29 lines
849 B
JavaScript
29 lines
849 B
JavaScript
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var TokenIterator = module.exports = function(tokens, startIndex) {
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this._tokens = tokens;
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this._startIndex = startIndex || 0;
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};
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TokenIterator.prototype.head = function() {
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return this._tokens[this._startIndex];
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};
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TokenIterator.prototype.tail = function(startIndex) {
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return new TokenIterator(this._tokens, this._startIndex + 1);
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};
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TokenIterator.prototype.toArray = function() {
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return this._tokens.slice(this._startIndex);
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};
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TokenIterator.prototype.end = function() {
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return this._tokens[this._tokens.length - 1];
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};
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// TODO: doesn't need to be a method, can be a separate function,
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// which simplifies implementation of the TokenIterator interface
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TokenIterator.prototype.to = function(end) {
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var start = this.head().source;
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var endToken = end.head() || end.end();
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return start.to(endToken.source);
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};
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