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build/node_modules/css-tree/lib/tokenizer/utils.js

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+'use strict';
+
+var constants = require('./const');
+var PUNCTUATION = constants.PUNCTUATION;
+var STOP_URL_RAW = constants.STOP_URL_RAW;
+var TYPE = constants.TYPE;
+var FULLSTOP = TYPE.FullStop;
+var PLUSSIGN = TYPE.PlusSign;
+var HYPHENMINUS = TYPE.HyphenMinus;
+var PUNCTUATOR = TYPE.Punctuator;
+var TAB = 9;
+var N = 10;
+var F = 12;
+var R = 13;
+var SPACE = 32;
+var BACK_SLASH = 92;
+var E = 101; // 'e'.charCodeAt(0)
+
+function firstCharOffset(source) {
+    // detect BOM (https://en.wikipedia.org/wiki/Byte_order_mark)
+    if (source.charCodeAt(0) === 0xFEFF ||  // UTF-16BE
+        source.charCodeAt(0) === 0xFFFE) {  // UTF-16LE
+        return 1;
+    }
+
+    return 0;
+}
+
+function isHex(code) {
+    return (code >= 48 && code <= 57) || // 0 .. 9
+           (code >= 65 && code <= 70) || // A .. F
+           (code >= 97 && code <= 102);  // a .. f
+}
+
+function isNumber(code) {
+    return code >= 48 && code <= 57;
+}
+
+function isNewline(source, offset, code) {
+    if (code === N || code === F || code === R) {
+        if (code === R && offset + 1 < source.length && source.charCodeAt(offset + 1) === N) {
+            return 2;
+        }
+
+        return 1;
+    }
+
+    return 0;
+}
+
+function cmpChar(testStr, offset, referenceCode) {
+    var code = testStr.charCodeAt(offset);
+
+    // code.toLowerCase()
+    if (code >= 65 && code <= 90) {
+        code = code | 32;
+    }
+
+    return code === referenceCode;
+}
+
+function cmpStr(testStr, start, end, referenceStr) {
+    if (end - start !== referenceStr.length) {
+        return false;
+    }
+
+    if (start < 0 || end > testStr.length) {
+        return false;
+    }
+
+    for (var i = start; i < end; i++) {
+        var testCode = testStr.charCodeAt(i);
+        var refCode = referenceStr.charCodeAt(i - start);
+
+        // testStr[i].toLowerCase()
+        if (testCode >= 65 && testCode <= 90) {
+            testCode = testCode | 32;
+        }
+
+        if (testCode !== refCode) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+function endsWith(testStr, referenceStr) {
+    return cmpStr(testStr, testStr.length - referenceStr.length, testStr.length, referenceStr);
+}
+
+function findLastNonSpaceLocation(scanner) {
+    for (var i = scanner.source.length - 1; i >= 0; i--) {
+        var code = scanner.source.charCodeAt(i);
+
+        if (code !== SPACE && code !== TAB && code !== R && code !== N && code !== F) {
+            break;
+        }
+    }
+
+    return scanner.getLocation(i + 1);
+}
+
+function findWhiteSpaceEnd(source, offset) {
+    for (; offset < source.length; offset++) {
+        var code = source.charCodeAt(offset);
+
+        if (code !== SPACE && code !== TAB && code !== R && code !== N && code !== F) {
+            break;
+        }
+    }
+
+    return offset;
+}
+
+function findCommentEnd(source, offset) {
+    var commentEnd = source.indexOf('*/', offset);
+
+    if (commentEnd === -1) {
+        return source.length;
+    }
+
+    return commentEnd + 2;
+}
+
+function findStringEnd(source, offset, quote) {
+    for (; offset < source.length; offset++) {
+        var code = source.charCodeAt(offset);
+
+        // TODO: bad string
+        if (code === BACK_SLASH) {
+            offset++;
+        } else if (code === quote) {
+            offset++;
+            break;
+        }
+    }
+
+    return offset;
+}
+
+function findDecimalNumberEnd(source, offset) {
+    for (; offset < source.length; offset++) {
+        var code = source.charCodeAt(offset);
+
+        if (code < 48 || code > 57) {  // not a 0 .. 9
+            break;
+        }
+    }
+
+    return offset;
+}
+
+function findNumberEnd(source, offset, allowFraction) {
+    var code;
+
+    offset = findDecimalNumberEnd(source, offset);
+
+    // fraction: .\d+
+    if (allowFraction && offset + 1 < source.length && source.charCodeAt(offset) === FULLSTOP) {
+        code = source.charCodeAt(offset + 1);
+
+        if (isNumber(code)) {
+            offset = findDecimalNumberEnd(source, offset + 1);
+        }
+    }
+
+    // exponent: e[+-]\d+
+    if (offset + 1 < source.length) {
+        if ((source.charCodeAt(offset) | 32) === E) { // case insensitive check for `e`
+            code = source.charCodeAt(offset + 1);
+
+            if (code === PLUSSIGN || code === HYPHENMINUS) {
+                if (offset + 2 < source.length) {
+                    code = source.charCodeAt(offset + 2);
+                }
+            }
+
+            if (isNumber(code)) {
+                offset = findDecimalNumberEnd(source, offset + 2);
+            }
+        }
+    }
+
+    return offset;
+}
+
+// skip escaped unicode sequence that can ends with space
+// [0-9a-f]{1,6}(\r\n|[ \n\r\t\f])?
+function findEscaseEnd(source, offset) {
+    for (var i = 0; i < 7 && offset + i < source.length; i++) {
+        var code = source.charCodeAt(offset + i);
+
+        if (i !== 6 && isHex(code)) {
+            continue;
+        }
+
+        if (i > 0) {
+            offset += i - 1 + isNewline(source, offset + i, code);
+            if (code === SPACE || code === TAB) {
+                offset++;
+            }
+        }
+
+        break;
+    }
+
+    return offset;
+}
+
+function findIdentifierEnd(source, offset) {
+    for (; offset < source.length; offset++) {
+        var code = source.charCodeAt(offset);
+
+        if (code === BACK_SLASH) {
+            offset = findEscaseEnd(source, offset + 1);
+        } else if (code < 0x80 && PUNCTUATION[code] === PUNCTUATOR) {
+            break;
+        }
+    }
+
+    return offset;
+}
+
+function findUrlRawEnd(source, offset) {
+    for (; offset < source.length; offset++) {
+        var code = source.charCodeAt(offset);
+
+        if (code === BACK_SLASH) {
+            offset = findEscaseEnd(source, offset + 1);
+        } else if (code < 0x80 && STOP_URL_RAW[code] === 1) {
+            break;
+        }
+    }
+
+    return offset;
+}
+
+module.exports = {
+    firstCharOffset: firstCharOffset,
+
+    isHex: isHex,
+    isNumber: isNumber,
+    isNewline: isNewline,
+
+    cmpChar: cmpChar,
+    cmpStr: cmpStr,
+    endsWith: endsWith,
+
+    findLastNonSpaceLocation: findLastNonSpaceLocation,
+    findWhiteSpaceEnd: findWhiteSpaceEnd,
+    findCommentEnd: findCommentEnd,
+    findStringEnd: findStringEnd,
+    findDecimalNumberEnd: findDecimalNumberEnd,
+    findNumberEnd: findNumberEnd,
+    findEscaseEnd: findEscaseEnd,
+    findIdentifierEnd: findIdentifierEnd,
+    findUrlRawEnd: findUrlRawEnd
+};