LOG3210 - TP1

tp1.scala

import scala.util.parsing.combinator._

object Main
{
	def main(args: Array[String]) 
	{
		println(TP1.parseAll(TP1.program, args(0)))
	}
}

object TP1 extends JavaTokenParsers
{
	def program: Parser[Any] = block
	def block: Parser[Any] = rep( statement )
	def statement: Parser[Any] = (
			assignementStatement ~ ";"
		|	inputOutputStatement ~ ";"
		|	ifStatement
		|	whileStatement
	)
	def assignementStatement: Parser[Any] = 
	{
		ident ~ {
			"=" |
			"+=" |
			"-=" |
			"*=" |
			"/=" |
			"^="
		} ~ expression
	} 

	def inputOutputStatement: Parser[Any] = {
	  "print" ~ "(" ~ expression ~ ")" |
	  "input"
	}
	def ifStatement: Parser[Any] = 
	{
		"if" ~ "(" ~ expression ~ ")" ~ "{" ~ block ~ "}" ~ "else" ~ "{" ~ block ~ "}" |
		"if" ~ "(" ~ expression ~ ")" ~ "{" ~ block ~ "}"
	}
	def whileStatement: Parser[Any] =
	{
		"while" ~ "(" ~ expression ~ ")" ~ "{" ~ block ~ "}"
	}
	
	def expression: Parser[Any] = addExpression
	
	def addExpression: Parser[Any] = 
	{
		multiplicationExpression ~
		rep( ( "+" | "-" ) ~ multiplicationExpression )
	}
	
	def multiplicationExpression: Parser[Any] = 
	{
		powerExpression ~
		rep( ( "*" | "/" ) ~ powerExpression )
	}
	
	def powerExpression: Parser[Any] = 
	{
		factorialExpression ~
		rep( "^" ~ factorialExpression )
	}
	
	def factorialExpression: Parser[Any] = 
	{
		unaryExpression ~ opt( "!" )
	}
	
	def unaryExpression: Parser[Any] = 
	{
		rep( "-" ) ~ basicExpression
	}
	
	def basicExpression: Parser[Any] = 
	{
		ident |
		wholeNumber |
		decimalNumber |
		floatingPointNumber |
		"(" ~ expression ~ ")"
	}
}