?,
and that asymmetry is the concrete arms' own: an integer constant is
usable where a float is wanted and a float literal is never usable
where an integer is wanted, so a body written with 0.5 has no meaning
at the integer half of its own bound. Refusing at the definition is
what the abstract pass is for; the alternative is a surprise at
whichever call site first asks for i32.
The node the abstract pass builds is never emitted. Each copy
re-checks the same form with the variable substituted, and that is
where the literal is built at the concrete width and range-checked --
so (+ x 300) is fine at i32 and a refusal at u8, and u8 is where it is
refused.
A defn named after a builtin wins for its whole file, and until now that
was the end of it: the builtin had no remaining spelling, so a defn that
meant to wrap one was unbounded recursion. builtin/len is the builtin len
wherever it is written, shadowed or not.
The qualifier is the package one's, and builtin is reserved rather than
resolved: Load refuses it as an import alias, Check refuses it as a
declaration's name, and those two doors are the only ways a qualifier can
be made. named_call and var each strip the prefix and re-enter with a flag
that the shadowing guard consults, so every arm below sees the bare name
and refuses in the builtin's own words.
The shadow warning now names the escape in its second half.
The leak review found: an importer's (defn len ...) reached inside an
imported package's (defvar sz i32 (len "abcd")) and made it 999. A global
initialiser is checked with no enclosing function, so the qualified name the
first cut asked about was not there to ask. The file the definition was
written in is what the shadow follows now, which is what FIX.org had already
named as the fix if it ever mattered. It mattered.
builtin_set beside builtin_names: the guard is the first arm of the dispatch
and ran a linear walk of eighty-odd strings at every named call. The list
stays for the did-you-mean, whose order is its order.
Pinned: a shadowed operator warns and lowers to a Call, and a call carrying
another file's name reaches the builtin. The corpus program grew both cases
and the package grew the initialiser that demonstrated the leak.
And the int/float section's sentence about "the arity precedent, where the
builtin wins" now says that the precedent was deleted the same day, since
this lane is what deleted it.
The author's rule: "allow shadowing but warn". A user (defn get ...) is
legal, the user's definition wins at every call site in the file that wrote
it, and the compiler warns once at the definition.
Builtin-wins was never a rule anybody wrote: named_call is one match on the
name, the builtin arms are string literals, and the three arms that look a
name up are the last three in it. So a guard goes first, the trailing three
are factored into ordinary_call, and both routes into it resolve a name the
same way.
The shadow stops at the file that declared it. An imported package's names
were qualified at the import, so a get written inside one is the builtin's
and stays the builtin's; the prelude is excluded by its file for the same
reason. programs/shadow-builtin.flan is both halves at once.
The warning prints from build_program, which is what every command and the
dev daemon's reload go through, in the shape --warn-memory established:
file:line:col, the squiggle, and an exit status that does not move.
And the message that described the old world is gone — the builtin-arity
note said a defn does not replace a builtin, which is no longer true and is
no longer reachable.
The author's exception to the foreign-spelling list: int is i32 and float
is f32, and nothing else on that list moves.
Spelled in Types.ikind_of_name and Types.fkind_of_name rather than as two
prelude defaliases, because Check.is_cast asks those two functions and never
the alias table — a prelude alias would have left (int x) with no reading
while (i32 x) had one. Both names join primitive_names for the same reason
one layer down: that list is what decides (vec-new int) and the three-element
(defvar x int).
Nothing reverses: ikind_name still says i32, so every message, signature,
inspector line and DWARF name shows the machine type whichever spelling was
written.
A defalias restating the builtin is the no-op it says it is; one pointing the
name anywhere else is refused, since the alias table is never consulted and
the declaration would otherwise mean i32 in silence.
1. The bare (dead-beef) built its default with Int64.of_int32, which
sign-extends 0xDEADBEEF to -559038737 on a node tagged u32 — where the
spelled-out literal arrives as 3735928559, because in_range admits it as
the unsigned value it is. Masked to 32 bits, so the two spellings really
do carry one payload; verified by diffing the emitted bodies of (dead-beef)
and (dead-beef 0xDEADBEEF), which are now identical instruction for
instruction.
2. The refusal's catch-all told a union and a function value that they
'carry a tag that names a case'. Neither does: env.unions is the untagged
unions, and an Fn is a code address. Split into one arm per reason —
union, Fn, enum, Option, data type — and each is now pinned, so they
cannot quietly re-merge. Same correction in FIX.org's bullet.
3. js.ml prefixed its own message with 'js: ', which bin/main.ml prepends
too, giving 'js: js: ...'. Dropped, and the message now names the builtin
it refuses, which its comment already claimed it did.
4. FIX.org said x86.ml reads both pattern helpers out of Emit. It reads only
word_of_pattern; the tail walks rax with shr.
F1 was the blocker and it was the worst kind of fault this pass can have: the
condition message told the reader to write (not= x 0), and not= does not
exist — the operator is !=. Applying the compiler's own advice got 'unknown
function not= — did you mean not?'. Both branches say != now, and all three
— the named form, the float zero, and the unnamed one — were checked by
compiling the sentence the compiler prints.
F5: a typo of a declared capitalised name got the generics lecture. (Piont 1
2) with Point declared was told that a capitalised name given type arguments
is milestone 5 work, which is a confident answer about a feature nobody was
reaching for. The did-you-mean runs first and, for a capitalised head only,
asks the type tables as well; the generics sentence is left for a head that
resembles nothing.
F2: flan_dyn_cast_kind had the site live and passed NULL on the trapping
path — the one entry point on this side that had a location and threw it
away. The acceptance row now pins the prefix it prints.
F3: the case-typo row used (data ...), which is not a top-level form, so it
refused as an unknown top-level form and the needle 'unknown' matched that
rather than the rule. Rewritten with defdata, and as a pair: a capitalised
head gets no accessor advice, a lowercase one does. Both halves were checked
to fail when perturbed.
F4: an end-to-end pin for the headline. programs/dyn-trap-site.flan is
compiled, run, and its stderr read for the file:line:col in front of the
sentence, on both backends and at -O0. Proven live: three failures when the
expected line is wrong.
F8: usize and size_t stay off the foreign-spelling list, and the comment now
says why — the honest answer is pointer-width, which is u64 here and u32 on
wasm32, and a tree that builds both cannot name one of them.
F10 pins the fourth dot shape. F6 moves the not-reached reasons out of the
commit bodies and into FIX.org, where they can be read without git.
DISCUSS.org's "need a value-producing array constructor": the author
wanted grid filled with 255 as part of its declaration and could not
write it. (array n T) produces the zeroed array only, and dotimes is
Unit, so it can mutate a place that already exists but cannot be the
initialiser expression -- which has to produce the whole value in one
go. The grid was declared zeroed and filled in main instead.
Two forms, both expressions, both any rank:
(array-fill [rows cols] 255) every element that value
(array-gen [rows cols] cell) every element (cell i j)
Spelled apart rather than one form dispatching on the third element's
type, because an array *of* function values is a thing to want and one
form would have to decide whether (array-fill [4] f) meant four copies
of f or four calls of it.
The dimensions are read in Parse, and that is the whole reason they are
recognised there: handed through as an ordinary call, [rows cols] is an
array literal of two names, and where those names are defconsts it is a
perfectly good two-element array of integers -- the wrong reading, and a
silent one. Read in Parse they are the same len the [n T] type spelling
takes, resolved by the same array_len, with one extra condition of their
own: the fill counts in i32 like every index in the language, so a
dimension no i32 can reach has no loop that could end.
The lowering is a loop over a slot, not an aggregate. Tast.Arr is the
node the backends have and both build it element by element from a list
as long as the array; a fill of [600 [800 u8]] is half a million
elements and there is no list to be had. So these bind the array to a
slot, zero it, run one While per dimension writing through Set of a
Pindex, and answer with the slot -- While, Set and Pindex, which is the
argument check_loop already makes for recur. Nothing new reaches a
backend and all three get the form with no edit. The value stays
value-like: the slot is the form's own, and the Local at the end copies
out the way any array-typed expression does.
Row-major is pinned, not incidental: the first dimension is the
outermost loop, and a generator that counts observes it. The fill value
and the generator value are each bound once before any loop starts, so
(array-fill [n] (next-id)) is one call and n copies of its answer.
What falls out for the defvar the note was written about, and neither
half is a carve-out:
(defvar grid [rows [cols u8]] (array-fill [rows cols] 255))
is the spelling that works -- a typed global with a computed
initialiser, which is the startup-lifted path with the init-once guard
that defvar already had, so the fill runs once and the value survives a
re-run like any other computed one. The three-element spelling means
what the 2026-09-20 rule says it means: not a type, so a dyn global, and
a typed fixed array crosses into dyn only as a view of storage that
outlives the view. A freshly built array is a temporary, so it is
refused -- by the element rule where the elements are themselves an
array, by the lifetime rule where they are one of the three scalars a
view carries. Both refusals are the ones any other temporary gets.
The type an array-fill builds never goes through resolve, so resolve's
own guard is asked again where it is built: a fixed array of function
values would be zeroed, and a zeroed function value is a null pointer.
The author's revision. The name says what it writes, and the pattern is the
program's to choose: (dead-beef) is DEADBEEF, (dead-beef 0xBAADF00D) is
BA AD F0 0D. One byte-order rule covers both — a pattern's ascending bytes
are its big-endian bytes, which is how the hex literal reads left to right —
so every candidate DISCUSS.org listed is now spellable without the compiler
naming any of them.
The bare form is not a case a backend knows about: the checker writes
Tast.dead_beef_default in where the argument would have been, so
(dead-beef) and (dead-beef 0xDEADBEEF) are the same node and an acceptance
row prints both to say so.
The operand is an ordinary u32 expression, which is what the byte arm
already accepts for its byte. A literal is byte-reversed at compile time and
still reaches the loop as an immediate; a computed one is reversed at run
time, by llvm.bswap.i32 on one backend and bswap on the other, after which
the tail shifts its bytes out of the word rather than folding them. The
program runs a computed pattern over lengths 6 and 7 deliberately: that is
the case a constant-only implementation would pass by accident.
filled is untouched, and so is the fill boundary.
DISCUSS.org's sentinel-fill idea, built as two builtins because the author
asked for both: a memset with a byte the program picks, and the fixed
DE AD BE EF pattern a hex dump reads as DEADBEEF.
Both are spelled the way (zeroed) is — the value of whatever type is
expected of them — so (set grid (filled 0xFF)) fills a place and there is
no second, place-taking form beside set.
What may be filled is numbers, and structs and fixed arrays built out of
them. Everything else is refused by name: a filled dyn is a collector root
pointing at nothing, a filled Vec header frees a wild address, a filled
slice length is a bounds check that passes, and a filled bool is an i1 to
LLVM and a whole byte to x86, which is the one divergence this feature
cannot have.
The byte fill is llvm.memset / rep stosb. The four-byte pattern cannot be
a memset on either side — the intrinsic takes one repeated i8 — so it is a
counted dword loop in emit.ml and rep stosd in x86.ml, with the pattern
bytes and their little-endian word living once, in Emit. A size that is
not a multiple of four ends on DE, DE AD, or DE AD BE.
(set p.x 1) was being told that a field is read with an accessor, which is a
sentence that does not apply to the form it is printed under. The place
spelling is (set (.x p) 1), checked to be a real form.
A bare {.field v} had its refusal in Parse.expr, before any checking, so a
defn whose return type was the only place the struct's name appeared could
not build one. The refusal moves to Check: Parse builds an Ast.Bare out of
the same struct_fields the named form uses, and check_bare reads the type
name off the expectation and hands that very list to check_struct. ZII, the
unknown-field refusal and the duplicate-field refusal are therefore not
copies of the named form's rules but the named form's rules.
Braces at a dyn want are the dyn map literal and stay exactly that. A
.field-keyed brace was never part of that spelling, and at a dyn want it is
refused by name rather than given a second meaning.
(Cell 1 2) is the other half, and it is character-for-character an ordinary
call, so only the symbol table separates them. It is decided on the last arm
of named_call, after a local of function type, a generic and the function
table -- so a defclass constructor, which is a real defn, resolves above it
and is untouched. Arity is exact: ZII is what the braces do, and a positional
list cannot say which field it left out, so it is not allowed to leave one
out. The refusal names the first field it did not reach and points at the
spelling that does mean "zero the rest".
Both are gone before any backend sees them -- Tast.Make either way -- and the
three acceptance rows print the same lines to say so.
Ranks 7, 10 and 19.
A defn whose name is a builtin's is silently unreachable — the dispatch
reaches every builtin arm before it looks in the function table — and the
arity refusal that followed measured the call against the builtin while
pointing at a call the reader had written for their own. The count stays the
builtin's, because the builtin is what runs; the message says so and notes
the definition that is not being reached. The shadowing itself is not
refused: that is a language decision and not a fix pass's to make.
FIX.org recorded and's misdirected caret with three rejected fixes and one
accepted — check_if preferring the arm that is not a compiler temp — and said
it was a check.ml change nobody owned. and's last operand is its then arm and
the sentinel carrying the previous operand's location is its else arm, so the
mismatch landed one operand early. Only and needs it: in an or the chain is
already in the else arm, and with an expectation in hand neither arm is
checked against the other.
'expanding this declaration produced 2 of them' had no antecedent once read
cold. The head of the expanded form is the macro's name and says what
expanded, and the expression form names (do ...).
Ranks 13, 14 and 9.
A body form in the return slot was blamed at whatever leaf the type parser
gave up on — the [1] in [(defn f [x i32] (+ x 1))], three forms deep — where
the mistake is that the whole form is in the slot. The slot is blamed now and
the parser's own reason keeps its span as a note. Where the parser gave up on
the slot form itself the old shape stands, because a message like 'unit is
written (), not Unit' already names the right thing and leading with it is
better than restating it. The literal -- is an em dash now, like everything
else in the tree.
A one-field case binds the payload itself, so [(match s (Circle c) (.r c))]
reached for a field of an f64 and got a type fact. The binding carries what
the pattern made it, in words, derived at the arm from the case and the
subject; the refusal says the value is already in hand. Set by that path and
nowhere else, so every other binding's refusal says exactly what it said.
The missing collection asserted a thing and contradicted it in the same
sentence — 'is a directory named nosuch somewhere above X, and there is
none'. It states the rule and the two ends of the search instead. The bare
/. it printed was Filename.concat of a directory and a dot, and is cleaned
where the path is made absolute.
Ranks 15, 6, 11 and 18, all of them the same fault in different words — the
message states a fact the reader already had and leaves out the half only the
compiler can see.
'k is a constant' was four words. It says what a constant is, names defvar,
and notes the defconst — [no_container_defconst] is the house's shape for
this and [declared_note]'s is the note's.
(let [x i32 5] ...) is what everyone arriving from a typed language writes,
and let has no annotation slot, so the i32 became x's value and the 5 was
left over: 'binding 5 has no value', which reads as if they had miscounted.
The annotation is blamed now, at its own span. Checked only when the vector
was about to be refused anyway, and the test for 'this names a type' is
syntactic because nothing resolves at parse time.
The unterminated string had one column on the opening quote and no note,
alone among this reader's three two-place errors. It has the same note its
neighbours have.
'+ takes numbers, found string' pointed at the whole form when the operand
was right there — the same whole-form-vs-operand fault the condition work
fixed once already. Text gets the extra clause it was reaching for, naming
concat and join without a call shape: the spelling that builds a slice of
byte slices out of string literals is not a clause in a sentence, and a
message that guessed at one would be wrong.
The four the defvar review left behind, plus the two the author's dogfooding
notes name.
A three-element defvar that is neither a type nor a value gets a paragraph
about the fork it stands at, and the paragraph is right for the name that
genuinely could have been either. Three names cannot: a data case, which is
a third thing with its own spelling; a name another language uses for a type
this one has; and a plain type typo, where a confident one-edit suggestion
was turning a line into four. Each answers first now.
A bracket form never reaches that fork at all — the parser gives it the type
reading outright — so a value name inside one landed in [resolve_name] and
came back as a lecture about generic code. Both readings at the element that
decided it, and the dyn spelling it offers is checked to be a real form.
[int] is two edits from [i32] and so outside the one-edit net, correctly:
two edits is a guess. But the name is not a guess, it is what four other
languages call the default integer, so a short list answers it by name.
Nothing goes on that list without one honest answer — [char] and [void] are
off it, and the comment says why.
A parameter called [i] is not a mistyped [i8]. The machine types size
themselves in the name, so a typo keeps the digits and a parameter name has
none; that is the rule that stopped (defn idx [v i] dyn ...) being refused.
A type written in a two-element defconst was reported as an unknown name,
because that form has no type slot and the brackets read as an array
literal. A type name inside one is unambiguous — a type and a value cannot
share a name here — so it says what happened and names defvar.
Two register warts alongside: no message cites a repo filename at the reader
any more (plan.org in three, spec-memory.md in one).
Two of the audit's top five, and both are the same complaint: the message
states a type fact and stops where the reader needed the other half.
A call argument's refusal now says which argument of which function it is and
notes the parameter's own declaration, which is [declared_note]'s shape moved
to the place the audit calls the most-hit message in the compiler. [fns]
threw the parameter names and locations away when it resolved the types, so
[fparams] keeps the vector as written; a foreign declare and a generic copy
have no entry and degrade to the message alone rather than a wrong pointer.
The enrichment is conditional on the refusal being raised against the
argument's own span, so a mismatch deeper inside it is not misattributed, and
the rekind stops a nested call being named twice.
A condition that is neither bool nor dyn now states the rule instead of the
fact, with the comparison spelled out using the condition's own name where it
has one. Two things it does not do: it does not offer a comparison for a type
that has no zero, and it does not say anything about the dyn side, where
Clojure's truthiness means 0 is true. The re-check at bool still runs first
and its answer is kept wherever it knows more — a literal names itself, and
[None] names itself, and both beat a type name.
Two of the audit's four cheapest structural wins, and they share a raise
point. [p.x] is how C, Go and Odin spell field access, and it arrived here as
the symbol [p.x] and left as 'unknown name p.x' — true, and no use to anyone.
The head is looked up now, so the refusal can say what [p] actually is, and
the struct's declaration comes along as a note. A capitalised head is left
alone: [Shape.Circle] is a real spelling and a typo in one is a mistyped case.
[near_miss] was written, tested and wired to the type tables alone, so a
mistyped value name got the bare refusal. [one_edit] is hoisted out of it so
the value side matches on the same rule rather than a second one that would
drift, and the candidate list at a value position is the scope, the globals
and the functions — plus, at a call, the builtin names, which live in no
table the checker keeps and reach the raise through a forward reference.
Two repairs alongside: the data-type message's format string carried eleven
stray spaces from a wrapped line, and (Pair i32) in a defvar had lost the
type fork's 'generics are milestone 5' answer when it started falling down
the value fork.
The dyn arithmetic and ordering entry points printed their sentence with no
file, no line and no column, which in a dynamic-first language is the type
error arriving from nowhere. flan_rt.c's bounds and arithmetic traps have
taken an emitter-threaded (loc, loclen) pair since they were written, and
[flan_dyn_cast_kind] is the fresh precedent on the dyn side; this is the same
pair, threaded through [arith], [want_nums] and [order] to the five
arithmetic and four ordering entry points. [eq] never traps and takes none.
The three trap printers take the pair and print nothing for a NULL loc, so
every other call site in the file — and test/dyn_ops.c, which calls the
runtime directly and has no source position — keeps its sentence byte for
byte. [trap_oom] is left alone: it is reached from [gc_alloc], which has no
site to be given and would have had to grow one on every allocation path in
the file for no reader's benefit.
A defclass is a named dyn map with a shape tag, and a generic function
dispatches on it two ways: CLOS's, where the dispatch value is the class
of the first argument, and Clojure's, where a body computes it. They are
one mechanism and not two — a class dispatcher is (class-of arg0) as the
dispatch function, which is what lets a method written for the class
point and one written for the value :point be the same branch.
(defclass point [x y])
(point 3 4) ; the constructor, positional
(class-of p) ; :point, or nil for anything else
(defgeneric area [self] dyn)
(defmethod area point [p] (* (get p :x) (get p :y)))
(defmulti describe [x] dyn (get x :kind))
(defmethod describe :square [s] ...)
(defmethod describe :else [s] ...)
A slot is a key in the instance's own map, so get, put and has-key? are
how one is read and written and no operation was added for any of it.
What the class adds is the tag, and the tag lives in the object's header
rather than in a reserved entry — the queue's note said a reserved key
and this departs from it, because a key would be counted by len, walked
by the renderer and compared by equality, so every instance would answer
a length one larger than its slot count and print a key nobody wrote. A
header field cannot be reached by get or put at all, so no user key can
collide with it. It costs nothing: the map arm of flan_obj's union grows
to the size the view arm already had, and sizeof(flan_obj) is unchanged.
It needs no tracing either — the tag is an interned keyword entry, which
is immortal and is not a collector object.
The tag shows up in exactly three places: class-of answers it, equality
compares it (two instances of one class compare by their slots; an
instance and a plain map with the same entries do not, which is
Clojure's answer for a record beside a map), and both renderers print it
— #point{ :x 1 :y 2}, Clojure's own spelling.
None of the four forms reaches the checker. lib/classes.ml turns the
whole declaration list into ordinary defns at the top of build_program,
the way Shim.expand already turns a declare-c into a declare plus a
defn: a class becomes its constructor, a generic becomes one function
whose body binds the dispatch value and compares it down a chain, and a
method becomes a branch of that chain. It is a pass and not a macro
because a macro sees one form and the generic's body is not decidable
until every method is in hand — a method may be written above its
generic, below it, or arrive at a reload an hour later.
That last case is why the method bodies are inlined rather than lifted.
A generic is exactly one top-level name, so adding a method to a running
program is the ordinary redefinition of one function, through the cell
every call site already goes through. session.ml names the generic
alongside the method's own declaration name for that reason. The cost,
recorded rather than hidden: a method is not separately callable and is
not a frame of its own.
A dispatch that finds no method signals NoMethod, a prelude struct
carrying the generic's name and the dispatch value that missed. A
condition and not a trap, because a miss is something a program can be
written to answer, and handler-case around the call is the shape. Its
value field is dyn, the first condition here with one; the per-type
descriptor an item-2 struct carries is what the collector reaches it by.
No restart is established at the miss, which is BoundsError's decision
taken for BoundsError's reason.
Both backends, identically: the two new runtime entry points are
declared in emit.ml and the x86 backend needs nothing, since a dyn call
is a dyn call there. Deferred and written down in FIX.org: inheritance,
multi-argument dispatch, :before/:after/:around, named-slot
construction, unknown-slot checking, and computed dispatch values.
const_defconst_init matched MakeCase at the top level only, so a case nested in
a struct literal got the general computed message, whose advice nobody could
follow. Emit.const found it by recursing; this finds it the same way, left to
right and first offender wins, which is the order the emitter spelled fields
in. FIX.org's claim that the messages did not change is rewritten to say what
did change about the general one.
The refusal moves to the checker: Emit.const refused a computed defconst by
name while the x86 backend ran it through the startup function behind an
.init~once. flag, like a defvar, so the two backends disagreed about the same
program. One refusal in Check.const_defconst_init ends that, and it is the only
place that can name the way through.
The accepted set is unchanged: Tast.const_init's, which is Emit.const's and the
x86 data_sym path's, plus the integer arithmetic collect's folding pass has
already turned into an Int before the initialiser is looked at.
Emit.const's two refusals become a failwith no program reaches; emit_global's
gconst || const_init loses its left half; x86 needed no edit, since it never
classified by the form. test_flan's infers probe asks Check.expression now that
a defconst can no longer wrap an arbitrary expression.
flan.abi.require was spelled by hand in both backends, which is the one
job Mangle has. Moved; emit and x86 produce byte-identical output on the
reload path either way.
Four comments in the dyn-cast code asserted things that are not true.
The warning's location prefix now reads like every other loc-bearing
runtime diagnostic instead of inventing a shape. widen's contract says
what cast_dyn actually does with it. The thread-safety note names the
torn {ptr,len} overread rather than a duplicated line, and says why no
lock. The site table's borrowed loc pointer names what keeps it valid.
The memory op's note claimed a completeness it does not have: dyn push
and put may allocate and are deliberately silent. Said so, in the note,
in the classifier, and in FIX.org where the decision belongs.
The documented flycheck form only matched warnings, so a real error
made it say the checker returned non-zero and found nothing.
flan-clear-memory cleared one buffer where the toggle clears all.
Two comments claimed test/dyn_ops.c calls every function flan_dyn.h
declares; six are declared and never called there.
flan_dyn_stub.c's deadness is written into FIX.org for the author to
decide on. Not deleted here.
[Check.memory_sites] is the pass [Check.no_gc]'s shape: it runs over the
finished program, answers a diagnostic list, and tells nothing downstream
that it ran. Two classes on the diagnostic's kind — the collector's heap
and an allocator the program named — so the CLI, the daemon and the editor
dispatch on one field and none of them reads a message to find the class.
[--warn-memory] on check and build prints them where errors go, in the
shape flycheck parses, without moving the exit status. [(:op "memory")]
answers the same list over a session's last checked program, needing no
program on the far end. [M-x flan-check-memory] paints it two faces fainter
than an error's, cleared by an edit or by asking again.
Two of the spec's own examples turned out not to allocate, and the
precision rule outranks the enumeration: (vec-new T) passes a capacity of
literal zero to flan_vec_init, which returns before the grow, and
flan_map_init takes no block at all and says so in its own comment. The
block arrives at the first push, which is the line that is marked. The
classifier reads the capacity argument rather than the symbol, which is
what lets slurp be marked through the same entry point vec-new is silent
through. FIX.org has the rest of the evidence.
get and map-remove asked the runtime the same question through two
identical bodies; only the symbol differed, so map_lookup takes it and
both entry points keep their own preambles and their own prose.
invented_ctx existed and six sites still wrote the sixteen-field literal
out by hand. All six go through it now — three verbatim, three with the
two or three fields that make them a written body rather than an
invented one — so a field added to the record is one edit.
dyn_descriptors and dyn_sites each walked every place a value can live,
and the two walks had already drifted: an unnamed frame slot was "a
local of f" in one and "a local in f" in the other. One value_sites
walker now, with the callers' filters kept on their side; the surviving
text is "a local in f", because a named slot has always read "n in f"
and neither spelling was pinned by a test.
The duplicate-field scan appeared three times and the ZII fill twice —
check_case's own comment conceded the copy. given_once and zii_fill.
The union keeps its unknown-member pass ahead of the scan rather than
folding it in, because that ordering is what it reports today.
(at g i j) is one Tast node carrying the whole index list, so the At
arm's guard on target.ty settled level zero and nothing after it. A
global [2 [[3 i64]]] indexed twice reached a slice's element, crossed
into dyn as a view, and printed a returned frame's contents with exit
0 (ASan: stack-use-after-scope in view_box). The arm now steps each
index the way [indexed] does and demands an array at every level;
the Field and Slice arms inherit the fix by recursing into it.
