125 lines
3.4 KiB
JavaScript
125 lines
3.4 KiB
JavaScript
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++;
|
|
};
|