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| author | Ryo Nihei <nihei.dev@gmail.com> | 2022-06-12 00:40:28 +0900 |
|---|---|---|
| committer | Ryo Nihei <nihei.dev@gmail.com> | 2022-06-12 09:44:00 +0900 |
| commit | 2dd098d1e16bd0b8786ca97ccc7d3b06fa6bc3d1 (patch) | |
| tree | 2e5a9ffa712ffe553d5ecafb35e27a7a3cd1fa11 /spec/grammar/syntax_error.go | |
| parent | Support the underscore symbol matching any symbols in vartan-test command (diff) | |
| download | urubu-2dd098d1e16bd0b8786ca97ccc7d3b06fa6bc3d1.tar.gz urubu-2dd098d1e16bd0b8786ca97ccc7d3b06fa6bc3d1.tar.xz | |
Prohibit using a pattern in an alternative
When a syntax error occurs, the parser must provide a user with the names of expected tokens.
However, if a pattern appears directly in an alternative, Vartan cannot assign an appropriate name to the pattern.
Therefore, this commit prohibits alternatives from containing patterns.
Diffstat (limited to 'spec/grammar/syntax_error.go')
| -rw-r--r-- | spec/grammar/syntax_error.go | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/spec/grammar/syntax_error.go b/spec/grammar/syntax_error.go index 1fec801..1f9664b 100644 --- a/spec/grammar/syntax_error.go +++ b/spec/grammar/syntax_error.go @@ -37,6 +37,7 @@ var ( synErrNoDirectiveName = newSyntaxError("a directive needs a name") synErrNoOrderedSymbolName = newSyntaxError("an ordered symbol name is missing") synErrUnclosedDirGroup = newSyntaxError("a directive group must be closed by )") + synErrPatternInAlt = newSyntaxError("a pattern literal cannot appear directly in an alternative. instead, please define a terminal symbol with the pattern literal") synErrStrayExpOp = newSyntaxError("an expansion operator ... must be preceded by an identifier") synErrInvalidExpOperand = newSyntaxError("an expansion operator ... can be applied to only an identifier") synErrSemicolonNoNewline = newSyntaxError("a semicolon must be followed by a newline") |