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qwen/nodejs/node_modules/wkx/lib/wktparser.js

@@ -0,0 +1,124 @@
+module.exports = WktParser;
+
+var Types = require('./types');
+var Point = require('./point');
+
+function WktParser(value) {
+    this.value = value;
+    this.position = 0;
+}
+
+WktParser.prototype.match = function (tokens) {
+    this.skipWhitespaces();
+
+    for (var i = 0; i < tokens.length; i++) {
+        if (this.value.substring(this.position).indexOf(tokens[i]) === 0) {
+            this.position += tokens[i].length;
+            return tokens[i];
+        }
+    }
+
+    return null;
+};
+
+WktParser.prototype.matchRegex = function (tokens) {
+    this.skipWhitespaces();
+
+    for (var i = 0; i < tokens.length; i++) {
+        var match = this.value.substring(this.position).match(tokens[i]);
+
+        if (match) {
+            this.position += match[0].length;
+            return match;
+        }
+    }
+
+    return null;
+};
+
+WktParser.prototype.isMatch = function (tokens) {
+    this.skipWhitespaces();
+
+    for (var i = 0; i < tokens.length; i++) {
+        if (this.value.substring(this.position).indexOf(tokens[i]) === 0) {
+            this.position += tokens[i].length;
+            return true;
+        }
+    }
+
+    return false;
+};
+
+WktParser.prototype.matchType = function () {
+    var geometryType = this.match([Types.wkt.Point, Types.wkt.LineString, Types.wkt.Polygon, Types.wkt.MultiPoint,
+    Types.wkt.MultiLineString, Types.wkt.MultiPolygon, Types.wkt.GeometryCollection]);
+
+    if (!geometryType)
+        throw new Error('Expected geometry type');
+
+    return geometryType;
+};
+
+WktParser.prototype.matchDimension = function () {
+    var dimension = this.match(['ZM', 'Z', 'M']);
+
+    switch (dimension) {
+        case 'ZM': return { hasZ: true, hasM: true };
+        case 'Z': return { hasZ: true, hasM: false };
+        case 'M': return { hasZ: false, hasM: true };
+        default: return { hasZ: false, hasM: false };
+    }
+};
+
+WktParser.prototype.expectGroupStart = function () {
+    if (!this.isMatch(['(']))
+        throw new Error('Expected group start');
+};
+
+WktParser.prototype.expectGroupEnd = function () {
+    if (!this.isMatch([')']))
+        throw new Error('Expected group end');
+};
+
+WktParser.prototype.matchCoordinate = function (options) {
+    var match;
+
+    if (options.hasZ && options.hasM)
+        match = this.matchRegex([/^(\S*)\s+(\S*)\s+(\S*)\s+([^\s,)]*)/]);
+    else if (options.hasZ || options.hasM)
+        match = this.matchRegex([/^(\S*)\s+(\S*)\s+([^\s,)]*)/]);
+    else
+        match = this.matchRegex([/^(\S*)\s+([^\s,)]*)/]);
+
+    if (!match)
+        throw new Error('Expected coordinates');
+
+    if (options.hasZ && options.hasM)
+        return new Point(parseFloat(match[1]), parseFloat(match[2]), parseFloat(match[3]), parseFloat(match[4]));
+    else if (options.hasZ)
+        return new Point(parseFloat(match[1]), parseFloat(match[2]), parseFloat(match[3]));
+    else if (options.hasM)
+        return new Point(parseFloat(match[1]), parseFloat(match[2]), undefined, parseFloat(match[3]));
+    else
+        return new Point(parseFloat(match[1]), parseFloat(match[2]));
+};
+
+WktParser.prototype.matchCoordinates = function (options) {
+    var coordinates = [];
+
+    do {
+        var startsWithBracket = this.isMatch(['(']);
+
+        coordinates.push(this.matchCoordinate(options));
+
+        if (startsWithBracket)
+            this.expectGroupEnd();
+    } while (this.isMatch([',']));
+
+    return coordinates;
+};
+
+WktParser.prototype.skipWhitespaces = function () {
+    while (this.position < this.value.length && this.value[this.position] === ' ')
+        this.position++;
+};