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Diffstat (limited to 'src/commandline.lalrpop')
| -rw-r--r-- | src/commandline.lalrpop | 66 |
1 files changed, 0 insertions, 66 deletions
diff --git a/src/commandline.lalrpop b/src/commandline.lalrpop deleted file mode 100644 index d52e741..0000000 --- a/src/commandline.lalrpop +++ /dev/null @@ -1,66 +0,0 @@ -grammar; - -pub Invocation: Vec<&'input str> = { - <WORD*>, -}; - -// Several of the regexps below make use of Unicode character classes. [1] is -// the official reference to Unicode classes, and [2] is a site that is useful -// for browsing to get an intuitive idea of what the classes mean. -// -// In maintaining these regexps, it's important to understand the structure -// of Unicode character classes. There are seven top-level categories, each -// with a single-character name (ie. "Z" for separators). Each top-level -// category has several subcategories which form an exhaustive partition of it; -// the subcategories have two-character names (ie. "Zs" for space separators). -// Every allocated codepoint is in exactly one top-level category and exactly -// one subcategory. -// -// It is important that these regexps exhaustively cover the entirety of -// Unicode, without omission; otherwise lalrpop's lexer will give InvalidToken -// errors for unrecognized characters. Overlaps will be less catastrophic, as -// they'll be resoved by the precedence rules, but for clarity's sake they -// should be avoided. -// -// [1] http://www.unicode.org/reports/tr44/#General_Category_Values -// [2] https://www.compart.com/en/unicode/category -// -match { - // Zs is the Unicode class for space separators. This includes the ASCII - // space character. - // - r"\p{Zs}+" => { }, - - // Zl is the Unicode class for line separators. Zp is the Unicode class for - // paragraph separators. Newline and carriage return are included individually - // here, since Unicode classifies them with the control characters rather than - // with the space characters. - // - r"[\p{Zl}\p{Zp}\n\r]" => NEWLINE, - - // This one recognizes exactly one character, the old-school double-quote. As - // tempting as it is to do something clever with character classes, shells have - // a long history of quoting syntaxes which are subtle and quick to anger, and - // for this project the decision is to be radically simple instead. - r#"["]"# => QUOTE, - - // This one matches any control character other than line feed and carriage - // return. The grammar doesn't reference control characters, but having a - // token for them makes the error messages more informative. - r"[\p{C}&&[^\n\r]]" => CONTROL, - - // Z is the unicode class for separators, which is exhaustively partitioned - // into line, paragraph, and space separators. Each of those subclasses is - // handled above. C is the class for control characters. This regexp tests - // for the intersection of the negation of these character classes, along - // with a negated class enumerating all the explicitly-recognized characters, - // which means it matches any character NOT in the regexps above. - // - // Note that, counterintuitively, line feed and carriage return are classified - // as control characters, not as line separators. Either way, this regexp would - // still exclude them, but the difference might be relevant when maintaining - // it. - // - r#"[\P{Z}&&\P{C}&&[^"]]+"# => WORD, -} - |