200   | 
   200   | 
   201 // Language specific code  | 
   201 // Language specific code  | 
   202 val KEYWORD : Rexp = "while" | "if" | "then" | "else" | "do" | "for" | "to" | "true" | "false" | "read" | "write" | "skip"   | 
   202 val KEYWORD : Rexp = "while" | "if" | "then" | "else" | "do" | "for" | "to" | "true" | "false" | "read" | "write" | "skip"   | 
   203 val OP : Rexp = "+" | "-" | "*" | "%" | "/" | "==" | "!=" | ">" | "<" | ">=" | "<=" | ":=" | "&&" | "||"  | 
   203 val OP : Rexp = "+" | "-" | "*" | "%" | "/" | "==" | "!=" | ">" | "<" | ">=" | "<=" | ":=" | "&&" | "||"  | 
   204 val LET: Rexp = RANGE(('A' to 'Z').toSet ++ ('a' to 'z')) | 
   204 val LET: Rexp = RANGE(('A' to 'Z').toSet ++ ('a' to 'z')) | 
   205 val SYM : Rexp = LET | RANGE(Set('.', '_', '>', '<', '=', ';', ',', ':')) | 
   205 val SYM : Rexp = (LET | RANGE(Set('.', '_', '>', '<', '=', ';', ',', ':'))) | 
   206 val PARENS : Rexp = "(" | "{" | ")" | "}" | 
   206 val PARENS : Rexp = "(" | "{" | ")" | "}" | 
   207 val SEMI : Rexp = ";"  | 
   207 val SEMI : Rexp = ";"  | 
   208 val WHITESPACE : Rexp = PLUS(" ") | "\n" | "\t" | 
   208 val WHITESPACE : Rexp = PLUS(" ") | "\n" | "\t" | "\r" | 
   209 val DIGIT : Rexp = RANGE(('0' to '9').toSet) | 
   209 val DIGIT : Rexp = RANGE(('0' to '9').toSet) | 
   210 val DIGIT1 : Rexp = RANGE(('1' to '9').toSet) | 
   210 val DIGIT1 : Rexp = RANGE(('1' to '9').toSet) | 
   211 val STRING : Rexp = "\"" ~ (SYM | " " | "\\n" | DIGIT).% ~ "\""  | 
   211 val STRING : Rexp = "\"" ~ (SYM | " " | "\\n" | DIGIT).% ~ "\""  | 
   212 val ID : Rexp = LET ~ (LET | "_" | DIGIT).%  | 
   212 val ID : Rexp = LET ~ (LET | "_" | DIGIT).%  | 
   213 val NUM : Rexp = "0" | (DIGIT1 ~ DIGIT.%)  | 
   213 val NUM : Rexp = "0" | (DIGIT1 ~ DIGIT.%)  | 
   214 val COMMENT : Rexp = "//" ~ (SYM | " " | DIGIT).% ~ "\n"   | 
   214 val EOL : Rexp = "\n" | "\r\n"  | 
         | 
   215 val COMMENT : Rexp = "//" ~ (SYM | PARENS | " " | DIGIT).% ~ EOL   | 
   215   | 
   216   | 
   216 val WHILE_REGS = (("k" $ KEYWORD) |  | 
   217 val WHILE_REGS = (("k" $ KEYWORD) |  | 
   217                   ("o" $ OP) |  | 
   218                   ("o" $ OP) |  | 
   218                   ("str" $ STRING) | | 
   219                   ("str" $ STRING) | | 
   219                   ("p" $ PARENS) | | 
   220                   ("p" $ PARENS) | |