Грамматика языка Pascal

--Венцко Александр Зиновьевич 21:11, 21 сентября 2011 (UTC)

Грамматика

%{
    Dictionary<string,double> vars = new Dictionary<string,double>();
%}

%output=Yacc.cs 

%union { 
	 public int iVal; 
	 public double dVal; 
         public string sVal; 
         public ExprNode eVal;
         public TreeNode tVal;
         public BlockNode lVal;
         public List<string> lsVal;
	 public GreatType dtVal;
       }

%using System.IO
%using Syntax_node_tree
%namespace LexScanner

%start progr

%token kBEGIN kEND kIF kTHEN kELSE kWHILE kDO kVAR kWRITE kWRITELN
%token ASSIGN SEMICOLUMN LPAREN RPAREN COLUMN COLON POINT  
%token PLUS MINUS MULT DIVIDE 
%token AND OR NOT LT GT EQ NE LE GE DIV MOD
%token <iVal> INTNUM 
%token <dVal> REALNUM 
%token <sVal> STRINGLITERAL
%token <sVal> ID
%token <dtVal> kREAL kINTEGER kBOOLEAN

%type <eVal> expr
%type <tVal> operator elsepart
%type <lVal> listoperator progr 
%type <lsVal> ident 
%type <dtVal> ktype kSimpleType

%left LT GT LE GE EQ NE
%left MINUS PLUS OR
%left MULT DIVIDE AND DIV MOD
%left UMINUS NOT

%%

progr   :
	{
		$$ = new Program(@$);
	}
	| defss kBEGIN listoperator kEND 
	{
		$$ = $1;
		foreach (Operator oper in $3.list)
			$$.list.Add(oper);
	}
	| error 
	{ 
		System.Console.WriteLine("BAD TEXT!!!");
		break;
	} 
	;

defss : defs 
	{
		$$ = new BlockOperator(@$);
		$$.list.Add($1);
	}
	|defss defs {
		$1.list.Add($2);
		$$ = $1;
	}
	|
	;
    
defs : kVAR ident COLON ktype SEMICOLUMN 
	{
		TipType type;
		if ($4 == "int")
			type = TipType.IntType;
		else if ($4 == "double")
			type = TipType.DoubleType;
		else if ($4 == "bool")
			type = TipType.BoolType;
		else
		{
			 // Error: unknown type
		}
		$$ = new VarDef(@$, $2, type);
	}
	;   

ident: ID 
	{
		if (GlobalStructures.isNameExists($1))
		{
			// Error: this name is already used
		}
		Ident Id = new Ident($1, @1);
		listVars.Add(Id);
		$$ = new List<Ident>();
		$$.Add(Id);
	}   
	|ident COLUMN ID 
	{
		if (GlobalStructures.isNameExists($3))
		{
		// Error: this name is already used
		}
		Ident Id = new Ident($3, @3);
		listVars.Add(Id);
		$1.Add(Id);
		$$ = $1;
	}
	;
    
listoperator : operator 
	{
		$$ = new BlockOperator(@$);
		$$.list.Add($1);
	}
	| listoperator SEMICOLUMN operator {
		$1.list.Add($2);
		$$ = $1;
	}
	;

ktype : kSimpleType
	| error 
	{ 
		System.Console.WriteLine("BAD GREATE TYPE");
		break;
	}
	;

kSimpleType : kREAL 
	{
		$$ = "double";
	} 
	| kINTEGER 
	{
		$$ = "int";
	}
	| kBOOLEAN
	{
		$$ = "bool" 
	}
	;

operator: {}
	| ID ASSIGN expr 
	{
		if (!GlobalStructures.isNameExists($1))
		{
			// Error: Undeclarated identifier
		}
        Ident Id = GlobalStructures.getIdentByName($1);
        $$ = new Assign(Id, $3, @3);
	}
	| kWHILE expr kDO operator 
	{
		if ($2.getType()!=TypType.Boolean)
		{
			// Error: Óñëîâèå äîëæíî èìåòü ëîãè÷åñêèé òèï
		}
		$$ = new While($2, $4, @$);
	}
	| kIF expr kTHEN operator elsepart 
	{
		if ($2.getType()!=TypType.Boolean)
		{
			// Error: Óñëîâèå äîëæíî èìåòü ëîãè÷åñêèé òèï
		}
		$$=new If($2,$4,$5,@$);
	}
	| kBEGIN listoperator kEND 
	{
		$$ = $2;
	}
	| kWRITE LPAREN expr RPAREN 
	{
		System.Console.Write($3);
	}
	| kWRITELN LPAREN expr RPAREN
	{
		System.Console.WriteLine($3);
	}
        ;

elsepart: 
	{
		$$ = null;
	}
	| kELSE operator {
		$$ = $2;
	}
	;

expr: INTNUM 
	{
		int i = int.Parse($1);
		$$ = new IntConst(i, @1);
	}
	| REALNUM 
	{
		double d = double.Parse($1);
		$$ = new DoubleConst(d, @1);
	}
	| STRINGLITERAL 
	{
		// Íåò ó íàñ òàêèõ!!!
	}
	| ID 
	{
		if (!GlobalStructures.isNameExists($1))
		{
			// Error: Undeclarated identifier
		}
		$$ = new Ident($1, @1);
	}
	| expr PLUS expr 
	{
		$$ = new BinExpression($1, $3, Op.Plus, @$);
	}
	| expr MINUS expr 
	{
		$$ = new BinExpression($1, $3, Op.Minus, @$);
	}
	| expr MULT expr 
	{
		$$ = new BinExpression($1, $3, Op.Mult, @$);
	}
	| expr DIVIDE expr 
	{
		$$ = new BinExpression($1, $3, Op.Divide, @$);
	}
	| expr DIV expr 
	{
		// Íå ïîääåðæèâàåòñÿ!
	}
	| expr MOD expr 
	{
		// Íå ïîääåðæèâàåòñÿ!
	}
	| expr AND expr 
	{
		if ($1.getType() != TipType.BoolType || $2.getType() != TipType.BoolType)
		{
			// Error: only for bool types
		}
		$$ = new BinExpression($1, $3, Op.And, @$);
	}
	| expr OR expr 
	{
		if ($1.getType() != TipType.BoolType || $2.getType() != TipType.BoolType)
		{
		    // Error: only for bool types
		}
		$$ = new BinExpression($1, $3, Op.Or, @$);
	}
	| expr LT expr 
	{
		$$ = new BinExpression($1, $3, Op.Less, @$);
	}
	| expr GT expr 
	{
		$$ = new BinExpression($1, $3, Op.More, @$);
	}
	| expr LE expr	
	{
		$$ = new BinExpression($1, $3, Op.LessEqual, @$);
	}
	| expr GE expr 
	{
		$$ = new BinExpression($1, $3, Op.MoreEqual, @$);       
	}
	| expr EQ expr
	{
		$$ = new BinExpression($1, $3, Op.Equal, @$);       
	}
	| expr NE expr 
	{
		$$ = new BinExpression($1, $3, Op.NotEqual, @$);        
	}
	| NOT expr 
	{
		if ($2.getType() != TipType.BoolType)
		{
		// Error: type is wrong.
		}
		$$ = new UnarExpression($2, Op.Not, @2);
	}
	| MINUS expr %prec UMINUS 
	{
		if ($2.getType() != TipType.IntType && $2.getType() != TipType.DoubleType)
		{
		    // Error: type is wrong.
		}
		$$ = new UnarExpression($2, Op.Minus, @2);
	} 
	| LPAREN expr RPAREN 
	{
		$$ = $2;
	}
	;

%%

Сканер

%namespace LexScanner
%using Syntax_node_tree;

Alpha 	[a-zA-Z_]
INTNUM  [0-9]+
REALNUM {INTNUM}\.{INTNUM}
ID [a-zA-Z_][a-zA-Z0-9_]* 

%x COMMENT
%x COMMENT1

%%

"{" { BEGIN(COMMENT);}
<COMMENT> "}" { BEGIN(INITIAL);}
<COMMENT> <<EOF>> { Console.WriteLine("Комментарий не закрыт");}
"(*" { BEGIN(COMMENT1);}
<COMMENT1> "*)" { BEGIN(INITIAL);}
<COMMENT1> <<EOF>> { Console.WriteLine("Комментарий не закрыт");}

":=" { return (int)Tokens.ASSIGN; }
";" { return (int)Tokens.SEMICOLUMN; }
"-" { return (int)Tokens.MINUS; }
"+" { return (int)Tokens.PLUS; }
"*" { return (int)Tokens.MULT; }
"/" { return (int)Tokens.DIVIDE; }
"<" { return (int)Tokens.LT; }
">" { return (int)Tokens.GT; }
"<=" { return (int)Tokens.LE; }
">=" { return (int)Tokens.GE; }
"=" { return (int)Tokens.EQ; }
"<>" { return (int)Tokens.NE; }
"(" { return (int)Tokens.LPAREN; }
")" { return (int)Tokens.RPAREN; }
"," { return (int)Tokens.COLUMN; }
":" { return (int)Tokens.COLON; }
"." { return (int)Tokens.POINT;  }


\'[^']*\' {
  yylval.sVal = yytext.Substring(1,yytext.Length-2);
  return (int)Tokens.STRINGLITERAL;
}

{ID}  { 
  int res = ScannerHelper.GetIDToken(yytext);
  string s = yytext.ToLower();
  if (s=="integer")
    yylval.dtVal.DType=DataType.INTTYPE;
  if (s == "real")
      yylval.dtVal.DType =DataType.DOUBLETYPE;
  if (res == (int)Tokens.ID)
	yylval.sVal = yytext;
  return res;
}

{INTNUM} { 
  yylval.iVal = int.Parse(yytext); 
  return (int)Tokens.INTNUM; 
}

{REALNUM} { 
  yylval.dVal = double.Parse(yytext,new System.Globalization.CultureInfo("en-US")); 
  return (int)Tokens.REALNUM; 
}

%{
  yylloc = new LexLocation(tokLin, tokCol, tokELin, tokECol);
%}

%%

class ScannerHelper 
{
  private static Dictionary<string,int> keywords;

  static ScannerHelper() 
  {
    keywords = new Dictionary<string,int>();
    keywords.Add("var",(int)Tokens.kVAR);
    keywords.Add("real",(int)Tokens.kREAL);
    keywords.Add("integer",(int)Tokens.kINTEGER);
    keywords.Add("boolean",(int)Tokens.kBOOLEAN);
    keywords.Add("begin",(int)Tokens.kBEGIN);
    keywords.Add("end",(int)Tokens.kEND);
    keywords.Add("if",(int)Tokens.kIF);
    keywords.Add("then",(int)Tokens.kTHEN);
    keywords.Add("else",(int)Tokens.kELSE);
    keywords.Add("do",(int)Tokens.kDO);
    keywords.Add("while",(int)Tokens.kWHILE);
    keywords.Add("write",(int)Tokens.kWRITE);
    keywords.Add("writeln",(int)Tokens.kWRITELN);
    keywords.Add("div",(int)Tokens.DIV);
    keywords.Add("mod",(int)Tokens.MOD);
    keywords.Add("and",(int)Tokens.AND);
    keywords.Add("or",(int)Tokens.OR);
    keywords.Add("not",(int)Tokens.NOT);				
  }
  public static int GetIDToken(string s)
  {
    s = s.ToLower();
	if (keywords.ContainsKey(s))
	{ 
	  return keywords[s];
	}  
	else
      return (int)Tokens.ID;
  }
  
}