Nested transformBody/liftLambdas passes used a fresh DetectionPass, so
getEnvTypeForOwner could allocate a duplicate PType for the same owner
while :envP already referenced the inner pass type. When addClosureParam
saw cp.typ != t, it errored.
If both types are env objects for the same routine owner, reuse cp.typ
and sync ownerToType.
Adds regression test tests/iter/t21242_nested_closure_in_iter.nim.
fixes#25687
This pull request introduces an optimization for sequence (`seq`)
assignments and copies in the Nim compiler, enabling bulk memory copying
for sequences whose element types are trivially copyable (i.e., no GC
references or destructors). This can significantly improve performance
for such types by avoiding per-element loops.
Key changes:
### Compiler code generation improvements
* Added the `elemSupportsCopyMem` function in
`compiler/liftdestructors.nim` to detect if a sequence's element type is
trivially copyable (no GC refs, no destructors).
* Updated the `fillSeqOp` procedure to use a new `genBulkCopySeq` code
path for eligible element types, generating a call to
`nimCopySeqPayload` for efficient bulk copying. Fallback to the
element-wise loop remains for non-trivial types.
[[1]](diffhunk://#diff-456118dde9a4e21f1b351fd72504d62fc16e9c30354dbb9a3efcb95a29067863R665-R670)
[[2]](diffhunk://#diff-456118dde9a4e21f1b351fd72504d62fc16e9c30354dbb9a3efcb95a29067863R623-R655)
### Runtime support
* Introduced the `nimCopySeqPayload` procedure in
`lib/system/seqs_v2.nim`, which performs the actual bulk memory copy of
sequence data using `copyMem`. This is only used for types that are safe
for such an operation.
These changes collectively improve the efficiency of sequence operations
for simple types, while maintaining correctness for complex types.
### Benchmarked the original micro-benchmark:
refc: 3.52s user 0.02s system 99% cpu 3.538 total
orc (after change): 3.46s user 0.01s system 99% cpu 3.476 total
---------
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
This fixes type resolution for `iterable[T]`.
I want to proceed with RFC
[#562](https://github.com/nim-lang/RFCs/issues/562) and this is the main
blocker for composability.
Fixes#22098 and, arguably, #19206
```nim
import std/strutils
template collect[T](it: iterable[T]): seq[T] =
block:
var res: seq[T] = @[]
for x in it:
res.add x
res
const text = "a b c d"
let words = text.split.collect()
doAssert words == @[ "a", "b", "c", "d" ]
```
In cases like `strutils.split`, where both proc and iterator overload
exists, the compiler resolves to the `func` overload causing a type
mismatch.
The old mode resolved `text.split` to `seq[string]` before the
surrounding `iterable[T]` requirement was applied, so the argument no
longer matched this template.
It should be noted that, compared to older sequtils templates,
composable chains based on `iterable[T]` require an iterator-producing
expression, e.g. `"foo".items.iterableTmpl()` rather than just
`"foo".iterableTmpl()`. This is actually desirable: it keeps the
iteration boundary explicit and makes iterable-driven templates
intentionally not directly interchangeable with older
untyped/loosely-typed templates like those in `sequtils`, whose internal
iterator setup we have zero control over (e.g. hard-coding adapters like
`items`).
Also, I noticed in `semstmts` that anonymous iterators are always
`closure`, which is not that surprising if you think about it, but still
I added a paragraph to the manual.
Regarding implementation:
From what I gathered, the root cause is that `semOpAux` eagerly
pre-types all arguments with plain flags before overload resolution
begins, so by the time `prepareOperand` processes `split` against the
`iterable[T]`, the wrong overload has already won.
The fix touches a few places:
- `prepareOperand` in `sigmatch.nim`:
When `formal.kind == tyIterable` and the argument was already typed as
something else, it's re-semchecked with the
`efPreferIteratorForIterable` flag. The recheck is limited to direct
calls (`a[0].kind in {nkIdent, nkAccQuoted, nkSym, nkOpenSym}`) to avoid
recursing through `semIndirectOp`/`semOpAux` again.
- `iteratorPreference` field `TCandidate`, checked before
`genericMatches` in `cmpCandidates`, gives the iterator overload a win
without touching the existing iterator heuristic used by `for` loops.
**Limitations:**
The implementation is still flag-driven rather than purely
formal-driven, so the behaviour is a bit too broad `efWantIterable` can
cause iterator results to be wrapped as `tyIterable` in
iterable-admitting contexts, not only when `iterable[T]` match is being
processed.
`iterable[T]` still does not accept closure iterator values such
as`iterator(): T {.closure.}`. It only matches the compiler's internal
`tyIterable`, not arbitrary iterator-typed values.
The existing iterator-preference heuristic is still in place, because
when I tried to remove it, some loosely-related regressions happened. In
particular, ordinary iterator-admitting contexts and iterator chains
still rely on early iterator preference during semchecking, before the
compiler has enough surrounding context to distinguish between
value/iterator producing overloads. Full heuristic removal would require
a broader refactor of dot-chain/intermediate-expression semchecking,
which is just too much for me ATM. This PR narrows only the
tyIterable-specific cases.
**Future work:**
Rework overload resolution to preserve additional information of
matching iterator overloads for calls up to the point where the
iterator-requiring context is established, to avoid re-sem in
`prepareOperand`.
Currently there's no good channel to store that information. Nodes can
get rewritten, TCandidate doesn't live long enough, storing in Context
or some side-table raises the question how to properly key that info.
fixes#25682
This pull request introduces a fix to the Nim compiler's assignment code
generation logic to better handle statement list expressions, and adds
regression tests to ensure correct behavior when assigning to object
fields via templates. The changes address a specific bug (#25682)
related to assignments using templates with side effects in static
contexts.
**Compiler code generation improvements:**
* Updated the `genAsgn` procedure in `compiler/vmgen.nim` to properly
handle assignments where the left-hand side is a `nkStmtListExpr`
(statement list expression), ensuring all statements except the last are
executed before the assignment occurs.
**Regression tests for assignment semantics:**
* Added new test blocks in `tests/vm/tvmmisc.nim` to verify that
template-based assignments to object fields work as expected in static
contexts, specifically testing for bug #25682.
fixes#25632fixes#25631fixes#25630
This pull request introduces a compatibility check between the
`{.error.}` and `{.exportc.}` pragmas in procedure declarations.
Specifically, it prevents a procedure from being marked with both
pragmas at the same time, as this combination is now considered invalid.
Pragma compatibility enforcement:
* Added a check in `semProcAux` (in `compiler/semstmts.nim`) to emit a
local error if a procedure is declared with both `{.error.}` and
`{.exportc.}` pragmas, preventing their incompatible usage.
time_t should be a 64-bit type on all relevant windows CRT versions
including mingw-w64 - MSDN recommends against using the 32-bit version
which only is happens when `_USE_32BIT_TIME_T` is explicitly defined -
instead of guessing (and guessing wrong, as happens with recent mingw
versions), we can simply use the 64-bit version always.
```nim
template compute(body: untyped): int =
block:
body
let x = compute:
var sum = 0
for i in 1..10: sum += i
sum
echo x
```
supersedes https://github.com/nim-lang/Nim/pull/25653
which in
02893e2f4c
```nim
of nkSym:
genSingleVar(p, it.sym, newSymNode(it.sym), it.sym.astdef)
```
A new branch for `nkSym` is added, though more changes might be needed
if `nkSym` is handled specifically
fixes#25677;
fixes#25678
This pull request introduces both a bug fix to the type checking logic
in the compiler and new test cases for lent types involving procedures
and tables. The most significant change is a refinement in how type
flags are handled for procedure and function types in the compiler,
which improves correctness in type allowance checks. Additionally, the
test suite is expanded to cover more complex scenarios with lent types
and table lookups.
**Compiler improvements:**
* Refined the handling of type flags in `typeAllowedAux` for procedure
and function types by introducing `innerFlags`, which removes certain
flags (`taObjField`, `taTupField`, `taIsOpenArray`) before recursing
into parameter and return types. This ensures more accurate type
checking and prevents inappropriate flag propagation.
**Testing enhancements:**
* Added new test blocks in `tests/lent/tlents.nim` to cover lent
procedure types stored in objects and used as table values, including a
function that retrieves such procedures from a table by key.
* Introduced a test case for an object containing a lent procedure
field, ensuring correct behavior when accessing and using these fields.
Fixes bug #25674.
`replace` read `s[i+1]` for a CRLF pair without ensuring `i+1 <
s.len()`, so a value ending in a lone `\\c` (quoted in `writeConfig`)
raised `IndexDefect`.
- Fix: only treat `\\c\\l` when the following character exists.
- Test: `tests/stdlib/tparsecfg.nim` block bug #25674 — fails before
fix, passes after.
Fixes bug #25670.
The second argument to `max` in `cmpDecimalsIgnoreCase` used `limitB -
iA` instead of `limitB - iB`, which could mis-order numeric segments
when sorting doc index entries.
Fixes bug #25671.
The previous condition `not value > 0` was parsed as `(not value) > 0`,
not `not (value > 0)`, so the check did not reliably enforce a positive
`--maxLoopIterationsvm` limit. Align with `--maxcalldepthvm` by using
`value <= 0`.
`toNifFilename` proc doesn't return correct Nif file path because module
suffix is registered with wrong proc.
So `moduleFromNifFile` doesn't load the Nif file.
fixes#25626
This pull request introduces a small change to the `mapIt` template in
`sequtils.nim`. The update adds the `used` pragma to the injected `it`
variable, which can help suppress unused variable warnings in certain
cases.
- Added the `used` pragma to the injected `it` variable in the `mapIt`
template to prevent unused variable warnings.
or it should give a better warning or something if `it` is not used
- Small optimizations for mobile, makes code render slightly tighter.
- `font-stretch: semi-condensed;` for pre works if the user's font
provides such a face, shouldn’t change the rendering with the default.
- Removes an excessive page break after the page header when printing.
Co-authored-by: ringabout <43030857+ringabout@users.noreply.github.com>
Small changes to the default html template and the `nimdoc.css`.
Adds a burger button to show the navigation panel when on narrow
screens/mobile. Displayed when the panel gets hidden.
Second element click or click on the dimmed background ides the panel.
# Demo:
This pull request includes a few targeted changes across the codebase,
primarily focusing on improving symbol locality detection in the
compiler, adding a utility function for integer division and modulus,
and simplifying a test case.
- **Compiler Improvements**
* Improved the `isLocalSym` function in `compiler/ast2nif.nim` to more
accurately determine if a symbol is local by checking that the symbol's
owner is not a module.
- **Utility Function Addition**
* Added a new `divmod` procedure in `tests/ic/tmiscs.nim` that returns
both the quotient and remainder of integer division, along with a usage
example.
- **Test Simplification**
* Simplified the `showMeters` test in `tests/ic/tconverter.nim` by
removing a floating-point assertion, leaving only an output statement.
------------------------------------------------------------------------------------------------------------------
```nim
proc divmod(a, b: int): (int, int) =
(a div b, a mod b)
let (q, r) = divmod(17, 5)
echo q
echo r
```
gives `Error: unhandled exception: local symbol 'tmpTuple.0' not found
in localSyms. [AssertionDefect]`
`makeVarTupleSection` uses a temp of which the globalness and localness
is not specified. Turning it a global variable for top level scope broke
some Nim programs. So I think it's better to check the owner of the
symbol
```nim
if useTemp:
# use same symkind for compatibility with original section
let temp = newSym(symkind, getIdent(c.cache, "tmpTuple"), c.idgen, getCurrOwner(c), n.info)
```
fixes#25620
This pull request includes a fix to the type key generation logic in the
compiler and updates to a test file to cover additional language
features. The most important changes are summarized below:
### Compiler logic fix
* In `compiler/typekeys.nim`, the `typeKey` procedure was updated to
iterate over all elements in `t.sonsImpl` starting from index 0 instead
of 1, ensuring that all type sons are considered during type key
generation.
### Test suite improvements
* The test file `tests/ic/tenum.nim` was renamed to
`tests/ic/tmiscs.nim`, and its output expectations were updated to
reflect the new test cases.
* Added new test cases to `tests/ic/tmiscs.nim` to cover sink and move
semantics, including the definition of a `BigObj` type and a `consume`
procedure that demonstrates moving and consuming large objects.
```nim
# Sink and move semantics
type
BigObj = object
data: seq[int]
proc consume(x: sink BigObj) =
echo x.data.len
var b = BigObj(data: @[1, 2, 3, 4, 5])
consume(move b)
```
gives
```
error: passing 'tySequence__qwqHTkRvwhrRyENtudHQ7g' (aka 'struct tySequence__qwqHTkRvwhrRyENtudHQ7g') to parameter of incompatible type 'tySequence__cTyVHeHOWk5jStsToosJ8Q' (aka 'struct tySequence__cTyVHeHOWk5jStsToosJ8Q')
84 | eqdestroy___sysma2dyk_u75((*dest_p0).data);
```
follows up https://github.com/nim-lang/Nim/pull/25614
fixes#25611
This pull request updates the `propagateToOwner` procedure in
`compiler/ast.nim` to handle sealed types more robustly during
incremental compilation (IC) reloads. The main change is the addition of
an assertion to ensure that sealed types already have the necessary
propagated flags, preventing incorrect state during IC reloads.
Handling of sealed types and propagated flags:
* Added a check for `Sealed` state on `o2` (the owner type), and
included an assertion to verify that sealed types already have the
required propagated flags (`tfHasAsgn`/`tfHasOwned`) during IC reloads,
instead of redundantly setting them.
It seems in dispute whether changes to code induced to avoid this new
warning firing are worthwhile.
Until either the analyzer is better or a palatable way to adjust stdlib
code not warn is found, verbosity=1 should not include the warning.
Possibly higher levels, too, but this PR is conservative and only takes
it out at the 2->1 transition.
I've been wondering why the inline code was rendered wrapped with no
regards to words/whitespace for a while.
Partially reverts 8b82f5 (#24927)
- `word-break: break-all;` This is seriously wrong, replaced with
`overflow-wrap: break-word;`
- `white-space: normal;` -> `pre-wrap;` to preserve whitespace in code
spans.
- Added `display: block;` and `overflow-x: auto;` to tables. This
contains wide tables with their own scrollbars without stretching the
whole doc.
- `overflow-x: hidden;` just clips content and possibly conflicts with
navbar's `sticky` attribute. Removed.
In `createTypeStub` proc, `k`, `itemId` and `suffix` are used only when
`c.types.getOrDefault(name)[0]` returned nil.
So moves them under `if result == nil:` branch.
In `extractLocalSymsFromTree` proc, removes unnecessary `inc depth` and
`dec depth`.
Compiling following code with `nim ic test.nim` or `nim m test.nim`
generated compile errors.
```nim
var s: seq[int]
newSeq(s, 1)
```
This PR fixes above bug.
This bug was caused by wrong PType/PSym tree generated by
`ast2nif.loadSym` proc because generic param symbols in NIF files have
all `0`.
`TSym.instantiatedFromImpl` is not related to the bug but it seems all
field of `TSym` should be copied in `transitionSymKindCommon` template.
Follows up #25269, refs #25265.
I hit the same bug as #25265 for my own project but #25269 does not fix
it, I think because the type in my case is a `tyGenericInst` which does
not trigger the generation here. First I thought of skipping abstract
type kinds instead of checking for a raw `tyObject`, which fixes my
problem. But in general this could maybe also be encountered for
`tyTuple` and `tySequence` etc. So I figured it might just be safest to
not filter on specific type kinds, ~~which is done now~~ (edit: broke
CI). Maybe this has a slight cost on codegen performance though.
Edit: Allowing all types failed CI for some reason as commented below,
trying skipped type version again.
This fixes autogenerated references within the same-module for types,
variables and constants for custom output file names. Previously, the
module name was baked-in, now intra-module links omit the page name in
href.
In short, fixes symbol anchors for `-o:index.html`
Expected test results updated.
`getTypeImpl` and friends were always putting `nkEmpty` in the default
value field which meant the default values couldn't be introspected.
This copies the default AST so it can be seen in the returned object
On simple code like:
```nim
type Foo = object
case x: range[0..7]
of 0..2:
a: string
else:
b: string
var foo = Foo()
{.cast(uncheckedAssign).}:
foo.x = 5
```
The compiler tries to generate a destructor for the variant fields by
checking if the discrim is equal to the old one, but the type is not
skipped when looking for an `==` operator in system, so any
discriminator with type `range`/`distinct`/etc crashes with:
```
(10, 9) Error: can't find magic equals operator for type kind tyRange
```
This is fixed by just skipping abstract types.
This fixes highlighter's tokenization of char literals inside
parentheses and brackets.
The Nim syntax highlighter in `docutils/highlite.nim` incorrectly
tokenizes character literals that appear after punctuation characters,
such as all kinds of brackets.
For `echo('v', "hello")`, the tokenizer treated the first `'` as
punctuation because the preceding token was punctuation `(`. As a
result, the second `'` (after `v`) was interpreted as the start of a
character literal and the literal incorrectly extended to the end of the
line.
See other examples in the screenshot:
<img width="508" height="266" alt="Screenshot 2026-03-04 at 16-09-06
_y_test"
src="https://github.com/user-attachments/assets/94d991ae-79d2-4208-a046-6ed4ddcb5c34"
/>
This regression originates from a condition added in PR #23015 that
prevented opening a `gtCharLit` token when the previous token kind was
punctuation. Nim syntax allows character literals after punctuation such
as `(`, `[`, `{`, `:`, `;`, or `,`, of course. The only case mentioned
in the manual explicitly that actually requires special handling is
stroped proc declaration for literals (see the [last paragraph
here](https://nim-lang.github.io/Nim/manual.html#lexical-analysis-character-literals)):
```nim
proc `'customLiteral`(s: string)
```
This PR narrows the conditional to not entering charlit only after
backticks.
So the problem is that Nim Language Server won't show procs like \`+\`
and \`==\` in the Document Symbols or Workspace Symbols lists. Which is
really annoying given they are regular procs just named a bit
differently.
Initially, I thought the problem was with nim-lang/langserver and opened
an issue there: https://github.com/nim-lang/langserver/issues/380
But after an investigation, it turned out the issue is fixed on the
nimsuggest side.
Strangely enough, calling `outline foo.nim:0:0` in nimsuggest manually
does show \`+\` as well as regular procs (e.g. `foo`) but when
nimsuggest is invoked from lsp only `foo` would be there.
Anyway, with this fix all procs appear on the symbol lists.
withTimeout currently leaves the “losing” callback installed:
- when fut finishes first, timeout callback remains until timer fires,
- when timeout fires first, fut callback remains on the wrapped future.
Under high-throughput use with large future payloads, this retains
closures/future references longer than needed and causes large transient
RSS growth.
This patch clears the opposite callback immediately once outcome is
decided, reducing retention without changing API behavior.
