正则表达式以匹配文件中的特定功能及其参数 [英] Regex to match specific functions and their arguments in files
问题描述
我正在使用gettext javascript解析器，并且卡在正则表达式中.
I'm working on a gettext javascript parser and I'm stuck on the parsing regex.
我需要捕获传递给特定方法调用_n(和_(的每个参数.例如，如果我的javascript文件中包含以下内容:
I need to catch every argument passed to a specific method call _n( and _(. For example, if I have these in my javascript files:
_("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..
这引用了本文档: http://poedit.net/trac/wiki/Doc/Keywords
我计划分两次(和两个正则表达式)进行操作:
I'm planning in doing it in two times (and two regex):
- 捕获
_n(或_(方法调用的所有函数参数 - 只抓紧细线
- catch all function arguments for
_n(or_(method calls - catch the stringy ones only
基本上，我想要一个正则表达式，它可以说捕获_n(或_(之后的所有内容，并在功能完成后实际上在最后一个括号)停止 .我不知道如果可以使用正则表达式而没有javascript解析器.
Basically, I'd like a Regex that could say "catch everything after _n( or _( and stop at the last parenthesis ) actually when the function is done. I dunno if it is possible with regex and without a javascript parser.
还可以做的是在_n(或_(之后捕获每个"字符串"或字符串"，并在行的结尾处停止，或者在新的_n(或_(字符的开头停止
What could also be done is "catch every "string" or 'string' after _n( or _( and stop at the end of the line OR at the beginning of a new _n( or _( character.
在我做的所有事情中，我要么被卡在_( "one (optional)" );上并带有内括号，要么被卡在apples === 0 ? _( "No apples" ) : _n("%1 apple", "%1 apples", apples)上并且在同一行上有两次调用.
In everything I've done I get either stuck on _( "one (optional)" ); with its inside parenthesis or apples === 0 ? _( "No apples" ) : _n("%1 apple", "%1 apples", apples) with two calls on the same line.
这是我到目前为止使用不完善的正则表达式实现的内容: javascript一个或把手一
Here is what I implemented so far, with un-perfect regex: a generic parser and the javascript one or the handlebars one
推荐答案
注意: 如果您不熟悉递归，请阅读此答案.
Note: Read this answer if you're not familiar with recursion.
第1部分:匹配特定功能
谁说正则表达式不能模块化? PCRE正则表达式可助您一臂之力！
Part 1: match specific functions
Who said that regex can't be modular? Well PCRE regex to the rescue!
~ # 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，并且x修饰符用于此花哨的空格和对正则表达式的注释.
The s is for matching newlines with . and the x modifier is for this fancy spacing and commenting of our regex.
由于我们的正则表达式也将获得左括号和右括号()，因此我们可能需要对其进行过滤.我们将在结果上使用preg_replace()
Since our regex will also get the opening and closing brackets (), we might need to filter them. We will use preg_replace() on the results:
~ # 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
所以这是另一个模块化正则表达式，您甚至可以添加自己的语法:
So here's another modular regex, you could even add your own grammar:
~ # 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
我们将循环并使用preg_match_all().最终代码如下所示:
We will loop and use preg_match_all(). The final code would look like this:
$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';
}
您可能想创建一个递归函数来生成完整的树. 查看此答案.
You might want to create a recursive function to generate a full tree. See this answer.
您可能会注意到function(){}部分没有正确解析.我将其作为读者的练习:)
You might notice that the function(){} part isn't parsed correctly. I will let that as an exercise for the readers :)
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