regex101: PCRE2 (PHP) Match Workspace

Pro

\Astart of string

Non-Capturing Group(?:\s*^(?:#\w+.*\s*|extern\s+.+)$)*+

*+repeats the group contents below any number of times:

\s*any whitespace character, repeated any number of times

^start of line

Non-Capturing Group(?:#\w+.*\s*|extern\s+.+)

1st Alternative#\w+.*\s*

#the literal # (35₁₀ / 43₈ / 23₁₆)

\w+any word character, repeated at least once

.*any character (except for line terminators), repeated any number of times

\s*any whitespace character, repeated any number of times

2nd Alternativeextern\s+.+

externthe literal text extern (case sensitive)

\s+any whitespace character, repeated at least once

.+any character (except for line terminators), repeated at least once

$end of line

Group namespace(?<namespace>\s*namespace(?:\s+utTestNamespace\s*(?>(?<block>{(?:[^{}]*(?&block)*)*}))|(\s*[\w:]*\s*{)(?&namespace)\s*}))

\s*any whitespace character, repeated any number of times

namespacethe literal text namespace (case sensitive)

Non-Capturing Group(?:\s+utTestNamespace\s*(?>(?<block>{(?:[^{}]*(?&block)*)*}))|(\s*[\w:]*\s*{)(?&namespace)\s*})

1st Alternative\s+utTestNamespace\s*(?>(?<block>{(?:[^{}]*(?&block)*)*}))

\s+any whitespace character, repeated at least once

utTestNamespacethe literal text utTestNamespace (case sensitive)

\s*any whitespace character, repeated any number of times

Atomic Group(?>(?<block>{(?:[^{}]*(?&block)*)*}))

Group block(?<block>{(?:[^{}]*(?&block)*)*})

{the literal { (123₁₀ / 173₈ / 7B₁₆)

Non-Capturing Group(?:[^{}]*(?&block)*)*

*repeats the group contents below any number of times:

Negated Character Class[^{}]*

*matches any number of characters outside the set below:

{the literal { (123₁₀ / 173₈ / 7B₁₆)

}the literal } (125₁₀ / 175₈ / 7D₁₆)

(?&block)*calls group block as a subroutine, repeated any number of times

}the literal } (125₁₀ / 175₈ / 7D₁₆)

2nd Alternative(\s*[\w:]*\s*{)(?&namespace)\s*}

Group 3(\s*[\w:]*\s*{)

\s*any whitespace character, repeated any number of times

Character Class[\w:]*

*matches any number of characters from the set below:

\wany word character

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\s*any whitespace character, repeated any number of times

{the literal { (123₁₀ / 173₈ / 7B₁₆)

(?&namespace)calls group namespace as a subroutine

\s*any whitespace character, repeated any number of times

}the literal } (125₁₀ / 175₈ / 7D₁₆)

\s*any whitespace character, repeated any number of times

\zend of string

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

25 tokens

Regular Expression

\A(?:\s*^(?:#\w+.*\s*|extern\s+.+)$)*+(?<namespace>\s*namespace(?:\s+utTestNamespace\s*(?>(?<block>{(?:[^{}]*(?&block)*)*}))|(\s*[\w:]*\s*{)(?&namespace)\s*}))\s*\z

New

#include <memory>
#include <vector>
#include <gtest/gtest.h>

namespace utTestNamespace
{
using ::testing::NiceMock;
# some code here
}

Extraction

#include <memory>
#include <vector>
#include <gtest/gtest.h>

namespace utTestNamespace
{
using ::testing::NiceMock;
# some code here
}