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Avoid matching surrogate halves when lone surrogates are to be matched
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Fixes #28.
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@mathiasbynens
mathiasbynens committed Jan 24, 2015
1 parent 216a51a commit 905301d
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6 changes: 3 additions & 3 deletions README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -160,13 +160,13 @@ regenerate()
.addRange(0x000000, 0x10FFFF) // add all Unicode code points
.removeRange('A', 'z') // remove all symbols from `A` to `z`
.toString();
// → '[\\0-@\\{-\\uD7FF\\uDC00-\\uFFFF]|[\\uD800-\\uDBFF][\\uDC00-\\uDFFF]|[\\uD800-\\uDBFF]'
// → '[\\0-@\\{-\\uD7FF\\uE000-\\uFFFF]|[\\uD800-\\uDBFF][\\uDC00-\\uDFFF]|[\\uD800-\\uDBFF](?![\\uDC00-\\uDFFF])|(?:[^\\uD800-\\uDBFF]|^)[\\uDC00-\\uDFFF]'

regenerate()
.addRange(0x000000, 0x10FFFF) // add all Unicode code points
.removeRange(0x0041, 0x007A) // remove all code points from U+0041 to U+007A
.toString();
// → '[\\0-@\\{-\\uD7FF\\uDC00-\\uFFFF]|[\\uD800-\\uDBFF][\\uDC00-\\uDFFF]|[\\uD800-\\uDBFF]'
// → '[\\0-@\\{-\\uD7FF\\uE000-\\uFFFF]|[\\uD800-\\uDBFF][\\uDC00-\\uDFFF]|[\\uD800-\\uDBFF](?![\\uDC00-\\uDFFF])|(?:[^\\uD800-\\uDBFF]|^)[\\uDC00-\\uDFFF]'
```

### `regenerate.prototype.intersection(codePoints)`
Expand Down Expand Up @@ -295,7 +295,7 @@ regenerate(codePoints).toString();

## Support

Regenerate supports at least Chrome 27+, Firefox 3+, Safari 4+, Opera 10+, IE 6+, Node.js v0.10.0+, Narwhal 0.3.2+, RingoJS 0.8+, PhantomJS 1.9.0+, and Rhino 1.7RC4+.
Regenerate supports at least Chrome 27+, Firefox 3+, Safari 4+, Opera 10+, IE 6+, Node.js v0.10.0+, io.js v1.0.0+, Narwhal 0.3.2+, RingoJS 0.8+, PhantomJS 1.9.0+, and Rhino 1.7RC4+.

## Unit tests & code coverage

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148 changes: 104 additions & 44 deletions regenerate.js
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Original file line number Diff line number Diff line change
Expand Up @@ -626,6 +626,7 @@
var splitAtBMP = function(data) {
// Iterate over the data per `(start, end)` pair.
var loneHighSurrogates = [];
var loneLowSurrogates = [];
var bmp = [];
var astral = [];
var index = 0;
Expand All @@ -635,51 +636,105 @@
while (index < length) {
start = data[index];
end = data[index + 1] - 1; // Note: the `- 1` makes `end` inclusive.
if (start <= 0xFFFF && end <= 0xFFFF) {
// Both `start` and `end` are within the BMP range.
if (start >= HIGH_SURROGATE_MIN && start <= HIGH_SURROGATE_MAX) {
// `start` lies in the high surrogates range.
if (end <= HIGH_SURROGATE_MAX) {
loneHighSurrogates.push(start, end + 1);
} else {
loneHighSurrogates.push(start, HIGH_SURROGATE_MAX + 1);
bmp.push(HIGH_SURROGATE_MAX + 1, end + 1);
}
} else if (end >= HIGH_SURROGATE_MIN && end <= HIGH_SURROGATE_MAX) {

if (start < HIGH_SURROGATE_MIN) {

// starts before high surr & ends before high surr e.g. (0, 0x10)
if (end < HIGH_SURROGATE_MIN) {
bmp.push(start, end + 1);
}

// starts before high surr & ends in high surr range e.g. (0, 0xD855)
if (end >= HIGH_SURROGATE_MIN && end <= HIGH_SURROGATE_MAX) {
bmp.push(start, HIGH_SURROGATE_MIN);
loneHighSurrogates.push(HIGH_SURROGATE_MIN, end + 1);
} else if (start < HIGH_SURROGATE_MIN && end > HIGH_SURROGATE_MAX) {
bmp.push(start, HIGH_SURROGATE_MIN, HIGH_SURROGATE_MAX + 1, end + 1);
}

// starts before high surr & ends in low surr range e.g. (0, 0xDCFF)
if (end >= LOW_SURROGATE_MIN && end <= LOW_SURROGATE_MAX) {
bmp.push(start, HIGH_SURROGATE_MIN);
loneHighSurrogates.push(HIGH_SURROGATE_MIN, HIGH_SURROGATE_MAX + 1);
} else {
bmp.push(start, end + 1);
loneLowSurrogates.push(LOW_SURROGATE_MIN, end + 1);
}
}
else if (start <= 0xFFFF && end > 0xFFFF) {
// `start` is in the BMP range, but `end` lies within the astral range.
if (start >= HIGH_SURROGATE_MIN && start <= HIGH_SURROGATE_MAX) {
// `start` lies in the high surrogates range. Since `end` is astral,
// we can just add all high surrogates starting from `start` to
// `loneHighSurrogates`, any other BMP code points to `bmp`, and the
// remaining symbols to `astral`.
loneHighSurrogates.push(start, HIGH_SURROGATE_MAX + 1);
bmp.push(HIGH_SURROGATE_MAX + 1, 0xFFFF + 1);
} else if (start < HIGH_SURROGATE_MIN) {
bmp.push(start, HIGH_SURROGATE_MIN, HIGH_SURROGATE_MAX + 1, 0xFFFF + 1);

// starts before high surr & ends after low surr e.g. (0, 0x10FFFF)
if (end > LOW_SURROGATE_MAX) {
bmp.push(start, HIGH_SURROGATE_MIN);
loneHighSurrogates.push(HIGH_SURROGATE_MIN, HIGH_SURROGATE_MAX + 1);
} else { // `start > HIGH_SURROGATE_MAX` holds true.
loneLowSurrogates.push(LOW_SURROGATE_MIN, LOW_SURROGATE_MAX + 1);
if (end <= 0xFFFF) {
bmp.push(LOW_SURROGATE_MAX + 1, end + 1);
} else {
bmp.push(LOW_SURROGATE_MAX + 1, 0xFFFF + 1);
astral.push(0xFFFF + 1, end + 1);
}
}

} else if (start >= HIGH_SURROGATE_MIN && start <= HIGH_SURROGATE_MAX) {

// starts in high surr range & ends in high surr range e.g. (0xD855, 0xD866)
if (end >= HIGH_SURROGATE_MIN && end <= HIGH_SURROGATE_MAX) {
loneHighSurrogates.push(start, end + 1);
}

// starts in high surr range & ends in low surr range e.g. (0xD855, 0xDCFF)
if (end >= LOW_SURROGATE_MIN && end <= LOW_SURROGATE_MAX) {
loneHighSurrogates.push(start, HIGH_SURROGATE_MAX + 1);
loneLowSurrogates.push(LOW_SURROGATE_MIN, end + 1);
}

// starts in high surr range & ends after low surr e.g. (0xD855, 0x10FFFF)
if (end > LOW_SURROGATE_MAX) {
loneHighSurrogates.push(start, HIGH_SURROGATE_MAX + 1);
loneLowSurrogates.push(LOW_SURROGATE_MIN, LOW_SURROGATE_MAX + 1);
if (end <= 0xFFFF) {
bmp.push(LOW_SURROGATE_MAX + 1, end + 1);
} else {
bmp.push(LOW_SURROGATE_MAX + 1, 0xFFFF + 1);
astral.push(0xFFFF + 1, end + 1);
}
}

} else if (start >= LOW_SURROGATE_MIN && start <= LOW_SURROGATE_MAX) {

// starts in low surr range & ends in low surr range e.g. (0xDCFF, 0xDDFF)
if (end >= LOW_SURROGATE_MIN && end <= LOW_SURROGATE_MAX) {
loneLowSurrogates.push(start, end + 1);
}

// starts in low surr range & ends after low surr in BMP e.g. (0xDCFF, 0xFFFF)
if (end > LOW_SURROGATE_MAX) {
loneLowSurrogates.push(start, LOW_SURROGATE_MAX + 1);
if (end <= 0xFFFF) {
bmp.push(LOW_SURROGATE_MAX + 1, end + 1);
} else {
bmp.push(LOW_SURROGATE_MAX + 1, 0xFFFF + 1);
astral.push(0xFFFF + 1, end + 1);
}
}

} else if (start > LOW_SURROGATE_MAX && start <= 0xFFFF) {

// starts after low surr in BMP & ends after low surr e.g. (0xFFAA, 0x10FFFF)
if (end <= 0xFFFF) {
bmp.push(start, end + 1);
} else {
bmp.push(start, 0xFFFF + 1);
astral.push(0xFFFF + 1, end + 1);
}
astral.push(0xFFFF + 1, end + 1);
}
else {

} else {

// Both `start` and `end` are in the astral range.
astral.push(start, end + 1);

}

index += 2;
}
return {
'loneHighSurrogates': loneHighSurrogates,
'loneLowSurrogates': loneLowSurrogates,
'bmp': bmp,
'astral': astral
};
Expand Down Expand Up @@ -898,19 +953,15 @@

var parts = splitAtBMP(data);
var loneHighSurrogates = parts.loneHighSurrogates;
var loneLowSurrogates = parts.loneLowSurrogates;
var bmp = parts.bmp;
var astral = parts.astral;
var hasAstral = !dataIsEmpty(parts.astral);
var hasLoneSurrogates = !dataIsEmpty(loneHighSurrogates);
var hasLoneHighSurrogates = !dataIsEmpty(loneHighSurrogates);
var hasLoneLowSurrogates = !dataIsEmpty(loneLowSurrogates);

var surrogateMappings = surrogateSet(astral);

// If we’re not dealing with any astral symbols, there’s no need to move
// individual code points that are high surrogates to the end of the regex.
if (!hasAstral && hasLoneSurrogates) {
bmp = dataAddData(bmp, loneHighSurrogates);
}

if (!dataIsEmpty(bmp)) {
// The data set contains BMP code points that are not high surrogates
// needed for astral code points in the set.
Expand All @@ -921,11 +972,20 @@
// based on their surrogate pairs.
result.push(createSurrogateCharacterClasses(surrogateMappings));
}
if (hasAstral && hasLoneSurrogates) {
// The data set contains lone high surrogates; append these. Lone high
// surrogates must go at the end of the regex if astral symbols are to be
// matched as well.
result.push(createBMPCharacterClasses(loneHighSurrogates));
// https://gist.github.com/mathiasbynens/bbe7f870208abcfec860
if (hasLoneHighSurrogates) {
result.push(
createBMPCharacterClasses(loneHighSurrogates) +
// Make sure the high surrogates aren’t part of a surrogate pair.
'(?![\\uDC00-\\uDFFF])'
);
}
if (hasLoneLowSurrogates) {
result.push(
// Make sure the low surrogates aren’t part of a surrogate pair.
'(?:[^\\uD800-\\uDBFF]|^)' +
createBMPCharacterClasses(loneLowSurrogates)
);
}
return result.join('|');
};
Expand Down Expand Up @@ -1066,7 +1126,7 @@
return regenerate;
});
} else if (freeExports && !freeExports.nodeType) {
if (freeModule) { // in Node.js or RingoJS v0.8.0+
if (freeModule) { // in Node.js, io.js, or RingoJS v0.8.0+
freeModule.exports = regenerate;
} else { // in Narwhal or RingoJS v0.7.0-
freeExports.regenerate = regenerate;
Expand Down
29 changes: 18 additions & 11 deletions tests/tests.js
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