boost/xpressive/regex_primitives.hpp
///////////////////////////////////////////////////////////////////////////////
/// \file regex_primitives.hpp
/// Contains the syntax elements for writing static regular expressions.
//
// Copyright 2008 Eric Niebler. 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)
#ifndef BOOST_XPRESSIVE_REGEX_PRIMITIVES_HPP_EAN_10_04_2005
#define BOOST_XPRESSIVE_REGEX_PRIMITIVES_HPP_EAN_10_04_2005
#include <vector>
#include <climits>
#include <boost/config.hpp>
#include <boost/assert.hpp>
#include <boost/mpl/if.hpp>
#include <boost/mpl/and.hpp>
#include <boost/mpl/assert.hpp>
#include <boost/detail/workaround.hpp>
#include <boost/preprocessor/cat.hpp>
#include <boost/xpressive/detail/detail_fwd.hpp>
#include <boost/xpressive/detail/core/matchers.hpp>
#include <boost/xpressive/detail/core/regex_domain.hpp>
#include <boost/xpressive/detail/utility/ignore_unused.hpp>
// Doxygen can't handle proto :-(
#ifndef BOOST_XPRESSIVE_DOXYGEN_INVOKED
# include <boost/proto/core.hpp>
# include <boost/proto/transform/arg.hpp>
# include <boost/proto/transform/when.hpp>
# include <boost/xpressive/detail/core/icase.hpp>
# include <boost/xpressive/detail/static/compile.hpp>
# include <boost/xpressive/detail/static/modifier.hpp>
#endif
namespace boost { namespace xpressive { namespace detail
{
typedef assert_word_placeholder<word_boundary<mpl::true_> > assert_word_boundary;
typedef assert_word_placeholder<word_begin> assert_word_begin;
typedef assert_word_placeholder<word_end> assert_word_end;
// workaround msvc-7.1 bug with function pointer types
// within function types:
#if BOOST_WORKAROUND(BOOST_MSVC, == 1310)
#define mark_number(x) proto::call<mark_number(x)>
#define minus_one() proto::make<minus_one()>
#endif
struct push_back : proto::callable
{
typedef int result_type;
template<typename Subs>
int operator ()(Subs &subs, int i) const
{
subs.push_back(i);
return i;
}
};
struct mark_number : proto::callable
{
typedef int result_type;
template<typename Expr>
int operator ()(Expr const &expr) const
{
return expr.mark_number_;
}
};
typedef mpl::int_<-1> minus_one;
// s1 or -s1
struct SubMatch
: proto::or_<
proto::when<basic_mark_tag, push_back(proto::_data, mark_number(proto::_value)) >
, proto::when<proto::negate<basic_mark_tag>, push_back(proto::_data, minus_one()) >
>
{};
struct SubMatchList
: proto::or_<SubMatch, proto::comma<SubMatchList, SubMatch> >
{};
template<typename Subs>
typename enable_if<
mpl::and_<proto::is_expr<Subs>, proto::matches<Subs, SubMatchList> >
, std::vector<int>
>::type
to_vector(Subs const &subs)
{
std::vector<int> subs_;
SubMatchList()(subs, 0, subs_);
return subs_;
}
#if BOOST_WORKAROUND(BOOST_MSVC, == 1310)
#undef mark_number
#undef minus_one
#endif
// replace "Expr" with "keep(*State) >> Expr"
struct skip_primitives : proto::transform<skip_primitives>
{
template<typename Expr, typename State, typename Data>
struct impl : proto::transform_impl<Expr, State, Data>
{
typedef
typename proto::shift_right<
typename proto::unary_expr<
keeper_tag
, typename proto::dereference<State>::type
>::type
, Expr
>::type
result_type;
result_type operator ()(
typename impl::expr_param expr
, typename impl::state_param state
, typename impl::data_param
) const
{
result_type that = {{{state}}, expr};
return that;
}
};
};
struct Primitives
: proto::or_<
proto::terminal<proto::_>
, proto::comma<proto::_, proto::_>
, proto::subscript<proto::terminal<set_initializer>, proto::_>
, proto::assign<proto::terminal<set_initializer>, proto::_>
, proto::assign<proto::terminal<attribute_placeholder<proto::_> >, proto::_>
, proto::complement<Primitives>
>
{};
struct SkipGrammar
: proto::or_<
proto::when<Primitives, skip_primitives>
, proto::assign<proto::terminal<mark_placeholder>, SkipGrammar> // don't "skip" mark tags
, proto::subscript<SkipGrammar, proto::_> // don't put skips in actions
, proto::binary_expr<modifier_tag, proto::_, SkipGrammar> // don't skip modifiers
, proto::unary_expr<lookbehind_tag, proto::_> // don't skip lookbehinds
, proto::nary_expr<proto::_, proto::vararg<SkipGrammar> > // everything else is fair game!
>
{};
template<typename Skip>
struct skip_directive
{
typedef typename proto::result_of::as_expr<Skip>::type skip_type;
skip_directive(Skip const &skip)
: skip_(proto::as_expr(skip))
{}
template<typename Sig>
struct result;
template<typename This, typename Expr>
struct result<This(Expr)>
{
typedef
SkipGrammar::impl<
typename proto::result_of::as_expr<Expr>::type
, skip_type const &
, mpl::void_ &
>
skip_transform;
typedef
typename proto::shift_right<
typename skip_transform::result_type
, typename proto::dereference<skip_type>::type
>::type
type;
};
template<typename Expr>
typename result<skip_directive(Expr)>::type
operator ()(Expr const &expr) const
{
mpl::void_ ignore;
typedef result<skip_directive(Expr)> result_fun;
typename result_fun::type that = {
typename result_fun::skip_transform()(proto::as_expr(expr), this->skip_, ignore)
, {skip_}
};
return that;
}
private:
skip_type skip_;
};
/*
///////////////////////////////////////////////////////////////////////////////
/// INTERNAL ONLY
// BOOST_XPRESSIVE_GLOBAL
// for defining globals that neither violate the One Definition Rule nor
// lead to undefined behavior due to global object initialization order.
//#define BOOST_XPRESSIVE_GLOBAL(type, name, init) \
// namespace detail \
// { \
// template<int Dummy> \
// struct BOOST_PP_CAT(global_pod_, name) \
// { \
// static type const value; \
// private: \
// union type_must_be_pod \
// { \
// type t; \
// char ch; \
// } u; \
// }; \
// template<int Dummy> \
// type const BOOST_PP_CAT(global_pod_, name)<Dummy>::value = init; \
// } \
// type const &name = detail::BOOST_PP_CAT(global_pod_, name)<0>::value
*/
} // namespace detail
/// INTERNAL ONLY (for backwards compatibility)
unsigned int const repeat_max = UINT_MAX-1;
///////////////////////////////////////////////////////////////////////////////
/// \brief For infinite repetition of a sub-expression.
///
/// Magic value used with the repeat\<\>() function template
/// to specify an unbounded repeat. Use as: repeat<17, inf>('a').
/// The equivalent in perl is /a{17,}/.
unsigned int const inf = UINT_MAX-1;
/// INTERNAL ONLY (for backwards compatibility)
proto::terminal<detail::epsilon_matcher>::type const epsilon = {{}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Successfully matches nothing.
///
/// Successfully matches a zero-width sequence. nil always succeeds and
/// never consumes any characters.
proto::terminal<detail::epsilon_matcher>::type const nil = {{}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches an alpha-numeric character.
///
/// The regex traits are used to determine which characters are alpha-numeric.
/// To match any character that is not alpha-numeric, use ~alnum.
///
/// \attention alnum is equivalent to /[[:alnum:]]/ in perl. ~alnum is equivalent
/// to /[[:^alnum:]]/ in perl.
proto::terminal<detail::posix_charset_placeholder>::type const alnum = {{"alnum", false}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches an alphabetic character.
///
/// The regex traits are used to determine which characters are alphabetic.
/// To match any character that is not alphabetic, use ~alpha.
///
/// \attention alpha is equivalent to /[[:alpha:]]/ in perl. ~alpha is equivalent
/// to /[[:^alpha:]]/ in perl.
proto::terminal<detail::posix_charset_placeholder>::type const alpha = {{"alpha", false}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches a blank (horizonal white-space) character.
///
/// The regex traits are used to determine which characters are blank characters.
/// To match any character that is not blank, use ~blank.
///
/// \attention blank is equivalent to /[[:blank:]]/ in perl. ~blank is equivalent
/// to /[[:^blank:]]/ in perl.
proto::terminal<detail::posix_charset_placeholder>::type const blank = {{"blank", false}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches a control character.
///
/// The regex traits are used to determine which characters are control characters.
/// To match any character that is not a control character, use ~cntrl.
///
/// \attention cntrl is equivalent to /[[:cntrl:]]/ in perl. ~cntrl is equivalent
/// to /[[:^cntrl:]]/ in perl.
proto::terminal<detail::posix_charset_placeholder>::type const cntrl = {{"cntrl", false}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches a digit character.
///
/// The regex traits are used to determine which characters are digits.
/// To match any character that is not a digit, use ~digit.
///
/// \attention digit is equivalent to /[[:digit:]]/ in perl. ~digit is equivalent
/// to /[[:^digit:]]/ in perl.
proto::terminal<detail::posix_charset_placeholder>::type const digit = {{"digit", false}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches a graph character.
///
/// The regex traits are used to determine which characters are graphable.
/// To match any character that is not graphable, use ~graph.
///
/// \attention graph is equivalent to /[[:graph:]]/ in perl. ~graph is equivalent
/// to /[[:^graph:]]/ in perl.
proto::terminal<detail::posix_charset_placeholder>::type const graph = {{"graph", false}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches a lower-case character.
///
/// The regex traits are used to determine which characters are lower-case.
/// To match any character that is not a lower-case character, use ~lower.
///
/// \attention lower is equivalent to /[[:lower:]]/ in perl. ~lower is equivalent
/// to /[[:^lower:]]/ in perl.
proto::terminal<detail::posix_charset_placeholder>::type const lower = {{"lower", false}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches a printable character.
///
/// The regex traits are used to determine which characters are printable.
/// To match any character that is not printable, use ~print.
///
/// \attention print is equivalent to /[[:print:]]/ in perl. ~print is equivalent
/// to /[[:^print:]]/ in perl.
proto::terminal<detail::posix_charset_placeholder>::type const print = {{"print", false}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches a punctuation character.
///
/// The regex traits are used to determine which characters are punctuation.
/// To match any character that is not punctuation, use ~punct.
///
/// \attention punct is equivalent to /[[:punct:]]/ in perl. ~punct is equivalent
/// to /[[:^punct:]]/ in perl.
proto::terminal<detail::posix_charset_placeholder>::type const punct = {{"punct", false}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches a space character.
///
/// The regex traits are used to determine which characters are space characters.
/// To match any character that is not white-space, use ~space.
///
/// \attention space is equivalent to /[[:space:]]/ in perl. ~space is equivalent
/// to /[[:^space:]]/ in perl.
proto::terminal<detail::posix_charset_placeholder>::type const space = {{"space", false}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches an upper-case character.
///
/// The regex traits are used to determine which characters are upper-case.
/// To match any character that is not upper-case, use ~upper.
///
/// \attention upper is equivalent to /[[:upper:]]/ in perl. ~upper is equivalent
/// to /[[:^upper:]]/ in perl.
proto::terminal<detail::posix_charset_placeholder>::type const upper = {{"upper", false}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches a hexadecimal digit character.
///
/// The regex traits are used to determine which characters are hex digits.
/// To match any character that is not a hex digit, use ~xdigit.
///
/// \attention xdigit is equivalent to /[[:xdigit:]]/ in perl. ~xdigit is equivalent
/// to /[[:^xdigit:]]/ in perl.
proto::terminal<detail::posix_charset_placeholder>::type const xdigit = {{"xdigit", false}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Beginning of sequence assertion.
///
/// For the character sequence [begin, end), 'bos' matches the
/// zero-width sub-sequence [begin, begin).
proto::terminal<detail::assert_bos_matcher>::type const bos = {{}};
///////////////////////////////////////////////////////////////////////////////
/// \brief End of sequence assertion.
///
/// For the character sequence [begin, end),
/// 'eos' matches the zero-width sub-sequence [end, end).
///
/// \attention Unlike the perl end of sequence assertion \$, 'eos' will
/// not match at the position [end-1, end-1) if *(end-1) is '\\n'. To
/// get that behavior, use (!_n >> eos).
proto::terminal<detail::assert_eos_matcher>::type const eos = {{}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Beginning of line assertion.
///
/// 'bol' matches the zero-width sub-sequence
/// immediately following a logical newline sequence. The regex traits
/// is used to determine what constitutes a logical newline sequence.
proto::terminal<detail::assert_bol_placeholder>::type const bol = {{}};
///////////////////////////////////////////////////////////////////////////////
/// \brief End of line assertion.
///
/// 'eol' matches the zero-width sub-sequence
/// immediately preceeding a logical newline sequence. The regex traits
/// is used to determine what constitutes a logical newline sequence.
proto::terminal<detail::assert_eol_placeholder>::type const eol = {{}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Beginning of word assertion.
///
/// 'bow' matches the zero-width sub-sequence
/// immediately following a non-word character and preceeding a word character.
/// The regex traits are used to determine what constitutes a word character.
proto::terminal<detail::assert_word_begin>::type const bow = {{}};
///////////////////////////////////////////////////////////////////////////////
/// \brief End of word assertion.
///
/// 'eow' matches the zero-width sub-sequence
/// immediately following a word character and preceeding a non-word character.
/// The regex traits are used to determine what constitutes a word character.
proto::terminal<detail::assert_word_end>::type const eow = {{}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Word boundary assertion.
///
/// '_b' matches the zero-width sub-sequence at the beginning or the end of a word.
/// It is equivalent to (bow | eow). The regex traits are used to determine what
/// constitutes a word character. To match a non-word boundary, use ~_b.
///
/// \attention _b is like \\b in perl. ~_b is like \\B in perl.
proto::terminal<detail::assert_word_boundary>::type const _b = {{}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches a word character.
///
/// '_w' matches a single word character. The regex traits are used to determine which
/// characters are word characters. Use ~_w to match a character that is not a word
/// character.
///
/// \attention _w is like \\w in perl. ~_w is like \\W in perl.
proto::terminal<detail::posix_charset_placeholder>::type const _w = {{"w", false}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches a digit character.
///
/// '_d' matches a single digit character. The regex traits are used to determine which
/// characters are digits. Use ~_d to match a character that is not a digit
/// character.
///
/// \attention _d is like \\d in perl. ~_d is like \\D in perl.
proto::terminal<detail::posix_charset_placeholder>::type const _d = {{"d", false}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches a space character.
///
/// '_s' matches a single space character. The regex traits are used to determine which
/// characters are space characters. Use ~_s to match a character that is not a space
/// character.
///
/// \attention _s is like \\s in perl. ~_s is like \\S in perl.
proto::terminal<detail::posix_charset_placeholder>::type const _s = {{"s", false}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches a literal newline character, '\\n'.
///
/// '_n' matches a single newline character, '\\n'. Use ~_n to match a character
/// that is not a newline.
///
/// \attention ~_n is like '.' in perl without the /s modifier.
proto::terminal<char>::type const _n = {'\n'};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches a logical newline sequence.
///
/// '_ln' matches a logical newline sequence. This can be any character in the
/// line separator class, as determined by the regex traits, or the '\\r\\n' sequence.
/// For the purpose of back-tracking, '\\r\\n' is treated as a unit.
/// To match any one character that is not a logical newline, use ~_ln.
detail::logical_newline_xpression const _ln = {{}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Matches any one character.
///
/// Match any character, similar to '.' in perl syntax with the /s modifier.
/// '_' matches any one character, including the newline.
///
/// \attention To match any character except the newline, use ~_n
proto::terminal<detail::any_matcher>::type const _ = {{}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Reference to the current regex object
///
/// Useful when constructing recursive regular expression objects. The 'self'
/// identifier is a short-hand for the current regex object. For instance,
/// sregex rx = '(' >> (self | nil) >> ')'; will create a regex object that
/// matches balanced parens such as "((()))".
proto::terminal<detail::self_placeholder>::type const self = {{}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Used to create character sets.
///
/// There are two ways to create character sets with the 'set' identifier. The
/// easiest is to create a comma-separated list of the characters in the set,
/// as in (set= 'a','b','c'). This set will match 'a', 'b', or 'c'. The other
/// way is to define the set as an argument to the set subscript operator.
/// For instance, set[ 'a' | range('b','c') | digit ] will match an 'a', 'b',
/// 'c' or a digit character.
///
/// To complement a set, apply the '~' operator. For instance, ~(set= 'a','b','c')
/// will match any character that is not an 'a', 'b', or 'c'.
///
/// Sets can be composed of other, possibly complemented, sets. For instance,
/// set[ ~digit | ~(set= 'a','b','c') ].
detail::set_initializer_type const set = {{}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Sub-match placeholder type, used to create named captures in
/// static regexes.
///
/// \c mark_tag is the type of the global sub-match placeholders \c s0, \c s1, etc.. You
/// can use the \c mark_tag type to create your own sub-match placeholders with
/// more meaningful names. This is roughly equivalent to the "named capture"
/// feature of dynamic regular expressions.
///
/// To create a named sub-match placeholder, initialize it with a unique integer.
/// The integer must only be unique within the regex in which the placeholder
/// is used. Then you can use it within static regexes to created sub-matches
/// by assigning a sub-expression to it, or to refer back to already created
/// sub-matches.
///
/// \code
/// mark_tag number(1); // "number" is now equivalent to "s1"
/// // Match a number, followed by a space and the same number again
/// sregex rx = (number = +_d) >> ' ' >> number;
/// \endcode
///
/// After a successful \c regex_match() or \c regex_search(), the sub-match placeholder
/// can be used to index into the <tt>match_results\<\></tt> object to retrieve the
/// corresponding sub-match.
struct mark_tag
: proto::extends<detail::basic_mark_tag, mark_tag, detail::regex_domain>
{
private:
typedef proto::extends<detail::basic_mark_tag, mark_tag, detail::regex_domain> base_type;
static detail::basic_mark_tag make_tag(int mark_nbr)
{
detail::basic_mark_tag mark = {{mark_nbr}};
return mark;
}
public:
/// \brief Initialize a mark_tag placeholder
/// \param mark_nbr An integer that uniquely identifies this \c mark_tag
/// within the static regexes in which this \c mark_tag will be used.
/// \pre <tt>mark_nbr \> 0</tt>
mark_tag(int mark_nbr)
: base_type(mark_tag::make_tag(mark_nbr))
{
// Marks numbers must be integers greater than 0.
BOOST_ASSERT(mark_nbr > 0);
}
/// INTERNAL ONLY
operator detail::basic_mark_tag const &() const
{
return this->proto_base();
}
BOOST_PROTO_EXTENDS_USING_ASSIGN_NON_DEPENDENT(mark_tag)
};
// This macro is used when declaring mark_tags that are global because
// it guarantees that they are statically initialized. That avoids
// order-of-initialization bugs. In user code, the simpler: mark_tag s0(0);
// would be preferable.
/// INTERNAL ONLY
#define BOOST_XPRESSIVE_GLOBAL_MARK_TAG(NAME, VALUE) \
boost::xpressive::mark_tag::proto_base_expr const NAME = {{VALUE}} \
/**/
///////////////////////////////////////////////////////////////////////////////
/// \brief Sub-match placeholder, like $& in Perl
BOOST_XPRESSIVE_GLOBAL_MARK_TAG(s0, 0);
///////////////////////////////////////////////////////////////////////////////
/// \brief Sub-match placeholder, like $1 in perl.
///
/// To create a sub-match, assign a sub-expression to the sub-match placeholder.
/// For instance, (s1= _) will match any one character and remember which
/// character was matched in the 1st sub-match. Later in the pattern, you can
/// refer back to the sub-match. For instance, (s1= _) >> s1 will match any
/// character, and then match the same character again.
///
/// After a successful regex_match() or regex_search(), the sub-match placeholders
/// can be used to index into the match_results\<\> object to retrieve the Nth
/// sub-match.
BOOST_XPRESSIVE_GLOBAL_MARK_TAG(s1, 1);
BOOST_XPRESSIVE_GLOBAL_MARK_TAG(s2, 2);
BOOST_XPRESSIVE_GLOBAL_MARK_TAG(s3, 3);
BOOST_XPRESSIVE_GLOBAL_MARK_TAG(s4, 4);
BOOST_XPRESSIVE_GLOBAL_MARK_TAG(s5, 5);
BOOST_XPRESSIVE_GLOBAL_MARK_TAG(s6, 6);
BOOST_XPRESSIVE_GLOBAL_MARK_TAG(s7, 7);
BOOST_XPRESSIVE_GLOBAL_MARK_TAG(s8, 8);
BOOST_XPRESSIVE_GLOBAL_MARK_TAG(s9, 9);
// NOTE: For the purpose of xpressive's documentation, make icase() look like an
// ordinary function. In reality, it is a function object defined in detail/icase.hpp
// so that it can serve double-duty as regex_constants::icase, the syntax_option_type.
#ifdef BOOST_XPRESSIVE_DOXYGEN_INVOKED
///////////////////////////////////////////////////////////////////////////////
/// \brief Makes a sub-expression case-insensitive.
///
/// Use icase() to make a sub-expression case-insensitive. For instance,
/// "foo" >> icase(set['b'] >> "ar") will match "foo" exactly followed by
/// "bar" irrespective of case.
template<typename Expr> detail::unspecified icase(Expr const &expr) { return 0; }
#endif
///////////////////////////////////////////////////////////////////////////////
/// \brief Makes a literal into a regular expression.
///
/// Use as_xpr() to turn a literal into a regular expression. For instance,
/// "foo" >> "bar" will not compile because both operands to the right-shift
/// operator are const char*, and no such operator exists. Use as_xpr("foo") >> "bar"
/// instead.
///
/// You can use as_xpr() with character literals in addition to string literals.
/// For instance, as_xpr('a') will match an 'a'. You can also complement a
/// character literal, as with ~as_xpr('a'). This will match any one character
/// that is not an 'a'.
#ifdef BOOST_XPRESSIVE_DOXYGEN_INVOKED
template<typename Literal> detail::unspecified as_xpr(Literal const &literal) { return 0; }
#else
proto::functional::as_expr<> const as_xpr = {};
#endif
///////////////////////////////////////////////////////////////////////////////
/// \brief Embed a regex object by reference.
///
/// \param rex The basic_regex object to embed by reference.
template<typename BidiIter>
inline typename proto::terminal<reference_wrapper<basic_regex<BidiIter> const> >::type const
by_ref(basic_regex<BidiIter> const &rex)
{
reference_wrapper<basic_regex<BidiIter> const> ref(rex);
return proto::terminal<reference_wrapper<basic_regex<BidiIter> const> >::type::make(ref);
}
///////////////////////////////////////////////////////////////////////////////
/// \brief Match a range of characters.
///
/// Match any character in the range [ch_min, ch_max].
///
/// \param ch_min The lower end of the range to match.
/// \param ch_max The upper end of the range to match.
template<typename Char>
inline typename proto::terminal<detail::range_placeholder<Char> >::type const
range(Char ch_min, Char ch_max)
{
detail::range_placeholder<Char> that = {ch_min, ch_max, false};
return proto::terminal<detail::range_placeholder<Char> >::type::make(that);
}
///////////////////////////////////////////////////////////////////////////////
/// \brief Make a sub-expression optional. Equivalent to !as_xpr(expr).
///
/// \param expr The sub-expression to make optional.
template<typename Expr>
typename proto::result_of::make_expr<
proto::tag::logical_not
, proto::default_domain
, Expr const &
>::type const
optional(Expr const &expr)
{
return proto::make_expr<
proto::tag::logical_not
, proto::default_domain
>(boost::ref(expr));
}
///////////////////////////////////////////////////////////////////////////////
/// \brief Repeat a sub-expression multiple times.
///
/// There are two forms of the repeat\<\>() function template. To match a
/// sub-expression N times, use repeat\<N\>(expr). To match a sub-expression
/// from M to N times, use repeat\<M,N\>(expr).
///
/// The repeat\<\>() function creates a greedy quantifier. To make the quantifier
/// non-greedy, apply the unary minus operator, as in -repeat\<M,N\>(expr).
///
/// \param expr The sub-expression to repeat.
template<unsigned int Min, unsigned int Max, typename Expr>
typename proto::result_of::make_expr<
detail::generic_quant_tag<Min, Max>
, proto::default_domain
, Expr const &
>::type const
repeat(Expr const &expr)
{
return proto::make_expr<
detail::generic_quant_tag<Min, Max>
, proto::default_domain
>(boost::ref(expr));
}
/// \overload
///
template<unsigned int Count, typename Expr2>
typename proto::result_of::make_expr<
detail::generic_quant_tag<Count, Count>
, proto::default_domain
, Expr2 const &
>::type const
repeat(Expr2 const &expr2)
{
return proto::make_expr<
detail::generic_quant_tag<Count, Count>
, proto::default_domain
>(boost::ref(expr2));
}
///////////////////////////////////////////////////////////////////////////////
/// \brief Create an independent sub-expression.
///
/// Turn off back-tracking for a sub-expression. Any branches or repeats within
/// the sub-expression will match only one way, and no other alternatives are
/// tried.
///
/// \attention keep(expr) is equivalent to the perl (?>...) extension.
///
/// \param expr The sub-expression to modify.
template<typename Expr>
typename proto::result_of::make_expr<
detail::keeper_tag
, proto::default_domain
, Expr const &
>::type const
keep(Expr const &expr)
{
return proto::make_expr<
detail::keeper_tag
, proto::default_domain
>(boost::ref(expr));
}
///////////////////////////////////////////////////////////////////////////////
/// \brief Look-ahead assertion.
///
/// before(expr) succeeds if the expr sub-expression would match at the current
/// position in the sequence, but expr is not included in the match. For instance,
/// before("foo") succeeds if we are before a "foo". Look-ahead assertions can be
/// negated with the bit-compliment operator.
///
/// \attention before(expr) is equivalent to the perl (?=...) extension.
/// ~before(expr) is a negative look-ahead assertion, equivalent to the
/// perl (?!...) extension.
///
/// \param expr The sub-expression to put in the look-ahead assertion.
template<typename Expr>
typename proto::result_of::make_expr<
detail::lookahead_tag
, proto::default_domain
, Expr const &
>::type const
before(Expr const &expr)
{
return proto::make_expr<
detail::lookahead_tag
, proto::default_domain
>(boost::ref(expr));
}
///////////////////////////////////////////////////////////////////////////////
/// \brief Look-behind assertion.
///
/// after(expr) succeeds if the expr sub-expression would match at the current
/// position minus N in the sequence, where N is the width of expr. expr is not included in
/// the match. For instance, after("foo") succeeds if we are after a "foo". Look-behind
/// assertions can be negated with the bit-complement operator.
///
/// \attention after(expr) is equivalent to the perl (?<=...) extension.
/// ~after(expr) is a negative look-behind assertion, equivalent to the
/// perl (?<!...) extension.
///
/// \param expr The sub-expression to put in the look-ahead assertion.
///
/// \pre expr cannot match a variable number of characters.
template<typename Expr>
typename proto::result_of::make_expr<
detail::lookbehind_tag
, proto::default_domain
, Expr const &
>::type const
after(Expr const &expr)
{
return proto::make_expr<
detail::lookbehind_tag
, proto::default_domain
>(boost::ref(expr));
}
///////////////////////////////////////////////////////////////////////////////
/// \brief Specify a regex traits or a std::locale.
///
/// imbue() instructs the regex engine to use the specified traits or locale
/// when matching the regex. The entire expression must use the same traits/locale.
/// For instance, the following specifies a locale for use with a regex:
/// std::locale loc;
/// sregex rx = imbue(loc)(+digit);
///
/// \param loc The std::locale or regex traits object.
template<typename Locale>
inline detail::modifier_op<detail::locale_modifier<Locale> > const
imbue(Locale const &loc)
{
detail::modifier_op<detail::locale_modifier<Locale> > mod =
{
detail::locale_modifier<Locale>(loc)
, regex_constants::ECMAScript
};
return mod;
}
proto::terminal<detail::attribute_placeholder<mpl::int_<1> > >::type const a1 = {{}};
proto::terminal<detail::attribute_placeholder<mpl::int_<2> > >::type const a2 = {{}};
proto::terminal<detail::attribute_placeholder<mpl::int_<3> > >::type const a3 = {{}};
proto::terminal<detail::attribute_placeholder<mpl::int_<4> > >::type const a4 = {{}};
proto::terminal<detail::attribute_placeholder<mpl::int_<5> > >::type const a5 = {{}};
proto::terminal<detail::attribute_placeholder<mpl::int_<6> > >::type const a6 = {{}};
proto::terminal<detail::attribute_placeholder<mpl::int_<7> > >::type const a7 = {{}};
proto::terminal<detail::attribute_placeholder<mpl::int_<8> > >::type const a8 = {{}};
proto::terminal<detail::attribute_placeholder<mpl::int_<9> > >::type const a9 = {{}};
///////////////////////////////////////////////////////////////////////////////
/// \brief Specify which characters to skip when matching a regex.
///
/// <tt>skip()</tt> instructs the regex engine to skip certain characters when matching
/// a regex. It is most useful for writing regexes that ignore whitespace.
/// For instance, the following specifies a regex that skips whitespace and
/// punctuation:
///
/// \code
/// // A sentence is one or more words separated by whitespace
/// // and punctuation.
/// sregex word = +alpha;
/// sregex sentence = skip(set[_s | punct])( +word );
/// \endcode
///
/// The way it works in the above example is to insert
/// <tt>keep(*set[_s | punct])</tt> before each primitive within the regex.
/// A "primitive" includes terminals like strings, character sets and nested
/// regexes. A final <tt>*set[_s | punct]</tt> is added to the end of the
/// regex. The regex <tt>sentence</tt> specified above is equivalent to
/// the following:
///
/// \code
/// sregex sentence = +( keep(*set[_s | punct]) >> word )
/// >> *set[_s | punct];
/// \endcode
///
/// \attention Skipping does not affect how nested regexes are handled because
/// they are treated atomically. String literals are also treated
/// atomically; that is, no skipping is done within a string literal. So
/// <tt>skip(_s)("this that")</tt> is not the same as
/// <tt>skip(_s)("this" >> as_xpr("that"))</tt>. The first will only match
/// when there is only one space between "this" and "that". The second will
/// skip any and all whitespace between "this" and "that".
///
/// \param skip A regex that specifies which characters to skip.
template<typename Skip>
detail::skip_directive<Skip> skip(Skip const &skip)
{
return detail::skip_directive<Skip>(skip);
}
namespace detail
{
inline void ignore_unused_regex_primitives()
{
detail::ignore_unused(repeat_max);
detail::ignore_unused(inf);
detail::ignore_unused(epsilon);
detail::ignore_unused(nil);
detail::ignore_unused(alnum);
detail::ignore_unused(bos);
detail::ignore_unused(eos);
detail::ignore_unused(bol);
detail::ignore_unused(eol);
detail::ignore_unused(bow);
detail::ignore_unused(eow);
detail::ignore_unused(_b);
detail::ignore_unused(_w);
detail::ignore_unused(_d);
detail::ignore_unused(_s);
detail::ignore_unused(_n);
detail::ignore_unused(_ln);
detail::ignore_unused(_);
detail::ignore_unused(self);
detail::ignore_unused(set);
detail::ignore_unused(s0);
detail::ignore_unused(s1);
detail::ignore_unused(s2);
detail::ignore_unused(s3);
detail::ignore_unused(s4);
detail::ignore_unused(s5);
detail::ignore_unused(s6);
detail::ignore_unused(s7);
detail::ignore_unused(s8);
detail::ignore_unused(s9);
detail::ignore_unused(a1);
detail::ignore_unused(a2);
detail::ignore_unused(a3);
detail::ignore_unused(a4);
detail::ignore_unused(a5);
detail::ignore_unused(a6);
detail::ignore_unused(a7);
detail::ignore_unused(a8);
detail::ignore_unused(a9);
detail::ignore_unused(as_xpr);
}
}
}} // namespace boost::xpressive
#endif