diff options
Diffstat (limited to 'libbuild2/lexer.hxx')
| -rw-r--r-- | libbuild2/lexer.hxx | 38 |
1 files changed, 23 insertions, 15 deletions
diff --git a/libbuild2/lexer.hxx b/libbuild2/lexer.hxx index 749668e..d5f1c99 100644 --- a/libbuild2/lexer.hxx +++ b/libbuild2/lexer.hxx @@ -31,7 +31,9 @@ namespace build2 // values). The attributes/attribute_value modes are like values where each // value is potentially a variable assignment; they don't treat `{` and `}` // as special (so we cannot have name groups in attributes) as well as - // recognizes `=` and `]`. The eval mode is used in the evaluation context. + // recognizes `=` and `]`. The subscript mode is like value but doesn't + // treat `{` and `}` as special and recognizes `]`. The eval mode is used in + // the evaluation context. // // A number of modes are "derived" from the value/values mode by recognizing // a few extra characters: @@ -55,10 +57,10 @@ namespace build2 // mode data. // // The alternative modes must be set manually. The value/values and derived - // modes automatically expires after the end of the line. The attribute mode - // expires after the closing `]`. The variable mode expires after the word - // token. The eval mode expires after the closing `)`. And the foreign mode - // expires after the closing braces. + // modes automatically expires after the end of the line. The attribute and + // subscript modes expires after the closing `]`. The variable mode expires + // after the word token. The eval mode expires after the closing `)`. And + // the foreign mode expires after the closing braces. // // Note that normally it is only safe to switch mode when the current token // is not quoted (or, more generally, when you are not in the double-quoted @@ -66,13 +68,13 @@ namespace build2 // variable name mode). Failed that your mode (which now will be the top of // the mode stack) will prevent proper recognition of the closing quote. // - // Finally, attributes recognition (the `[` token) cuts across most of the - // modes and is handled with a flag. In the normal mode it is automatically - // set at the beginning and after each newline. In all other modes it must - // be explicitly set at points where attributes are recognized. In all the - // cases it is automatically reset after lexing the next token (whether `[` - // or not). - // + // The `[` token is used for attributes (where it cuts across most of the + // modes) as well as for value subscript (where it is only recognized after + // expansions). It is handled with a flag. In the normal mode it is + // automatically set at the beginning and after each newline. In all other + // modes it must be explicitly set at points where attribute/subscript is + // recognized. In all the cases it is automatically reset after lexing the + // next token (whether `[` or not). // Extendable/inheritable enum-like class. // @@ -91,6 +93,7 @@ namespace build2 switch_expressions, attributes, attribute_value, + subscript, eval, single_quoted, double_quoted, @@ -134,10 +137,14 @@ namespace build2 optional<const char*> escapes = nullopt, uintptr_t data = 0); - // Enable attributes recognition for the next token. + // Enable `[` recognition for the next token. // void - enable_attributes () {state_.top ().attributes = true;} + enable_lsbrace (bool unsep = false) + { + state_.top ().lsbrace = true; + state_.top ().lsbrace_unsep = unsep; + } // Expire the current mode early. // @@ -177,7 +184,8 @@ namespace build2 uintptr_t data; optional<token> hold; - bool attributes; + bool lsbrace; // Recognize `[`. + bool lsbrace_unsep; // Recognize it only if unseparated. char sep_pair; bool sep_space; // Are whitespaces separators (see skip_spaces())? |