#include <x/pcre.H> std::string line; x::pcre pattern=x::pcre::create("(.*) (.*)"); std::vector<std::string_view> patterns=pattern->match("abra cadabra"); if (patterns.size() == 3) process_words(patterns[1], patterns[2]);
This is a Perl-compatible regular expression engine, a facade for the PCRE2 library.
x::pcre
is a reference to a reference-counted
object that specifies a regular expression.
The create() constructor throws an exception if
the given regular expression's syntax is malformed.
create() takes an optional second argument,
an uint32_t of option flags, see
pcre2_compile(3)
for a list of available option flags.
Once compiled, match() checks if the string
matches a regular expression. match() takes
two optional arguments:
Starting index to search, this defaults to 0.
Options for pcre2_match(3).
An empty vector gets returned if the match fails. A successful
regular expression match
returns a non-empty vector of
std::string_view. The first one is the matched
regular expression. Sub-patterns (as specified by the regular expression)
get returned as additional values.
The search string parameter must be an lvalue, and cannot be a temporary
rvalue. The
string views are views into the exact location in the original string.
As such, each string view's data() gives
the exact location in the passed-in string where the regular expression
was matched.
std::vector<std::vector<std::string_view>> patterns=pattern->match_all("abra cadabra");
There's also a match_all() that returns a vector
of std::string_view vectors.
match_all() repeatedly invokes
match() to find every occurence of the regular
expression in the searched string.
An error from the underlying PCRE library can result in a thrown exception. The caller should catch any thrown exceptions, and decide what to do with them.