Lexer constructor
Lexer()
Creates a new lexer.
Implementation
Lexer() {
keywords['+'] = TokenType.PLUS;
keywords['-'] = TokenType.MINUS;
keywords['*'] = TokenType.TIMES;
keywords['/'] = TokenType.DIV;
keywords['%'] = TokenType.MOD;
keywords['^'] = TokenType.POW;
keywords['!'] = TokenType.FACTORIAL;
keywords['nrt'] = TokenType.ROOT;
keywords['sqrt'] = TokenType.SQRT;
keywords['log'] = TokenType.LOG;
keywords['cos'] = TokenType.COS;
keywords['sin'] = TokenType.SIN;
keywords['tan'] = TokenType.TAN;
keywords['arccos'] = TokenType.ACOS;
keywords['arcsin'] = TokenType.ASIN;
keywords['arctan'] = TokenType.ATAN;
keywords['abs'] = TokenType.ABS;
keywords['ceil'] = TokenType.CEIL;
keywords['floor'] = TokenType.FLOOR;
keywords['sgn'] = TokenType.SGN;
keywords['ln'] = TokenType.LN;
keywords['e'] = TokenType.EFUNC;
keywords['('] = TokenType.LBRACE;
keywords[')'] = TokenType.RBRACE;
keywords['{'] = TokenType.LBRACE;
keywords['}'] = TokenType.RBRACE;
keywords[','] = TokenType.SEPAR;
}