| [/============================================================================== |
| Copyright (C) 2001-2010 Joel de Guzman |
| Copyright (C) 2001-2010 Hartmut Kaiser |
| |
| Distributed under the Boost Software License, Version 1.0. (See accompanying |
| file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| ===============================================================================/] |
| |
| This quick reference section is provided for convenience. You can use |
| this section as a sort of a "cheat-sheet" on the most commonly used Lex |
| components. It is not intended to be complete, but should give you an |
| easy way to recall a particular component without having to dig through |
| pages and pages of reference documentation. |
| |
| [/////////////////////////////////////////////////////////////////////////////] |
| [section Common Notation] |
| |
| [variablelist Notation |
| [[`L`] [Lexer type]] |
| [[`l, a, b, c, d`] [Lexer objects]] |
| [[`Iterator`] [The type of an iterator referring to the underlying |
| input sequence]] |
| [[`IdType`] [The token id type]] |
| [[`Context`] [The lexer components `Context` type]] |
| [[`ch`] [Character-class specific character (See __char_class_types__)]] |
| [[`Ch`] [Character-class specific character type (See __char_class_types__)]] |
| [[`str`] [Character-class specific string (See __char_class_types__)]] |
| [[`Str`] [Character-class specific string type (See __char_class_types__)]] |
| [[`Attrib`] [An attribute type]] |
| [[`fa`] [A semantic action function with a signature: |
| `void f(Iterator&, Iterator&, pass_flag&, Idtype&, Context&)`.]] |
| ] |
| |
| [endsect] |
| |
| [/////////////////////////////////////////////////////////////////////////////] |
| [section:lexers Primitive Lexer Components] |
| |
| [table |
| [[Expression] [Attribute] [Description]] |
| [[`ch`] [n/a] [Matches `ch`]] |
| [[`char_(ch)`] [n/a] [Matches `ch`]] |
| [[`str`] [n/a] [Matches regular expression `str`]] |
| [[`string(str)`] [n/a] [Matches regular expression `str`]] |
| [[`token_def<Attrib>`] [`Attrib`] [Matches the immediate argument]] |
| [[`a | b`] [n/a] [Matches any of the expressions `a` or `b`]] |
| [[`l[fa]`] [Attribute of `l`] [Call semantic action `fa` (after matching `l`).]] |
| ] |
| |
| [note The column /Attribute/ in the table above lists the parser attribute |
| exposed by the lexer component if it is used as a parser (see |
| __attribute__). A 'n/a' in this columns means the lexer component is not |
| usable as a parser.] |
| |
| [endsect] |
| |
| [/////////////////////////////////////////////////////////////////////////////] |
| [section Semantic Actions] |
| |
| Has the form: |
| |
| l[f] |
| |
| where `f` is a function with the signatures: |
| |
| void f(); |
| void f(Iterator&, Iterator&); |
| void f(Iterator&, Iterator&, pass_flag&); |
| void f(Iterator&, Iterator&, pass_flag&, Idtype&); |
| void f(Iterator&, Iterator&, pass_flag&, Idtype&, Context&); |
| |
| You can use __boost_bind__ to bind member functions. For function |
| objects, the allowed signatures are: |
| |
| void operator()(unused_type, unused_type, unused_type, unused_type, unused_type) const; |
| void operator()(Iterator&, Iterator&, unused_type, unused_type, unused_type) const; |
| void operator()(Iterator&, Iterator&, pass_flag&, unused_type, unused_type) const; |
| void operator()(Iterator&, Iterator&, pass_flag&, Idtype&, unused_type) const; |
| void operator()(Iterator&, Iterator&, pass_flag&, Idtype&, Context&) const; |
| |
| The `unused_type` is used in the signatures above to signify 'don't |
| care'. |
| |
| For more information see __lex_actions__. |
| |
| [endsect] |
| |
| [/////////////////////////////////////////////////////////////////////////////] |
| [section Phoenix] |
| |
| __boost_phoenix__ makes it easier to attach semantic actions. You just |
| inline your lambda expressions: |
| |
| l[phoenix-lambda-expression] |
| |
| __lex__ provides some __boost_phoenix__ placeholders to access important |
| information from the `Context` that are otherwise difficult to extract. |
| |
| [variablelist Spirit.Lex specific Phoenix placeholders |
| [[`_start, _end`] [Iterators pointing to the begin and the end of the |
| matched input sequence.]] |
| [[`_pass`] [Assign `lex::pass_flags::pass_fail` to `_pass` to force the current match to fail.]] |
| [[`_tokenid`] [The token id of the matched token.]] |
| [[`_val`] [The token value of the matched token.]] |
| [[`_state`] [The lexer state the token has been matched in.]] |
| [[`_eoi`] [Iterator referring to the current end of the input sequence.]] |
| ] |
| |
| [tip All of the placeholders in the list above (except `_eoi`) can be changed |
| from the inside of the semantic action allowing to modify the lexer |
| behavior. They are defined in the namespace `boost::spirit::lex`.] |
| |
| For more information see __lex_actions__. |
| |
| [endsect] |
| |
| |
