CasperSecurity
var EOF = 0;
// https://drafts.csswg.org/css-syntax-3/
// § 4.2. Definitions
// digit
// A code point between U+0030 DIGIT ZERO (0) and U+0039 DIGIT NINE (9).
function isDigit(code) {
return code >= 0x0030 && code <= 0x0039;
}
// hex digit
// A digit, or a code point between U+0041 LATIN CAPITAL LETTER A (A) and U+0046 LATIN CAPITAL LETTER F (F),
// or a code point between U+0061 LATIN SMALL LETTER A (a) and U+0066 LATIN SMALL LETTER F (f).
function isHexDigit(code) {
return (
isDigit(code) || // 0 .. 9
(code >= 0x0041 && code <= 0x0046) || // A .. F
(code >= 0x0061 && code <= 0x0066) // a .. f
);
}
// uppercase letter
// A code point between U+0041 LATIN CAPITAL LETTER A (A) and U+005A LATIN CAPITAL LETTER Z (Z).
function isUppercaseLetter(code) {
return code >= 0x0041 && code <= 0x005A;
}
// lowercase letter
// A code point between U+0061 LATIN SMALL LETTER A (a) and U+007A LATIN SMALL LETTER Z (z).
function isLowercaseLetter(code) {
return code >= 0x0061 && code <= 0x007A;
}
// letter
// An uppercase letter or a lowercase letter.
function isLetter(code) {
return isUppercaseLetter(code) || isLowercaseLetter(code);
}
// non-ASCII code point
// A code point with a value equal to or greater than U+0080 <control>.
function isNonAscii(code) {
return code >= 0x0080;
}
// name-start code point
// A letter, a non-ASCII code point, or U+005F LOW LINE (_).
function isNameStart(code) {
return isLetter(code) || isNonAscii(code) || code === 0x005F;
}
// name code point
// A name-start code point, a digit, or U+002D HYPHEN-MINUS (-).
function isName(code) {
return isNameStart(code) || isDigit(code) || code === 0x002D;
}
// non-printable code point
// A code point between U+0000 NULL and U+0008 BACKSPACE, or U+000B LINE TABULATION,
// or a code point between U+000E SHIFT OUT and U+001F INFORMATION SEPARATOR ONE, or U+007F DELETE.
function isNonPrintable(code) {
return (
(code >= 0x0000 && code <= 0x0008) ||
(code === 0x000B) ||
(code >= 0x000E && code <= 0x001F) ||
(code === 0x007F)
);
}
// newline
// U+000A LINE FEED. Note that U+000D CARRIAGE RETURN and U+000C FORM FEED are not included in this definition,
// as they are converted to U+000A LINE FEED during preprocessing.
// TODO: we doesn't do a preprocessing, so check a code point for U+000D CARRIAGE RETURN and U+000C FORM FEED
function isNewline(code) {
return code === 0x000A || code === 0x000D || code === 0x000C;
}
// whitespace
// A newline, U+0009 CHARACTER TABULATION, or U+0020 SPACE.
function isWhiteSpace(code) {
return isNewline(code) || code === 0x0020 || code === 0x0009;
}
// § 4.3.8. Check if two code points are a valid escape
function isValidEscape(first, second) {
// If the first code point is not U+005C REVERSE SOLIDUS (\), return false.
if (first !== 0x005C) {
return false;
}
// Otherwise, if the second code point is a newline or EOF, return false.
if (isNewline(second) || second === EOF) {
return false;
}
// Otherwise, return true.
return true;
}
// § 4.3.9. Check if three code points would start an identifier
function isIdentifierStart(first, second, third) {
// Look at the first code point:
// U+002D HYPHEN-MINUS
if (first === 0x002D) {
// If the second code point is a name-start code point or a U+002D HYPHEN-MINUS,
// or the second and third code points are a valid escape, return true. Otherwise, return false.
return (
isNameStart(second) ||
second === 0x002D ||
isValidEscape(second, third)
);
}
// name-start code point
if (isNameStart(first)) {
// Return true.
return true;
}
// U+005C REVERSE SOLIDUS (\)
if (first === 0x005C) {
// If the first and second code points are a valid escape, return true. Otherwise, return false.
return isValidEscape(first, second);
}
// anything else
// Return false.
return false;
}
// § 4.3.10. Check if three code points would start a number
function isNumberStart(first, second, third) {
// Look at the first code point:
// U+002B PLUS SIGN (+)
// U+002D HYPHEN-MINUS (-)
if (first === 0x002B || first === 0x002D) {
// If the second code point is a digit, return true.
if (isDigit(second)) {
return 2;
}
// Otherwise, if the second code point is a U+002E FULL STOP (.)
// and the third code point is a digit, return true.
// Otherwise, return false.
return second === 0x002E && isDigit(third) ? 3 : 0;
}
// U+002E FULL STOP (.)
if (first === 0x002E) {
// If the second code point is a digit, return true. Otherwise, return false.
return isDigit(second) ? 2 : 0;
}
// digit
if (isDigit(first)) {
// Return true.
return 1;
}
// anything else
// Return false.
return 0;
}
//
// Misc
//
// detect BOM (https://en.wikipedia.org/wiki/Byte_order_mark)
function isBOM(code) {
// UTF-16BE
if (code === 0xFEFF) {
return 1;
}
// UTF-16LE
if (code === 0xFFFE) {
return 1;
}
return 0;
}
// Fast code category
//
// https://drafts.csswg.org/css-syntax/#tokenizer-definitions
// > non-ASCII code point
// > A code point with a value equal to or greater than U+0080 <control>
// > name-start code point
// > A letter, a non-ASCII code point, or U+005F LOW LINE (_).
// > name code point
// > A name-start code point, a digit, or U+002D HYPHEN-MINUS (-)
// That means only ASCII code points has a special meaning and we define a maps for 0..127 codes only
var CATEGORY = new Array(0x80);
charCodeCategory.Eof = 0x80;
charCodeCategory.WhiteSpace = 0x82;
charCodeCategory.Digit = 0x83;
charCodeCategory.NameStart = 0x84;
charCodeCategory.NonPrintable = 0x85;
for (var i = 0; i < CATEGORY.length; i++) {
switch (true) {
case isWhiteSpace(i):
CATEGORY[i] = charCodeCategory.WhiteSpace;
break;
case isDigit(i):
CATEGORY[i] = charCodeCategory.Digit;
break;
case isNameStart(i):
CATEGORY[i] = charCodeCategory.NameStart;
break;
case isNonPrintable(i):
CATEGORY[i] = charCodeCategory.NonPrintable;
break;
default:
CATEGORY[i] = i || charCodeCategory.Eof;
}
}
function charCodeCategory(code) {
return code < 0x80 ? CATEGORY[code] : charCodeCategory.NameStart;
};
module.exports = {
isDigit: isDigit,
isHexDigit: isHexDigit,
isUppercaseLetter: isUppercaseLetter,
isLowercaseLetter: isLowercaseLetter,
isLetter: isLetter,
isNonAscii: isNonAscii,
isNameStart: isNameStart,
isName: isName,
isNonPrintable: isNonPrintable,
isNewline: isNewline,
isWhiteSpace: isWhiteSpace,
isValidEscape: isValidEscape,
isIdentifierStart: isIdentifierStart,
isNumberStart: isNumberStart,
isBOM: isBOM,
charCodeCategory: charCodeCategory
};