%{
/****************************************************************************
parser.y
ParserWizard generated YACC file.

Date: 07 December 2000
****************************************************************************/

#include "function.h"
#include "lexer.h"
#include "codegen.h"


%}

/////////////////////////////////////////////////////////////////////////////
// declarations section

// parser name
%name myparser

// class definition
{
public:
	void	setCurrentLexer(class mylexer *_lexer);
	void	setBaseNode(class CTreeNode *_baseNode);

	// Overridden parser functions
	void	yyerror(const char *_text);
	int		yyparse();

private:
	class mylexer	*m_currentLexer;
	class CTreeNode	*m_baseNode;

	// Ugh! (pkg)
	class CTreeNode	*m_functionArgs;
	int				m_functionNumber;

}

// constructor
{
	// place any extra initialisation code here
}

//// attribute type
//%include {
//#ifndef YYSTYPE
//#define YYSTYPE int
//#endif
//}

%union {
	int					variableIdx;
	signed short		value;
	int					functionNumber;
	class CTreeNode		*treenode;
}



// place any declarations here


%token	STOP
%token	IF
%token	ELSE
%token	WHILE
%token	DO
%token	PAUSE
%token	PRINT
%token	ASSIGN
%token	EQUAL
%token	NOTEQUAL
%token	LESSTHAN
%token	GREATERTHAN
%token	PLUS
%token	SUBTRACT
%token	MULTIPLY
%token	DIVIDE
%token	END_STMT
%token	OPEN_PAR
%token	CLOSE_PAR
%token	BEGIN_CS
%token	END_CS
%token	COMMA
%token	<variableIdx>		VARIABLE
%token	<value>				VALUE
%token	<functionNumber>	FUNCTION


%type	<treenode>		program statement_list statement
%type	<treenode>		assign_expression
%type	<treenode>		conditional
%type	<treenode>		variable
%type	<treenode>		expression
%type	<treenode>		function

%%


/////////////////////////////////////////////////////////////////////////////
// rules section

// place your YACC rules here (there must be at least one)

program
	:statement_list												{s_baseTreeNode=$1;}
	;													

statement_list											
	:statement_list statement									{$$=new CTreeNode(STMT_LIST,$1,$2);}
	|															{$$=new CTreeNode(EMPTY_STMT);}
	;

statement
	:END_STMT													{$$=new CTreeNode(EMPTY_STMT);}
	|STOP END_STMT												{$$=new CTreeNode(STOP_STMT);}
	|PAUSE END_STMT												{$$=new CTreeNode(PAUSE_STMT);}
	|PRINT OPEN_PAR expression CLOSE_PAR END_STMT				{$$=new CTreeNode(PRINT_STMT,$3);}
	|assign_expression END_STMT									{$$=$1;}
	|IF OPEN_PAR conditional CLOSE_PAR statement				{$$=new CTreeNode(IF_STMT,$3,$5);}
	|IF OPEN_PAR conditional CLOSE_PAR statement ELSE statement	{$$=new CTreeNode(IFELSE_STMT,$3,$5,$7);}
	|WHILE OPEN_PAR conditional CLOSE_PAR statement				{$$=new CTreeNode(WHILE_STMT,$3,$5);}
	|DO statement WHILE OPEN_PAR conditional CLOSE_PAR END_STMT	{$$=new CTreeNode(DOWHILE_STMT,$2,$5);}
	|BEGIN_CS statement_list END_CS								{$$=new CTreeNode(STMT_LIST,$2);}
	|function END_STMT											{$$=new CTreeNode(STMT_LIST,$1,new CTreeNode(POP_STMT));}
	;


assign_expression
	:variable ASSIGN expression									{$$=new CTreeNode(ASSIGN_EXPR,$1,$3);}
	;													
														
														
conditional												
	:expression EQUAL expression								{$$=new CTreeNode(EQUAL_EXPR,$1,$3);}
	|expression NOTEQUAL expression								{$$=new CTreeNode(NOTEQUAL_EXPR,$1,$3);}
	|expression LESSTHAN expression								{$$=new CTreeNode(LESSTHAN_EXPR,$1,$3);}
	|expression GREATERTHAN expression							{$$=new CTreeNode(GREATERTHAN_EXPR,$1,$3);}
	;													
														
														
variable												
	:VARIABLE													{$$=new CTreeNode(VARIABLE_EXPR,$1);}		// variable id
	;													
														
expression													
	:VALUE														{$$=new CTreeNode(VALUE_EXPR,$1);}
	|OPEN_PAR expression CLOSE_PAR								{$$=$2;}
	|VARIABLE													{$$=new CTreeNode(VARIABLE_EXPR,$1);}		// variable value
//	|PLUS expression											{$$=$2;}
//	|SUBTRACT expression										{$$=new CTreeNode(STMT_LIST,CTreeNodeCTreeNode(VALUE_EXPR,$2);}
	|expression PLUS expression									{$$=new CTreeNode(PLUS_EXPR,$1,$3);}
	|expression SUBTRACT expression								{$$=new CTreeNode(SUBTRACT_EXPR,$1,$3);}
	|expression MULTIPLY expression								{$$=new CTreeNode(MULTIPLY_EXPR,$1,$3);}
	|expression DIVIDE expression								{$$=new CTreeNode(DIVIDE_EXPR,$1,$3);}
	|function													{$$=$1;}
	;													


function
	:FUNCTION OPEN_PAR											{if($1!=-1){m_functionNumber=$1;m_functionArgs=getFunctionArgs($1);}}
	 CLOSE_PAR													{$$=new CTreeNode(STMT_LIST,m_functionArgs,new CTreeNode(FUNCTION_EXPR,m_functionNumber));}
	;



%%


/////////////////////////////////////////////////////////////////////////////
// programs section