71 lines
No EOL
1.5 KiB
JavaScript
71 lines
No EOL
1.5 KiB
JavaScript
/**
|
|
* The MIT License (MIT)
|
|
* Copyright (c) 2017-present Dmitry Soshnikov <dmitry.soshnikov@gmail.com>
|
|
*/
|
|
|
|
'use strict';
|
|
|
|
/**
|
|
* A regexp-tree plugin to replace single char character classes with
|
|
* just that character.
|
|
*
|
|
* [\d] -> \d, [^\w] -> \W
|
|
*/
|
|
|
|
module.exports = {
|
|
CharacterClass: function CharacterClass(path) {
|
|
var node = path.node;
|
|
|
|
|
|
if (node.expressions.length !== 1 || !isAppropriateChar(node.expressions[0])) {
|
|
return;
|
|
}
|
|
|
|
var _node$expressions$ = node.expressions[0],
|
|
value = _node$expressions$.value,
|
|
kind = _node$expressions$.kind,
|
|
escaped = _node$expressions$.escaped;
|
|
|
|
|
|
if (node.negative) {
|
|
// For negative can extract only meta chars like [^\w] -> \W
|
|
// cannot do for [^a] -> a (wrong).
|
|
if (!isMeta(value)) {
|
|
return;
|
|
}
|
|
|
|
value = getInverseMeta(value);
|
|
}
|
|
|
|
path.replace({
|
|
type: 'Char',
|
|
value: value,
|
|
kind: kind,
|
|
escaped: escaped || shouldEscape(value)
|
|
});
|
|
}
|
|
};
|
|
|
|
function isAppropriateChar(node) {
|
|
return node.type === 'Char' &&
|
|
// We don't extract [\b] (backspace) since \b has different
|
|
// semantics (word boundary).
|
|
node.value !== '\\b';
|
|
}
|
|
|
|
function isMeta(value) {
|
|
return (/^\\[dwsDWS]$/.test(value)
|
|
);
|
|
}
|
|
|
|
function getInverseMeta(value) {
|
|
return (/[dws]/.test(value) ? value.toUpperCase() : value.toLowerCase()
|
|
);
|
|
}
|
|
|
|
// Note: \{ and \} are always preserved to avoid `a[{]2[}]` turning
|
|
// into `a{2}`.
|
|
function shouldEscape(value) {
|
|
return (/[*[()+?$./{}|]/.test(value)
|
|
);
|
|
} |