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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 /README.md | |
| 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 'README.md')
| -rw-r--r-- | README.md | 2 |
1 files changed, 1 insertions, 1 deletions
@@ -302,7 +302,7 @@ Alternative: <element-1> <element-2> ... <element-N> ``` -An element an alternative contains is a terminal symbol, a non-terminal symbol, a pattern, or a string literal. +An element an alternative contains is a terminal symbol, a non-terminal symbol, or a string literal. Unlike string literals, patterns cannot be contained in alternatives. You can define terminal symbols in the same grammar as non-terminal symbols. |