Currently, the compiler (like @typeName) writes it `fn(...) Type` but
zig fmt writes it `fn (...) Type` (notice the space after `fn`).
This inconsistency is now resolved and function types are consistently
written the zig fmt way. Before this there were more `fn (...) Type`
occurrences than `fn(...) Type` already.
This change implements the following syntax into the compiler:
```zig
const x: u32, var y, foo.bar = .{ 1, 2, 3 };
```
A destructure expression may only appear within a block (i.e. not at
comtainer scope). The LHS consists of a sequence of comma-separated var
decls and/or lvalue expressions. The RHS is a normal expression.
A new result location type, `destructure`, is used, which contains
result pointers for each component of the destructure. This means that
when the RHS is a more complicated expression, peer type resolution is
not used: each result value is individually destructured and written to
the result pointers. RLS is always used for destructure expressions,
meaning every `const` on the LHS of such an expression creates a true
stack allocation.
Aside from anonymous array literals, Sema is capable of destructuring
the following types:
* Tuples
* Arrays
* Vectors
A destructure may be prefixed with the `comptime` keyword, in which case
the entire destructure is evaluated at comptime: this means all `var`s
in the LHS are `comptime var`s, every lvalue expression is evaluated at
comptime, and the RHS is evaluated at comptime. If every LHS is a
`const`, this is not allowed: as with single declarations, the user
should instead mark the RHS as `comptime`.
There are a few subtleties in the grammar changes here. For one thing,
if every LHS is an lvalue expression (rather than a var decl), a
destructure is considered an expression. This makes, for instance,
`if (cond) x, y = .{ 1, 2 };` valid Zig code. A destructure is allowed
in almost every context where a standard assignment expression is
permitted. The exception is `switch` prongs, which cannot be
destructures as the comma is ambiguous with the end of the prong.
A follow-up commit will begin utilizing this syntax in the Zig compiler.
Resolves: #498
Most of this migration was performed automatically with `zig fmt`. There
were a few exceptions which I had to manually fix:
* `@alignCast` and `@addrSpaceCast` cannot be automatically rewritten
* `@truncate`'s fixup is incorrect for vectors
* Test cases are not formatted, and their error locations change
This can be used to escape the usual meaning of `_` to indicate a
non-exhaustive enum and create an enum tag that is a literal underscore,
so zig fmt should allow this syntax.
Before, zig fmt changes
const E = enum { @"_" };
to the semantically different
const E = enum { _ };
After, it remains the same.
* Scan from line start when finding tag in tokenizer
This resolves a crash that can occur for invalid bytes like carriage
returns that are valid characters when not parsed from within literals.
There are potentially other edge cases this could resolve as well, as
the calling code for this function didn't account for any potential
'pending_invalid_tokens' that could be queued up by the tokenizer from
within another state.
* Fix carriage return crash in multiline string
Follow the guidance of #38:
> However CR directly before NL is interpreted as only a newline and not part of the multiline string. zig fmt will delete the CR.
Zig fmt already had code for deleting carriage returns, but would still
crash - now it no longer does so. Carriage returns encountered before
line-feeds are now appropriately removed on program compilation as well.
* Only accept carriage returns before line feeds
Previous commit was much less strict about this, this more closely
matches the desired spec of only allow CR characters in a CRLF pair, but
not otherwise.
* Fix CR being rejected when used as whitespace
Missed this comment from ziglang/zig-spec#83:
> CR used as whitespace, whether directly preceding NL or stray, is still unambiguously whitespace. It is accepted by the grammar and replaced by the canonical whitespace by zig fmt.
* Add tests for carriage return handling
* improve error message when build manifest file is missing
* update std.zig.Ast to support ZON
* Compilation.AllErrors.Message: make the notes field a const slice
* move build manifest parsing logic into src/Manifest.zig and add more
checks, and make the checks integrate into the standard error
reporting code so that reported errors look sexy
closes#14290
* std.zig.parse is moved to std.zig.Ast.parse
* the new function has an additional parameter that requires passing
Mode.zig or Mode.zon
* moved parser.zig code to Parse.zig
* added parseZon function next to parseRoot function
* allow file level `union {}` to parse as tuple field
this was found while fuzzing zls.
* before this patch the input `union {}` crashed the parser. after
this, it parses correctly just like `struct {}`.
* adds behavior tests for both inputs `struct {}` and `union {}`,
checking that each becomes a file level tuple field.
these were found while fuzzing zls.
this patch prevents overflow for the following file contents and adds
tests for them.
* `enum(u32)` - causes overflow in std.zig.Ast.fullContainerDecl()
* `*x` - causes overflow in std.zig.Ast.fullPtrType()
* `**x` - causes overflow in std.zig.Ast.firstToken()
There are still a few occurrences of "stage1" in the standard library
and self-hosted compiler source, however, these instances need a bit
more careful inspection to ensure no breakage.
