spirit/doc/lex/lexer_api.qbk
Nikita Kniazev 8e385e9d85 Lex: Removed variadic tokenize_and_phrase_parse
They were added 10 years ago and did not compile all the time due to bugs
spotted during warning elimination work, but the main reason to remove them
is that there was not a single report about the issues.
2019-04-19 02:53:23 +03:00

190 lines
7.4 KiB
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[/==============================================================================
Copyright (C) 2001-2011 Joel de Guzman
Copyright (C) 2001-2011 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)
===============================================================================/]
[section:lexer_api Lexer API]
[heading Description]
The library provides a couple of free functions to make using the lexer a snap.
These functions have three forms. The first form, `tokenize`, simplifies the
usage of a stand alone lexer (without parsing). The second form,
`tokenize_and_parse`, combines a lexer step with parsing on
the token level (without a skipper). The third, `tokenize_and_phrase_parse`,
works on the token level as well, but additionally employs a skip parser. The
latter two versions can take in attributes by reference that will hold the
parsed values on a successful parse.
[heading Header]
// forwards to <boost/spirit/home/lex/tokenize_and_parse.hpp>
#include <boost/spirit/include/lex_tokenize_and_parse.hpp>
For variadic attributes:
// forwards to <boost/spirit/home/lex/tokenize_and_parse_attr.hpp>
#include <boost/spirit/include/lex_tokenize_and_parse_attr.hpp>
The variadic attributes version of the API allows one or more
attributes to be passed into the API functions. The functions taking two
or more attributes are usable when the parser expression is a
__qi_sequence__ only. In this case each of the
attributes passed have to match the corresponding part of the sequence.
Also, see __include_structure__.
[heading Namespace]
[table
[[Name]]
[[`boost::spirit::lex::tokenize` ]]
[[`boost::spirit::lex::tokenize_and_parse` ]]
[[`boost::spirit::lex::tokenize_and_phrase_parse` ]]
[[`boost::spirit::qi::skip_flag::postskip` ]]
[[`boost::spirit::qi::skip_flag::dont_postskip` ]]
]
[heading Synopsis]
The `tokenize` function is one of the main lexer API functions. It
simplifies using a lexer to tokenize a given input sequence. It's main
purpose is to use the lexer to tokenize all the input.
Both functions take a pair of iterators spanning the underlying input
stream to scan, the lexer object (built from the token definitions),
and an (optional) functor being called for each of the generated tokens. If no
function object `f` is given, the generated tokens will be discarded.
The functions return `true` if the scanning of the input succeeded (the
given input sequence has been successfully matched by the given
token definitions).
The argument `f` is expected to be a function (callable) object taking a single
argument of the token type and returning a bool, indicating whether
the tokenization should be canceled. If it returns `false` the function
`tokenize` will return `false` as well.
The `initial_state` argument forces lexing to start with the given lexer state.
If this is omitted lexing starts in the `"INITIAL"` state.
template <typename Iterator, typename Lexer>
inline bool
tokenize(
Iterator& first
, Iterator last
, Lexer const& lex
, typename Lexer::char_type const* initial_state = 0);
template <typename Iterator, typename Lexer, typename F>
inline bool
tokenize(
Iterator& first
, Iterator last
, Lexer const& lex
, F f
, typename Lexer::char_type const* initial_state = 0);
The `tokenize_and_parse` function is one of the main lexer API
functions. It simplifies using a lexer as the underlying token source
while parsing a given input sequence.
The functions take a pair of iterators spanning the underlying input
stream to parse, the lexer object (built from the token definitions)
and a parser object (built from the parser grammar definition). Additionally
they may take the attributes for the parser step.
The function returns `true` if the parsing succeeded (the given input
sequence has been successfully matched by the given grammar).
template <typename Iterator, typename Lexer, typename ParserExpr>
inline bool
tokenize_and_parse(
Iterator& first
, Iterator last
, Lexer const& lex
, ParserExpr const& expr)
template <typename Iterator, typename Lexer, typename ParserExpr
, typename Attr1, typename Attr2, ..., typename AttrN>
inline bool
tokenize_and_parse(
Iterator& first
, Iterator last
, Lexer const& lex
, ParserExpr const& expr
, Attr1 const& attr1, Attr2 const& attr2, ..., AttrN const& attrN);
The functions `tokenize_and_phrase_parse` take a pair of iterators spanning
the underlying input stream to parse, the lexer object (built from the token
definitions) and a parser object (built from the parser grammar definition).
The additional skipper parameter will be used as the skip parser during
the parsing process. Additionally they may take the attributes for the parser
step.
The function returns `true` if the parsing succeeded (the given input
sequence has been successfully matched by the given grammar).
template <typename Iterator, typename Lexer, typename ParserExpr
, typename Skipper>
inline bool
tokenize_and_phrase_parse(
Iterator& first
, Iterator last
, Lexer const& lex
, ParserExpr const& expr
, Skipper const& skipper
, BOOST_SCOPED_ENUM(skip_flag) post_skip = skip_flag::postskip);
template <typename Iterator, typename Lexer, typename ParserExpr
, typename Skipper, typename Attribute>
inline bool
tokenize_and_phrase_parse(
Iterator& first
, Iterator last
, Lexer const& lex
, ParserExpr const& expr
, Skipper const& skipper
, Attribute& attr);
template <typename Iterator, typename Lexer, typename ParserExpr
, typename Skipper, typename Attribute>
inline bool
tokenize_and_phrase_parse(
Iterator& first
, Iterator last
, Lexer const& lex
, ParserExpr const& expr
, Skipper const& skipper
, BOOST_SCOPED_ENUM(skip_flag) post_skip, Attribute& attr);
The maximum number of supported arguments is limited by the preprocessor
constant `SPIRIT_ARGUMENTS_LIMIT`. This constant defaults to the value defined
by the preprocessor constant `PHOENIX_LIMIT` (which in turn defaults to `10`).
[note The variadic function with two or more attributes internally combine
references to all passed attributes into a `fusion::vector` and forward
this as a combined attribute to the corresponding one attribute function.]
The `tokenize_and_phrase_parse` functions not taking an explicit `skip_flag`
as one of their arguments invoke the passed skipper after a successful match
of the parser expression. This can be inhibited by using the other versions of
that function while passing `skip_flag::dont_postskip` to the corresponding
argument.
[heading Template parameters]
[table
[[Parameter] [Description]]
[[`Iterator`] [__fwditer__ pointing to the underlying input sequence to parse.]]
[[`Lexer`] [A lexer (token definition) object.]]
[[`F`] [A function object called for each generated token.]]
[[`ParserExpr`] [An expression that can be converted to a Qi parser.]]
[[`Skipper`] [Parser used to skip white spaces.]]
[[`Attr1`, `Attr2`, ..., `AttrN`][One or more attributes.]]
]
[endsect]