Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Match a repeating number of elements.
Defined in header <boost/url/grammar/range_rule.hpp>
template< class Rule> constexpr implementation-defined range_rule( Rule next, std::size_t N = 0, std::size_t M = std::size_t(-1));
Elements are matched using the passed rule.
Normally when the rule returns an error, the range ends and the input is
rewound to one past the last character that matched successfully. However,
if the rule returns the special value error::end_of_range, the input is not
rewound. This allows for rules which consume input without producing elements
in the range. For example, to relax the grammar for a comma-delimited list
by allowing extra commas in between elements.
using value_type = range< typename Rule::value_type >;
Rules are used with the function parse.
// range = 1*( ";" token ) system::result< range<core::string_view> > rv = parse( ";alpha;xray;charlie" , range_rule( tuple_rule( squelch( delim_rule( ';' ) ), token_rule( alpha_chars ) ), 1 ) );
range = <N>*<M>next
|
Name |
Description |
|---|---|
|
|
The rule to use for matching each element. The range extends until this rule returns an error. |
|
|
The minimum number of elements for the range to be valid. If omitted, this defaults to zero. |
|
|
The maximum number of elements for the range to be valid. If omitted, this defaults to unlimited. |
alpha_chars, delim_rule, error::end_of_range, parse, range, tuple_rule, squelch.
Convenience header <boost/url/grammar.hpp>