注意： Read this answer 如果您不熟悉递归。
第 1 部分：匹配特定功能
谁说正则表达式不能模块化？好吧 PCRE 正则表达式来救援！
~ # Delimiter
(?(DEFINE) # Start of definitions
(?P<str_double_quotes>
(?<!\\) # Not escaped
" # Match a double quote
(?: # Non-capturing group
[^\\] # Match anything not a backslash
| # Or
\\. # Match a backslash and a single character (ie: an escaped character)
)*? # Repeat the non-capturing group zero or more times, ungreedy/lazy
" # Match the ending double quote
)
(?P<str_single_quotes>
(?<!\\) # Not escaped
' # Match a single quote
(?: # Non-capturing group
[^\\] # Match anything not a backslash
| # Or
\\. # Match a backslash and a single character (ie: an escaped character)
)*? # Repeat the non-capturing group zero or more times, ungreedy/lazy
' # Match the ending single quote
)
(?P<brackets>
\( # Match an opening bracket
(?: # A non capturing group
(?&str_double_quotes) # Recurse/use the str_double_quotes pattern
| # Or
(?&str_single_quotes) # Recurse/use the str_single_quotes pattern
| # Or
[^()] # Anything not a bracket
| # Or
(?&brackets) # Recurse the bracket pattern
)*
\)
)
) # End of definitions
# Let's start matching for real now:
_n? # Match _ or _n
\s* # Optional white spaces
(?P<results>(?&brackets)) # Recurse/use the brackets pattern and put it in the results group
~sx
s 用于将换行符与. 匹配，x 修饰符用于我们正则表达式的这种花哨的间距和注释。
Online regex demo
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第 2 部分：去掉左括号和右括号
由于我们的正则表达式也会得到左括号和右括号()，我们可能需要过滤它们。我们将在结果上使用preg_replace()：
~ # Delimiter
^ # Assert begin of string
\( # Match an opening bracket
\s* # Match optional whitespaces
| # Or
\s* # Match optional whitespaces
\) # Match a closing bracket
$ # Assert end of string
~x
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第 3 部分：提取参数
这是另一个模块化的正则表达式，您甚至可以添加自己的语法：
~ # Delimiter
(?(DEFINE) # Start of definitions
(?P<str_double_quotes>
(?<!\\) # Not escaped
" # Match a double quote
(?: # Non-capturing group
[^\\] # Match anything not a backslash
| # Or
\\. # Match a backslash and a single character (ie: an escaped character)
)*? # Repeat the non-capturing group zero or more times, ungreedy/lazy
" # Match the ending double quote
)
(?P<str_single_quotes>
(?<!\\) # Not escaped
' # Match a single quote
(?: # Non-capturing group
[^\\] # Match anything not a backslash
| # Or
\\. # Match a backslash and a single character (ie: an escaped character)
)*? # Repeat the non-capturing group zero or more times, ungreedy/lazy
' # Match the ending single quote
)
(?P<array>
Array\s*
(?&brackets)
)
(?P<variable>
[^\s,()]+ # I don't know the exact grammar for a variable in ECMAScript
)
(?P<brackets>
\( # Match an opening bracket
(?: # A non capturing group
(?&str_double_quotes) # Recurse/use the str_double_quotes pattern
| # Or
(?&str_single_quotes) # Recurse/use the str_single_quotes pattern
| # Or
(?&array) # Recurse/use the array pattern
| # Or
(?&variable) # Recurse/use the array pattern
| # Or
[^()] # Anything not a bracket
| # Or
(?&brackets) # Recurse the bracket pattern
)*
\)
)
) # End of definitions
# Let's start matching for real now:
(?&array)
|
(?&variable)
|
(?&str_double_quotes)
|
(?&str_single_quotes)
~xis
我们将循环使用preg_match_all()。最终代码如下所示：
$functionPattern = <<<'regex'
~ # Delimiter
(?(DEFINE) # Start of definitions
(?P<str_double_quotes>
(?<!\\) # Not escaped
" # Match a double quote
(?: # Non-capturing group
[^\\] # Match anything not a backslash
| # Or
\\. # Match a backslash and a single character (ie: an escaped character)
)*? # Repeat the non-capturing group zero or more times, ungreedy/lazy
" # Match the ending double quote
)
(?P<str_single_quotes>
(?<!\\) # Not escaped
' # Match a single quote
(?: # Non-capturing group
[^\\] # Match anything not a backslash
| # Or
\\. # Match a backslash and a single character (ie: an escaped character)
)*? # Repeat the non-capturing group zero or more times, ungreedy/lazy
' # Match the ending single quote
)
(?P<brackets>
\( # Match an opening bracket
(?: # A non capturing group
(?&str_double_quotes) # Recurse/use the str_double_quotes pattern
| # Or
(?&str_single_quotes) # Recurse/use the str_single_quotes pattern
| # Or
[^()] # Anything not a bracket
| # Or
(?&brackets) # Recurse the bracket pattern
)*
\)
)
) # End of definitions
# Let's start matching for real now:
_n? # Match _ or _n
\s* # Optional white spaces
(?P<results>(?&brackets)) # Recurse/use the brackets pattern and put it in the results group
~sx
regex;
$argumentsPattern = <<<'regex'
~ # Delimiter
(?(DEFINE) # Start of definitions
(?P<str_double_quotes>
(?<!\\) # Not escaped
" # Match a double quote
(?: # Non-capturing group
[^\\] # Match anything not a backslash
| # Or
\\. # Match a backslash and a single character (ie: an escaped character)
)*? # Repeat the non-capturing group zero or more times, ungreedy/lazy
" # Match the ending double quote
)
(?P<str_single_quotes>
(?<!\\) # Not escaped
' # Match a single quote
(?: # Non-capturing group
[^\\] # Match anything not a backslash
| # Or
\\. # Match a backslash and a single character (ie: an escaped character)
)*? # Repeat the non-capturing group zero or more times, ungreedy/lazy
' # Match the ending single quote
)
(?P<array>
Array\s*
(?&brackets)
)
(?P<variable>
[^\s,()]+ # I don't know the exact grammar for a variable in ECMAScript
)
(?P<brackets>
\( # Match an opening bracket
(?: # A non capturing group
(?&str_double_quotes) # Recurse/use the str_double_quotes pattern
| # Or
(?&str_single_quotes) # Recurse/use the str_single_quotes pattern
| # Or
(?&array) # Recurse/use the array pattern
| # Or
(?&variable) # Recurse/use the array pattern
| # Or
[^()] # Anything not a bracket
| # Or
(?&brackets) # Recurse the bracket pattern
)*
\)
)
) # End of definitions
# Let's start matching for real now:
(?&array)
|
(?&str_double_quotes)
|
(?&str_single_quotes)
|
(?&variable)
~six
regex;
$input = <<<'input'
_ ("foo") // want "foo"
_n("bar", "baz", 42); // want "bar", "baz", 42
_n(domain, "bux", var); // want domain, "bux", var
_( "one (optional)" ); // want "one (optional)"
apples === 0 ? _( "No apples" ) : _n("%1 apple", "%1 apples", apples) // could have on the same line two calls..
// misleading cases
_n("foo (")
_n("foo (\)", 'foo)', aa)
_n( Array(1, 2, 3), Array(")", '(') );
_n(function(foo){return foo*2;}); // Is this even valid?
_n (); // Empty
_ (
"Foo",
'Bar',
Array(
"wow",
"much",
'whitespaces'
),
multiline
); // PCRE is awesome
input;
if(preg_match_all($functionPattern, $input, $m)){
$filtered = preg_replace(
'~ # Delimiter
^ # Assert begin of string
\( # Match an opening bracket
\s* # Match optional whitespaces
| # Or
\s* # Match optional whitespaces
\) # Match a closing bracket
$ # Assert end of string
~x', // Regex
'', // Replace with nothing
$m['results'] // Subject
); // Getting rid of opening & closing brackets
// Part 3: extract arguments:
$parsedTree = array();
foreach($filtered as $arguments){ // Loop
if(preg_match_all($argumentsPattern, $arguments, $m)){ // If there's a match
$parsedTree[] = array(
'all_arguments' => $arguments,
'branches' => $m[0]
); // Add an array to our tree and fill it
}else{
$parsedTree[] = array(
'all_arguments' => $arguments,
'branches' => array()
); // Add an array with empty branches
}
}
print_r($parsedTree); // Let's see the results;
}else{
echo 'no matches';
}
Online php demo
您可能想要创建一个递归函数来生成一棵完整的树。 See this answer.
您可能会注意到function(){} 部分未正确解析。我会把它作为读者的练习:)