Lexer

Return true if next char is white space. Does not advance. Note that browsers are inconsistent in their definitions of the \s metacharacter, so use an explicit string match instead.

• Chrome: [ \t\n\v\f\r\u00A0]
• Firefox: [ \t\n\v\f\r\u00A0\u2028\u2029]
• IE: [ \t\n\v\f\r]

See Stackoverflow

Return a single token, or null, created from the lexer.

Return the next char, but do not advance

Return the next substring matching regEx and advance.