'first'

fcs

2025-04-10 0163870d662dc5b7d69ceff977490ede594f7d82

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'use strict';
 
var assert = require('assert');
var TokenStream = require('../');
 
assert.throws(function () {
  new TokenStream('foo,bar');
});
var stream = new TokenStream([
  'a',
  'b',
  'c',
  'd'
]);
assert.throws(function () {
  stream.lookahead(9);
});
assert(stream.peek() === 'a');
assert(stream.lookahead(0) == 'a');
assert(stream.lookahead(1) == 'b');
 
assert(stream.advance() === 'a');
assert(stream.peek() === 'b');
assert(stream.lookahead(0) == 'b');
assert(stream.lookahead(1) == 'c');
 
stream.defer('z');
assert(stream.peek() === 'z');
assert(stream.lookahead(0) == 'z');
assert(stream.lookahead(1) == 'b');
assert(stream.advance() === 'z');
assert(stream.advance() === 'b');
assert(stream.advance() === 'c');
assert(stream.advance() === 'd');
assert.throws(function () {
  stream.peek();
});
assert.throws(function () {
  stream.lookahead(0);
});
assert.throws(function () {
  stream.lookahead(1);
});
assert.throws(function () {
  stream.advance();
});