private Stmt ParseStmt()
{
Stmt result;
if (this.index == this.tokens.Count)
{
throw new System.Exception("expected statement, got EOF");
}
// <stmt> := print <expr>
// <expr> := <string>
// | <int>
// | <arith_expr>
// | <ident>
if (this.tokens[this.index].Equals("print"))
{
this.index++;
Print print = new Print();
//Если есть текстовое описание
if (this.index < this.tokens.Count &&
this.tokens[this.index] is Text.StringBuilder)
{
print.Expression = this.ParseExpr();
}
if (this.index < this.tokens.Count &&
this.tokens[this.index] is string)
{
print.VarExpression = this.ParseExpr();
}
result = print;
}
else if (this.tokens[this.index].Equals("var"))
{
this.index++;
DeclareVar declareVar = new DeclareVar();
if (this.index < this.tokens.Count &&
this.tokens[this.index] is string)
{
declareVar.Ident = (string)this.tokens[this.index];
}
else
{
throw new System.Exception("expected variable name after 'var'");
}
this.index++;
if (this.index == this.tokens.Count ||
this.tokens[this.index] != Scanner.Equal)
{
throw new System.Exception("expected = after 'var ident'");
}
this.index++;
declareVar.Expression = this.ParseExpr();
result = declareVar;
}
else if (this.tokens[this.index].Equals("input"))
{
this.index++;
ReadValue readValue = new ReadValue();
//Если есть текстовое описание
if (this.index < this.tokens.Count &&
this.tokens[this.index] is Text.StringBuilder)
{
readValue.Exp = this.ParseExpr();
}
if (this.index < this.tokens.Count &&
this.tokens[this.index] is string)
{
readValue.Ident = (string)this.tokens[this.index++];
result = readValue;
}
else
{
throw new System.Exception("expected variable name after 'input'");
}
}
/*else if (this.tokens[this.index].Equals("read_int"))
* {
* this.index++;
* ReadValue readValue = new ReadValue();
*
* if (this.index < this.tokens.Count &&
* this.tokens[this.index] is string)
* {
* readValue.Ident = (string)this.tokens[this.index++];
* result = readValue;
* }
* else
* {
* throw new System.Exception("expected variable name after 'read_int'");
* }
* }*/
else if (this.tokens[this.index].Equals("for"))
{
this.index++;
ForNext forNext = new ForNext();
if (this.index < this.tokens.Count &&
this.tokens[this.index] is string)
{
forNext.Ident = (string)this.tokens[this.index];
}
else
{
throw new System.Exception("expected identifier after 'for'");
}
this.index++;
if (this.index == this.tokens.Count ||
this.tokens[this.index] != Scanner.Equal)
{
throw new System.Exception("for missing '='");
}
this.index++;
forNext.From = this.ParseExpr();
if (this.index == this.tokens.Count ||
!this.tokens[this.index].Equals("to"))
{
throw new System.Exception("expected 'to' after for");
}
this.index++;
forNext.To = this.ParseExpr();
/*if (this.index == this.tokens.Count ||
* !this.tokens[this.index].Equals("do"))
* {
* throw new System.Exception("expected 'do' after from expression in for next");
* }*/
this.index++;
forNext.Body = this.ParseStmt();
result = forNext;
if (this.index == this.tokens.Count ||
!this.tokens[this.index].Equals("next"))
{
throw new System.Exception("unterminated 'for' loop body");
}
this.index++;
}
else if (this.tokens[this.index].Equals("if"))
{
this.index++;
IfElse ifthen = new IfElse();
ifthen.Condition = new ConExpression();
//Запишем первый операнд в условии
if (this.index < this.tokens.Count &&
this.tokens[this.index] is string)
{
ifthen.Condition.Left = this.ParseExpr();
}
else
{
throw new System.Exception("expected identifier after 'if'");
}
// Запишем условный оператор
if (this.tokens[this.index] == Scanner.More) //Больше
{
ifthen.Condition.Operation = ConOperation.More;
}
else if (this.tokens[this.index] == Scanner.MoreEqual) //Больше-равно
{
ifthen.Condition.Operation = ConOperation.MoreEqual;
}
else if (this.tokens[this.index] == Scanner.Less) //Меньше
{
ifthen.Condition.Operation = ConOperation.Less;
}
else if (this.tokens[this.index] == Scanner.LessEqual) //Меньше-равно
{
ifthen.Condition.Operation = ConOperation.LessEqual;
}
else if (this.tokens[this.index] == Scanner.Equal) //Равенство
{
ifthen.Condition.Operation = ConOperation.Equal;
}
else
{
throw new System.Exception("missing condition operator");
}
//Запишем второй операнд в условии
this.index++;
ifthen.Condition.Right = this.ParseExpr();
if (this.index == this.tokens.Count ||
!this.tokens[this.index].Equals("then"))
{
throw new System.Exception("expected 'then' after if");
}
this.index++;
ifthen.BodyThen = this.ParseStmt();
if (this.index < this.tokens.Count && this.tokens[this.index].Equals("else"))
{
this.index++;
ifthen.BodyElse = this.ParseStmt();
}
result = ifthen;
if (this.index == this.tokens.Count ||
!this.tokens[this.index].Equals("endif"))
{
throw new System.Exception("unterminated 'if' body");
}
this.index++;
}
else if (this.tokens[this.index] is string)
{
//---------------------------------------------------------
// assignment
Assign assign = new Assign();
assign.Ident = (string)this.tokens[this.index++];
if (this.index == this.tokens.Count ||
this.tokens[this.index] != Scanner.Equal)
{
throw new System.Exception("expected '='");
}
this.index++;
assign.Expression = this.ParseExpr();
//Проверим наличие операции
if (this.tokens[this.index] != Scanner.Semi)
{
assign.Expression = this.ParseBinExpr(assign.Expression);
}
result = assign;
}
else
{
throw new System.Exception("parse error at token " + this.index + ": " + this.tokens[this.index]);
}
if (this.index < this.tokens.Count && this.tokens[this.index] == Scanner.Semi)
{
this.index++;
if (this.index < this.tokens.Count &&
!this.tokens[this.index].Equals("next") && !this.tokens[this.index].Equals("endif") && !this.tokens[this.index].Equals("else"))
{
Sequence sequence = new Sequence();
sequence.First = result;
sequence.Second = this.ParseStmt();
result = sequence;
}
}
return(result);
}
private void GenStmt(Stmt stmt)
{
if (stmt is Sequence)
{
Sequence seq = (Sequence)stmt;
this.GenStmt(seq.First);
this.GenStmt(seq.Second);
}
else if (stmt is DeclareVar)
{
// declare a local
DeclareVar declare = (DeclareVar)stmt;
this.symbolTable[declare.Ident] = this.il.DeclareLocal(this.TypeOfExpr(declare.Expr));
// set the initial value
Assign assign = new Assign();
assign.Ident = declare.Ident;
assign.Expr = declare.Expr;
this.GenStmt(assign);
}
else if (stmt is Assign)
{
Assign assign = (Assign)stmt;
this.GenExpr(assign.Expr, this.TypeOfExpr(assign.Expr));
this.Store(assign.Ident, this.TypeOfExpr(assign.Expr));
}
else if (stmt is Print)
{
// the "print" statement is an alias for System.Console.WriteLine.
// it uses the string case
this.GenExpr(((Print)stmt).Expr, typeof(string));
this.il.Emit(Emit.OpCodes.Call, typeof(System.Console).GetMethod("WriteLine", new System.Type[] { typeof(string) }));
}
else if (stmt is ReadInt)
{
this.il.Emit(Emit.OpCodes.Call, typeof(System.Console).GetMethod("ReadLine", System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Static, null, new System.Type[] { }, null));
this.il.Emit(Emit.OpCodes.Call, typeof(int).GetMethod("Parse", System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Static, null, new System.Type[] { typeof(string) }, null));
this.Store(((ReadInt)stmt).Ident, typeof(int));
}
//*******************
else if (stmt is mcIf)
{
mcIf mcif = (mcIf)stmt;
//this.GenExpr(mcif.compExpr, typeof(int));
Emit.Label Else = this.il.DefineLabel();
Emit.Label Then = this.il.DefineLabel();
Emit.Label Salida = this.il.DefineLabel();
if (mcif.compExpr is CompExpr)
{
CompExpr compExpr = (CompExpr)mcif.compExpr;
this.GenExpr(compExpr.Left, typeof(int));
this.GenExpr(compExpr.Rigth, typeof(int));
genCodComp(compExpr.Op, Then);
}
else
{
GenExpr(mcif.compExpr, typeof(string));
this.il.Emit(Emit.OpCodes.Ldc_I4, 0);
this.il.Emit(Emit.OpCodes.Bne_Un, Then);
}
if (mcif.Else != null)
{
this.il.Emit(Emit.OpCodes.Br, Else);
}
else
{
this.il.Emit(Emit.OpCodes.Br, Salida);
}
this.il.MarkLabel(Then);
GenStmt(mcif.Then);
this.il.Emit(Emit.OpCodes.Br, Salida);
this.il.MarkLabel(Else);
if (mcif.Else != null)
{
GenStmt(mcif.Else);
}
this.il.MarkLabel(Salida);
}
else if (stmt is WhileLoop)
{
WhileLoop whileLoop = (WhileLoop)stmt;
Emit.Label Body = this.il.DefineLabel();
Emit.Label Salida = this.il.DefineLabel();
Emit.Label Cond = this.il.DefineLabel();
this.il.MarkLabel(Cond);
if (whileLoop.Cond is CompExpr)
{
CompExpr compExpr = (CompExpr)whileLoop.Cond;
this.GenExpr(compExpr.Left, typeof(int));
this.GenExpr(compExpr.Rigth, typeof(int));
genCodComp(compExpr.Op, Body);
}
else
{
GenExpr(whileLoop.Cond, typeof(string));
this.il.Emit(Emit.OpCodes.Ldc_I4, 0);
this.il.Emit(Emit.OpCodes.Bne_Un, Body);
}
this.il.Emit(Emit.OpCodes.Br, Salida);
this.il.MarkLabel(Body);
GenStmt(whileLoop.Body);
this.il.Emit(Emit.OpCodes.Br, Cond);
this.il.MarkLabel(Salida);
}
//*******************
else if (stmt is ForLoop)
{
// example:
// for x = 0 to 100 do
// print "hello";
// end;
// x = 0
ForLoop forLoop = (ForLoop)stmt;
Assign assign = new Assign();
assign.Ident = forLoop.Ident;
assign.Expr = forLoop.From;
this.GenStmt(assign);
// jump to the test
Emit.Label test = this.il.DefineLabel();
this.il.Emit(Emit.OpCodes.Br, test);
// statements in the body of the for loop
Emit.Label body = this.il.DefineLabel();
this.il.MarkLabel(body);
this.GenStmt(forLoop.Body);
// to (increment the value of x)
this.il.Emit(Emit.OpCodes.Ldloc, this.symbolTable[forLoop.Ident]);
this.il.Emit(Emit.OpCodes.Ldc_I4, 1);
this.il.Emit(Emit.OpCodes.Add);
this.Store(forLoop.Ident, typeof(int));
// **test** does x equal 100? (do the test)
this.il.MarkLabel(test);
this.il.Emit(Emit.OpCodes.Ldloc, this.symbolTable[forLoop.Ident]);
this.GenExpr(forLoop.To, typeof(int));
this.il.Emit(Emit.OpCodes.Blt, body);
}
else
{
throw new System.Exception("imposible generar: " + stmt.GetType().Name);
}
}
private void GenStmt(Stmt stmt)
{
if (stmt is Sequence)
{
Sequence seq = (Sequence)stmt;
this.GenStmt(seq.First);
this.GenStmt(seq.Second);
}
else if (stmt is DeclareVar)
{
// declare a local
DeclareVar declare = (DeclareVar)stmt;
this.symbolTable[declare.Ident] = this.il.DeclareLocal(this.TypeOfExpr(declare.Expr));
// set the initial value
Assign assign = new Assign();
assign.Ident = declare.Ident;
assign.Expr = declare.Expr;
this.GenStmt(assign);
}
else if (stmt is Assign)
{
Assign assign = (Assign)stmt;
this.GenExpr(assign.Expr, this.TypeOfExpr(assign.Expr));
this.Store(assign.Ident, this.TypeOfExpr(assign.Expr));
}
else if (stmt is Print)
{
// the "print" statement is an alias for System.Console.WriteLine.
// it uses the string case
this.GenExpr(((Print)stmt).Expr, typeof(string));
this.il.Emit(Emit.OpCodes.Call, typeof(System.Console).GetMethod("WriteLine", new System.Type[] { typeof(string) }));
}
else if (stmt is ReadInt)
{
this.il.Emit(Emit.OpCodes.Call, typeof(System.Console).GetMethod("ReadLine", System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Static, null, new System.Type[] { }, null));
this.il.Emit(Emit.OpCodes.Call, typeof(int).GetMethod("Parse", System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Static, null, new System.Type[] { typeof(string) }, null));
this.Store(((ReadInt)stmt).Ident, typeof(int));
}
else if (stmt is ForLoop)
{
// example:
// for x = 0 to 100 do
// print "hello";
// end;
// x = 0
ForLoop forLoop = (ForLoop)stmt;
Assign assign = new Assign();
assign.Ident = forLoop.Ident;
assign.Expr = forLoop.From;
this.GenStmt(assign);
// jump to the test
Emit.Label test = this.il.DefineLabel();
this.il.Emit(Emit.OpCodes.Br, test);
// statements in the body of the for loop
Emit.Label body = this.il.DefineLabel();
this.il.MarkLabel(body);
this.GenStmt(forLoop.Body);
// to (increment the value of x)
this.il.Emit(Emit.OpCodes.Ldloc, this.symbolTable[forLoop.Ident]);
this.il.Emit(Emit.OpCodes.Ldc_I4, 1);
this.il.Emit(Emit.OpCodes.Add);
this.Store(forLoop.Ident, typeof(int));
// **test** does x equal 100? (do the test)
this.il.MarkLabel(test);
this.il.Emit(Emit.OpCodes.Ldloc, this.symbolTable[forLoop.Ident]);
this.GenExpr(forLoop.To, typeof(int));
this.il.Emit(Emit.OpCodes.Blt, body);
}
else
{
throw new System.Exception("don't know how to gen a " + stmt.GetType().Name);
}
}
private void GenStmt(Stmt stmt)
{
//Обработка элемента последовательности дерева
if (stmt is Sequence)
{
Sequence seq = (Sequence)stmt;
//Выполним обработку левой части дерева
this.GenStmt(seq.First);
//Выполним обработку правой части дерева
this.GenStmt(seq.Second);
}
//Обработка элемента дерева - "Объявление"
else if (stmt is DeclareVar)
{
// Добавим переменную в список переменных
DeclareVar declare = (DeclareVar)stmt;
this.varTable[declare.Ident] = this.TypeOfExpr(declare.Expression);
//Приведем элемент типа "Объевление" к типу "Присвоение"
Assign assign = new Assign();
assign.Ident = declare.Ident;
assign.Expression = declare.Expression;
//Запишем тип переменной
accum.Append(string.Format("\n{0} ", this.TypeOfExpr(declare.Expression).Name));
//Запустим на обработку
this.GenStmt(assign);
}
//Обработка элемента дерева - "Присвоение"
else if (stmt is Assign)
{
Assign assign = (Assign)stmt;
accum.Append(string.Format("{0}=", assign.Ident));
//Обработка правой части элемента
this.GenAssign(assign.Expression);
accum.Append(";");
}
//Обработка элемента дерева - "Вывод данных"
else if (stmt is Print)
{
Print print = (Print)stmt;
accum.Append(print.VarExpression != null
? string.Format("\nConsole.WriteLine(\"{0}\", {1});", this.GetExprValue(print.Expression),
this.GetExprValue(print.VarExpression))
: string.Format("\nConsole.WriteLine(\"{0}\");", this.GetExprValue(print.Expression)));
}
//Обработка элемента дерева - "Ввод данных"
else if (stmt is ReadValue)
{
ReadValue readValue = (ReadValue)stmt;
accum.Append(readValue.Exp != null
? string.Format("\n{0} = Console.ReadLine(\"{1}\");", readValue.Ident, this.GetExprValue(readValue.Exp))
: string.Format("\n{0} = Console.ReadLine();", readValue.Ident));
//Проверка, что переменная объявлена ранее
//CheckVariable
}
else if (stmt is IfElse)
{
IfElse ifElse = (IfElse)stmt;
string operation = string.Empty;
switch (ifElse.Condition.Operation)
{
case ConOperation.Equal: operation = "="; break;
case ConOperation.Less: operation = "<"; break;
case ConOperation.LessEqual: operation = "<="; break;
case ConOperation.More: operation = ">"; break;
case ConOperation.MoreEqual: operation = ">="; break;
}
accum.Append(string.Format("\nif ({0}{1}{2})", this.GetExprValue(ifElse.Condition.Left), operation, this.GetExprValue(ifElse.Condition.Right)));
if (ifElse.BodyThen != null)
{
accum.Append("\n{\n");
this.GenStmt(ifElse.BodyThen);
accum.Append("\n}");
}
if (ifElse.BodyElse != null)
{
if (ifElse.BodyThen == null)
{
throw new System.Exception("error if - else");
}
accum.Append("\nelse\n{\n");
this.GenStmt(ifElse.BodyElse);
accum.Append("\n}");
}
}
else if (stmt is ForNext)
{
ForNext forNext = (ForNext)stmt;
accum.Append(string.Format("\nfor("));
Assign assign = new Assign();
assign.Ident = forNext.Ident;
assign.Expression = forNext.From;
this.GenStmt(assign);
accum.Append(string.Format("{0}<{1};{2}++)", forNext.Ident, this.GetExprValue(forNext.To), forNext.Ident));
this.varTable[forNext.Ident] = typeof(int);
if (forNext.Body != null)
{
accum.Append("\n{");
this.GenStmt(forNext.Body);
accum.Append("\n}");
}
}
else
{
throw new System.Exception("Отсутствует инструкция для генерирования операции: " + stmt.GetType().Name);
}
}
private Stmt ParseStmt()
{
Stmt result = null;
if (this.index == this.tokens.Count)
{
throw new System.Exception("expected statement, got EOF");
}
// <stmt> := print <expr>
// <expr> := <string>
// | <int>
// | <arith_expr>
// | <ident>
if (this.tokens[this.index].Equals(languageSetting["End"]))
{
this.index++;
}
else if (this.tokens[this.index].Equals(languageSetting["Start"]))
{
this.index++;
return(ParseStmt());
}
else if (this.tokens[this.index].Equals(languageSetting["Print"]))
{
this.index++;
Print print = new Print();
print.Expr = this.ParseExpr();
result = print;
}
else if (this.tokens[this.index] == Scanner.Call)
{
VoidMethodCall vmc = new VoidMethodCall();
vmc.Expr = this.ParseExpr();
result = vmc;
}
else if (this.tokens[this.index].Equals(languageSetting["VariableDeclaration"]))
{
this.index++;
DeclareVar declareVar = new DeclareVar();
if (this.index < this.tokens.Count &&
this.tokens[this.index] is string)
{
declareVar.Ident = (string)this.tokens[this.index];
}
else
{
throw new System.Exception("expected variable name after 'var'");
}
this.index++;
if (this.index == this.tokens.Count ||
this.tokens[this.index] != Scanner.Equal)
{
throw new System.Exception("expected = after 'var ident'");
}
this.index++;
declareVar.Expr = this.ParseExpr();
result = declareVar;
}
else if (this.tokens[this.index].Equals(languageSetting["if"]))
{
this.index++;
IfCondition ifCon = new IfCondition();
ifCon.BooleanExp = this.ParseExpr();
if (!this.tokens[++this.index].Equals(languageSetting["Start"]))
{
throw new System.Exception("Start Expected");
}
ifCon.Body = this.ParseStmt();
if (!this.tokens[this.index++].Equals(languageSetting["End"]))
{
throw new System.Exception("End Expected");
}
result = ifCon;
}
else if (this.tokens[this.index].Equals(languageSetting["while"]))
{
this.index++;
WhileLoop whileLoop = new WhileLoop();
whileLoop.BooleanExp = this.ParseExpr();
if (!this.tokens[++this.index].Equals(languageSetting["Start"]))
{
throw new System.Exception("Start Expected");
}
whileLoop.Body = this.ParseStmt();
if (!this.tokens[this.index++].Equals(languageSetting["End"]))
{
throw new System.Exception("End Expected");
}
result = whileLoop;
}
else if (this.tokens[this.index].Equals("read_int"))
{
this.index++;
ReadInt readInt = new ReadInt();
if (this.index < this.tokens.Count &&
this.tokens[this.index] is string)
{
readInt.Ident = (string)this.tokens[this.index++];
result = readInt;
}
else
{
throw new System.Exception("expected variable name after 'read_int'");
}
}
else if (this.tokens[this.index].Equals("for"))
{
this.index++;
ForLoop forLoop = new ForLoop();
if (this.index < this.tokens.Count &&
this.tokens[this.index] is string)
{
forLoop.Ident = (string)this.tokens[this.index];
}
else
{
throw new System.Exception("expected identifier after 'for'");
}
this.index++;
if (this.index == this.tokens.Count ||
this.tokens[this.index] != Scanner.Equal)
{
throw new System.Exception("for missing '='");
}
this.index++;
forLoop.From = this.ParseSingleExpression();
if (this.index == this.tokens.Count ||
!this.tokens[this.index].Equals("to"))
{
throw new System.Exception("expected 'to' after for");
}
this.index++;
forLoop.To = this.ParseSingleExpression();
if (this.index == this.tokens.Count ||
!this.tokens[this.index].Equals("do"))
{
throw new System.Exception("expected 'do' after from expression in for loop");
}
this.index++;
forLoop.Body = this.ParseStmt();
result = forLoop;
if (this.index == this.tokens.Count ||
!this.tokens[this.index].Equals("end"))
{
throw new System.Exception("unterminated 'for' loop body");
}
this.index++;
}
else if (this.tokens[this.index] is string)
{
// assignment
Assign assign = new Assign();
assign.Ident = (string)this.tokens[this.index++];
if (this.index == this.tokens.Count ||
this.tokens[this.index] != Scanner.Equal)
{
throw new System.Exception("expected '='");
}
this.index++;
assign.Expr = this.ParseExpr();
result = assign;
}
else
{
throw new System.Exception("parse error at token " + this.index + ": " + this.tokens[this.index]);
}
if (this.index < this.tokens.Count && this.tokens[this.index] == Scanner.Semi)
{
this.index++;
if (this.index < this.tokens.Count &&
!this.tokens[this.index].Equals(languageSetting["End"]))
{
Sequence sequence = new Sequence();
sequence.First = result;
sequence.Second = this.ParseStmt();
result = sequence;
}
}
return(result);
}
private Stmt ParseStmt()
{
Stmt resultado;
if (this.indice == this.tokens.Count)
{
throw new System.Exception("se esperaban sentencias, se llego al final del archivo");
}
// <stmt> := print <expr>
// <expr> := <string>
// | <int>
// | <arith_expr>
// | <ident>
if (this.tokens[this.indice].Equals("print"))
{
this.indice++;
Print print = new Print();
print.Expr = this.ParseExpr();
resultado = print;
}
else if (this.tokens[this.indice].Equals("var"))
{
this.indice++;
DeclareVar declareVar = new DeclareVar();
if (this.indice < this.tokens.Count &&
this.tokens[this.indice] is string)
{
declareVar.Ident = (string)this.tokens[this.indice];
}
else
{
throw new System.Exception("Se esperaba nombre de variable despues de 'var'");
}
this.indice++;
if (this.indice == this.tokens.Count ||
this.tokens[this.indice] != Scanner.Igual)
{
throw new System.Exception("se esperaba = despues de 'var ident'");
}
this.indice++;
declareVar.Expr = this.ParseExpr();
resultado = declareVar;
}
else if (this.tokens[this.indice].Equals("read_int"))
{
this.indice++;
ReadInt readInt = new ReadInt();
if (this.indice < this.tokens.Count &&
this.tokens[this.indice] is string)
{
readInt.Ident = (string)this.tokens[this.indice++];
resultado = readInt;
}
else
{
throw new System.Exception("Se esperaba el nombre de la variable 'read_int'");
}
}
//*******************
else if (this.tokens[this.indice].Equals("if"))
{
this.indice++;
mcIf mcif = new mcIf();
Expr temp = ParseExpr();
if (this.tokens[this.indice] == Scanner.Eq || this.tokens[this.indice] == Scanner.Neq ||
this.tokens[this.indice] == Scanner.Gt || this.tokens[this.indice] == Scanner.Gte ||
this.tokens[this.indice] == Scanner.Lt || this.tokens[this.indice] == Scanner.Lte)
{
CompExpr compExpr = new CompExpr();
compExpr.Left = temp;
object op = this.tokens[this.indice++];
if (op == Scanner.Eq)
compExpr.Op = CompOp.Eq;
else if (op == Scanner.Neq)
compExpr.Op = CompOp.Neq;
else if (op == Scanner.Gt)
compExpr.Op = CompOp.Gt;
else if (op == Scanner.Gte)
compExpr.Op = CompOp.Gte;
else if (op == Scanner.Lt)
compExpr.Op = CompOp.Lt;
else if (op == Scanner.Lte)
compExpr.Op = CompOp.Lte;
compExpr.Rigth = ParseExpr();
temp = compExpr;
}
mcif.compExpr = temp;
if (this.indice == this.tokens.Count || !this.tokens[this.indice].Equals("then"))
{
throw new System.Exception("Se esperaba el identificador 'then' despues de 'if'");
}
this.indice++;
mcif.Then = ParseStmt();
if (this.tokens[this.indice].Equals("else"))
{
this.indice++;
mcif.Else = ParseStmt();
}
resultado = mcif;
if (this.indice == this.tokens.Count ||
!this.tokens[this.indice].Equals("end"))
{
throw new System.Exception("Sentencia if inconclusa");
}
this.indice++;
}
else if (this.tokens[this.indice].Equals("while"))
{
this.indice++;
WhileLoop whileLoop = new WhileLoop();
Expr temp = ParseExpr();
if (this.tokens[this.indice] == Scanner.Eq || this.tokens[this.indice] == Scanner.Neq ||
this.tokens[this.indice] == Scanner.Gt || this.tokens[this.indice] == Scanner.Gte ||
this.tokens[this.indice] == Scanner.Lt || this.tokens[this.indice] == Scanner.Lte)
{
CompExpr compExpr = new CompExpr();
compExpr.Left = temp;
object op = this.tokens[this.indice++];
if (op == Scanner.Eq)
compExpr.Op = CompOp.Eq;
else if (op == Scanner.Neq)
compExpr.Op = CompOp.Neq;
else if (op == Scanner.Gt)
compExpr.Op = CompOp.Gt;
else if (op == Scanner.Gte)
compExpr.Op = CompOp.Gte;
else if (op == Scanner.Lt)
compExpr.Op = CompOp.Lt;
else if (op == Scanner.Lte)
compExpr.Op = CompOp.Lte;
compExpr.Rigth = ParseExpr();
temp = compExpr;
}
whileLoop.Cond = temp;
if (this.indice == this.tokens.Count || !this.tokens[this.indice].Equals("do"))
{
throw new System.Exception("Se esperaba el identificador 'do' despues de 'while'");
}
this.indice++;
whileLoop.Body = ParseStmt();
resultado = whileLoop;
if (this.indice == this.tokens.Count ||
!this.tokens[this.indice].Equals("end"))
{
throw new System.Exception("sentencia while inconclusa");
}
this.indice++;
}
//*******************
else if (this.tokens[this.indice].Equals("for"))
{
this.indice++;
ForLoop forLoop = new ForLoop();
if (this.indice < this.tokens.Count &&
this.tokens[this.indice] is string)
{
forLoop.Ident = (string)this.tokens[this.indice];
}
else
{
throw new System.Exception("se esperaba un indentificador despues de 'for'");
}
this.indice++;
if (this.indice == this.tokens.Count ||
this.tokens[this.indice] != Scanner.Igual)
{
throw new System.Exception("no se encontro en la sentencia for '='");
}
this.indice++;
forLoop.From = this.ParseExpr();
if (this.indice == this.tokens.Count ||
!this.tokens[this.indice].Equals("to"))
{
throw new System.Exception("se epsaraba 'to' despues de for");
}
this.indice++;
forLoop.To = this.ParseExpr();
if (this.indice == this.tokens.Count ||
!this.tokens[this.indice].Equals("do"))
{
throw new System.Exception("se esperaba 'do' despues de la expresion en el ciclo for");
}
this.indice++;
forLoop.Body = this.ParseStmt();
resultado = forLoop;
if (this.indice == this.tokens.Count ||
!this.tokens[this.indice].Equals("end"))
{
throw new System.Exception("setencia for inconclusa");
}
this.indice++;
}
else if (this.tokens[this.indice] is string)
{
// assignment
Assign assign = new Assign();
assign.Ident = (string)this.tokens[this.indice++];
if (this.indice == this.tokens.Count ||
this.tokens[this.indice] != Scanner.Igual)
{
throw new System.Exception("se esperaba '='");
}
this.indice++;
assign.Expr = this.ParseExpr();
resultado = assign;
}
else
{
throw new System.Exception("Error en el token " + this.indice + ": " + this.tokens[this.indice]);
}
if (this.indice < this.tokens.Count && this.tokens[this.indice] == Scanner.PyC)
{
this.indice++;
if (this.indice < this.tokens.Count &&
!this.tokens[this.indice].Equals("end") && !this.tokens[this.indice].Equals("else"))
{
Sequence sequence = new Sequence();
sequence.First = resultado;
sequence.Second = this.ParseStmt();
resultado = sequence;
}
}
return resultado;
}
private Stmt ParseStmt()
{
Stmt result;
if (this.index == this.tokens.Count)
{
throw new System.Exception("expected statement, got EOF");
}
// <stmt> := print <expr>
// <expr> := <string>
// | <int>
// | <arith_expr>
// | <ident>
if (this.tokens[this.index].Equals("print"))
{
this.index++;
Print print = new Print();
print.Expr = this.ParseExpr();
result = print;
}
else if (this.tokens[this.index].Equals("var"))
{
this.index++;
DeclareVar declareVar = new DeclareVar();
if (this.index < this.tokens.Count &&
this.tokens[this.index] is string)
{
declareVar.Ident = (string)this.tokens[this.index];
}
else
{
throw new System.Exception("expected variable name after 'var'");
}
this.index++;
if (this.index == this.tokens.Count ||
this.tokens[this.index] != Scanner.Equal)
{
throw new System.Exception("expected = after 'var ident'");
}
this.index++;
declareVar.Expr = this.ParseExpr();
result = declareVar;
}
else if (this.tokens[this.index].Equals("read_int"))
{
this.index++;
ReadInt readInt = new ReadInt();
if (this.index < this.tokens.Count &&
this.tokens[this.index] is string)
{
readInt.Ident = (string)this.tokens[this.index++];
result = readInt;
}
else
{
throw new System.Exception("expected variable name after 'read_int'");
}
}
else if (this.tokens[this.index].Equals("for"))
{
this.index++;
ForLoop forLoop = new ForLoop();
if (this.index < this.tokens.Count &&
this.tokens[this.index] is string)
{
forLoop.Ident = (string)this.tokens[this.index];
}
else
{
throw new System.Exception("expected identifier after 'for'");
}
this.index++;
if (this.index == this.tokens.Count ||
this.tokens[this.index] != Scanner.Equal)
{
throw new System.Exception("for missing '='");
}
this.index++;
forLoop.From = this.ParseExpr();
if (this.index == this.tokens.Count ||
!this.tokens[this.index].Equals("to"))
{
throw new System.Exception("expected 'to' after for");
}
this.index++;
forLoop.To = this.ParseExpr();
if (this.index == this.tokens.Count ||
!this.tokens[this.index].Equals("do"))
{
throw new System.Exception("expected 'do' after from expression in for loop");
}
this.index++;
forLoop.Body = this.ParseStmt();
result = forLoop;
if (this.index == this.tokens.Count ||
!this.tokens[this.index].Equals("end"))
{
throw new System.Exception("unterminated 'for' loop body");
}
this.index++;
}
else if (this.tokens[this.index] is string)
{
// assignment
Assign assign = new Assign();
assign.Ident = (string)this.tokens[this.index++];
if (this.index == this.tokens.Count ||
this.tokens[this.index] != Scanner.Equal)
{
throw new System.Exception("expected '='");
}
this.index++;
assign.Expr = this.ParseExpr();
result = assign;
}
else
{
throw new System.Exception("parse error at token " + this.index + ": " + this.tokens[this.index]);
}
if (this.index < this.tokens.Count && this.tokens[this.index] == Scanner.Semi)
{
this.index++;
if (this.index < this.tokens.Count &&
!this.tokens[this.index].Equals("end"))
{
Sequence sequence = new Sequence();
sequence.First = result;
sequence.Second = this.ParseStmt();
result = sequence;
}
}
return(result);
}
private Stmt ParseStmt()
{
Stmt resultado;
if (this.indice == this.tokens.Count)
{
throw new System.Exception("se esperaban sentencias, se llego al final del archivo");
}
// <stmt> := print <expr>
// <expr> := <string>
// | <int>
// | <arith_expr>
// | <ident>
if (this.tokens[this.indice].Equals("print"))
{
this.indice++;
Print print = new Print();
print.Expr = this.ParseExpr();
resultado = print;
}
else if (this.tokens[this.indice].Equals("var"))
{
this.indice++;
DeclareVar declareVar = new DeclareVar();
if (this.indice < this.tokens.Count &&
this.tokens[this.indice] is string)
{
declareVar.Ident = (string)this.tokens[this.indice];
}
else
{
throw new System.Exception("Se esperaba nombre de variable despues de 'var'");
}
this.indice++;
if (this.indice == this.tokens.Count ||
this.tokens[this.indice] != Scanner.Igual)
{
throw new System.Exception("se esperaba = despues de 'var ident'");
}
this.indice++;
declareVar.Expr = this.ParseExpr();
resultado = declareVar;
}
else if (this.tokens[this.indice].Equals("read_int"))
{
this.indice++;
ReadInt readInt = new ReadInt();
if (this.indice < this.tokens.Count &&
this.tokens[this.indice] is string)
{
readInt.Ident = (string)this.tokens[this.indice++];
resultado = readInt;
}
else
{
throw new System.Exception("Se esperaba el nombre de la variable 'read_int'");
}
}
//*******************
else if (this.tokens[this.indice].Equals("if"))
{
this.indice++;
mcIf mcif = new mcIf();
Expr temp = ParseExpr();
if (this.tokens[this.indice] == Scanner.Eq || this.tokens[this.indice] == Scanner.Neq ||
this.tokens[this.indice] == Scanner.Gt || this.tokens[this.indice] == Scanner.Gte ||
this.tokens[this.indice] == Scanner.Lt || this.tokens[this.indice] == Scanner.Lte)
{
CompExpr compExpr = new CompExpr();
compExpr.Left = temp;
object op = this.tokens[this.indice++];
if (op == Scanner.Eq)
{
compExpr.Op = CompOp.Eq;
}
else if (op == Scanner.Neq)
{
compExpr.Op = CompOp.Neq;
}
else if (op == Scanner.Gt)
{
compExpr.Op = CompOp.Gt;
}
else if (op == Scanner.Gte)
{
compExpr.Op = CompOp.Gte;
}
else if (op == Scanner.Lt)
{
compExpr.Op = CompOp.Lt;
}
else if (op == Scanner.Lte)
{
compExpr.Op = CompOp.Lte;
}
compExpr.Rigth = ParseExpr();
temp = compExpr;
}
mcif.compExpr = temp;
if (this.indice == this.tokens.Count || !this.tokens[this.indice].Equals("then"))
{
throw new System.Exception("Se esperaba el identificador 'then' despues de 'if'");
}
this.indice++;
mcif.Then = ParseStmt();
if (this.tokens[this.indice].Equals("else"))
{
this.indice++;
mcif.Else = ParseStmt();
}
resultado = mcif;
if (this.indice == this.tokens.Count ||
!this.tokens[this.indice].Equals("end"))
{
throw new System.Exception("Sentencia if inconclusa");
}
this.indice++;
}
else if (this.tokens[this.indice].Equals("while"))
{
this.indice++;
WhileLoop whileLoop = new WhileLoop();
Expr temp = ParseExpr();
if (this.tokens[this.indice] == Scanner.Eq || this.tokens[this.indice] == Scanner.Neq ||
this.tokens[this.indice] == Scanner.Gt || this.tokens[this.indice] == Scanner.Gte ||
this.tokens[this.indice] == Scanner.Lt || this.tokens[this.indice] == Scanner.Lte)
{
CompExpr compExpr = new CompExpr();
compExpr.Left = temp;
object op = this.tokens[this.indice++];
if (op == Scanner.Eq)
{
compExpr.Op = CompOp.Eq;
}
else if (op == Scanner.Neq)
{
compExpr.Op = CompOp.Neq;
}
else if (op == Scanner.Gt)
{
compExpr.Op = CompOp.Gt;
}
else if (op == Scanner.Gte)
{
compExpr.Op = CompOp.Gte;
}
else if (op == Scanner.Lt)
{
compExpr.Op = CompOp.Lt;
}
else if (op == Scanner.Lte)
{
compExpr.Op = CompOp.Lte;
}
compExpr.Rigth = ParseExpr();
temp = compExpr;
}
whileLoop.Cond = temp;
if (this.indice == this.tokens.Count || !this.tokens[this.indice].Equals("do"))
{
throw new System.Exception("Se esperaba el identificador 'do' despues de 'while'");
}
this.indice++;
whileLoop.Body = ParseStmt();
resultado = whileLoop;
if (this.indice == this.tokens.Count ||
!this.tokens[this.indice].Equals("end"))
{
throw new System.Exception("sentencia while inconclusa");
}
this.indice++;
}
//*******************
else if (this.tokens[this.indice].Equals("for"))
{
this.indice++;
ForLoop forLoop = new ForLoop();
if (this.indice < this.tokens.Count &&
this.tokens[this.indice] is string)
{
forLoop.Ident = (string)this.tokens[this.indice];
}
else
{
throw new System.Exception("se esperaba un indentificador despues de 'for'");
}
this.indice++;
if (this.indice == this.tokens.Count ||
this.tokens[this.indice] != Scanner.Igual)
{
throw new System.Exception("no se encontro en la sentencia for '='");
}
this.indice++;
forLoop.From = this.ParseExpr();
if (this.indice == this.tokens.Count ||
!this.tokens[this.indice].Equals("to"))
{
throw new System.Exception("se epsaraba 'to' despues de for");
}
this.indice++;
forLoop.To = this.ParseExpr();
if (this.indice == this.tokens.Count ||
!this.tokens[this.indice].Equals("do"))
{
throw new System.Exception("se esperaba 'do' despues de la expresion en el ciclo for");
}
this.indice++;
forLoop.Body = this.ParseStmt();
resultado = forLoop;
if (this.indice == this.tokens.Count ||
!this.tokens[this.indice].Equals("end"))
{
throw new System.Exception("setencia for inconclusa");
}
this.indice++;
}
else if (this.tokens[this.indice] is string)
{
// assignment
Assign assign = new Assign();
assign.Ident = (string)this.tokens[this.indice++];
if (this.indice == this.tokens.Count ||
this.tokens[this.indice] != Scanner.Igual)
{
throw new System.Exception("se esperaba '='");
}
this.indice++;
assign.Expr = this.ParseExpr();
resultado = assign;
}
else
{
throw new System.Exception("Error en el token " + this.indice + ": " + this.tokens[this.indice]);
}
if (this.indice < this.tokens.Count && this.tokens[this.indice] == Scanner.PyC)
{
this.indice++;
if (this.indice < this.tokens.Count &&
!this.tokens[this.indice].Equals("end") && !this.tokens[this.indice].Equals("else"))
{
Sequence sequence = new Sequence();
sequence.First = resultado;
sequence.Second = this.ParseStmt();
resultado = sequence;
}
}
return(resultado);
}
private void GenStmt(Stmt stmt)
{
if (stmt is Sequence)
{
Sequence seq = (Sequence)stmt;
this.GenStmt(seq.First);
this.GenStmt(seq.Second);
}
else if (stmt is DeclareVar)
{
// declare a local
DeclareVar declare = (DeclareVar)stmt;
this.symbolTable[declare.Ident] = this.il.DeclareLocal(this.TypeOfExpr(declare.Expr));
// set the initial value
Assign assign = new Assign();
assign.Ident = declare.Ident;
assign.Expr = declare.Expr;
this.GenStmt(assign);
}
else if (stmt is Assign)
{
Assign assign = (Assign)stmt;
if (this.typefieldList.ContainsKey(assign.Ident))
{
if (!this.typefieldList[assign.Ident].IsStatic)
{
this.il.Emit(Emit.OpCodes.Ldarg_0);
}
}
// if(assign.Ident
this.GenExpr(assign.Expr, this.TypeOfExpr(assign.Expr));
this.Store(assign.Ident, this.TypeOfExpr(assign.Expr));
}
else if (stmt is Print)
{
// the "print" statement is an alias for System.Console.WriteLine.
// it uses the string case
this.GenExpr(((Print)stmt).Expr, typeof(string));
this.il.Emit(Emit.OpCodes.Call, typeof(System.Console).GetMethod("WriteLine", new System.Type[] { typeof(string) }));
// this.il.Emit(
}
else if (stmt is VoidMethodCall)
{
this.GenerteMethodCallCode((MethodCall)((VoidMethodCall)stmt).Expr);
}
else if (stmt is IfCondition)
{
IfCondition ifCon = (IfCondition)stmt;
this.GenExpr(ifCon.BooleanExp, /*harcoded for string */ typeof(string));
Emit.Label endOfIfBlock = this.il.DefineLabel();
if (((BinExpr)ifCon.BooleanExp).Op == BinOp.EqualTo)
{
this.il.Emit(Emit.OpCodes.Brfalse_S, endOfIfBlock);
}
else
{
this.il.Emit(Emit.OpCodes.Brtrue_S, endOfIfBlock);
}
this.GenStmt(ifCon.Body);
this.il.MarkLabel(endOfIfBlock);
// this.GenerteMethodCallCode((MethodCall)((VoidMethodCall)stmt).Expr);
}
else if (stmt is WhileLoop)
{
WhileLoop whileLoop = (WhileLoop)stmt;
Emit.Label whileBodyStart = this.il.DefineLabel();
Emit.Label whileBodyEnd = this.il.DefineLabel();
Emit.Label whileCondition = this.il.DefineLabel();
this.il.Emit(Emit.OpCodes.Br_S, whileBodyEnd);
this.il.MarkLabel(whileBodyStart);
this.GenStmt(whileLoop.Body);
this.il.MarkLabel(whileBodyEnd);
this.GenExpr(whileLoop.BooleanExp, /*harcoded for int */ typeof(int));
if (((BinExpr)whileLoop.BooleanExp).Op == BinOp.EqualTo)
{
this.il.Emit(Emit.OpCodes.Brtrue_S, whileBodyStart);
}
else
{
this.il.Emit(Emit.OpCodes.Brfalse_S, whileBodyStart);
}
}
// System.Diagnostics.Stopwatch st = new System.Diagnostics.Stopwatch();
else if (stmt is ReadInt)
{
this.il.Emit(Emit.OpCodes.Call, typeof(System.Console).GetMethod("ReadLine", System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Static, null, new System.Type[] { }, null));
this.il.Emit(Emit.OpCodes.Call, typeof(int).GetMethod("Parse", System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Static, null, new System.Type[] { typeof(string) }, null));
this.Store(((ReadInt)stmt).Ident, typeof(int));
}
else if (stmt is ForLoop)
{
// example:
// for x = 0 to 100 do
// print "hello";
// end;
// x = 0
ForLoop forLoop = (ForLoop)stmt;
Assign assign = new Assign();
assign.Ident = forLoop.Ident;
assign.Expr = forLoop.From;
this.GenStmt(assign);
// jump to the test
Emit.Label test = this.il.DefineLabel();
this.il.Emit(Emit.OpCodes.Br, test);
// statements in the body of the for loop
Emit.Label body = this.il.DefineLabel();
this.il.MarkLabel(body);
this.GenStmt(forLoop.Body);
// to (increment the value of x)
this.il.Emit(Emit.OpCodes.Ldloc, this.symbolTable[forLoop.Ident]);
this.il.Emit(Emit.OpCodes.Ldc_I4, 1);
this.il.Emit(Emit.OpCodes.Add);
this.Store(forLoop.Ident, typeof(int));
// **test** does x equal 100? (do the test)
this.il.MarkLabel(test);
this.il.Emit(Emit.OpCodes.Ldloc, this.symbolTable[forLoop.Ident]);
this.GenExpr(forLoop.To, typeof(int));
this.il.Emit(Emit.OpCodes.Blt, body);
}
else
{
throw new System.Exception("don't know how to gen a " + stmt.GetType().Name);
}
}
private Stmt ParseStmt()
{
Stmt result;
if (this.index == this.tokens.Count)
{
throw new System.Exception("expected statement, got EOF");
}
// <stmt> := print <expr>
// <expr> := <string>
// | <int>
// | <arith_expr>
// | <ident>
if (this.tokens[this.index].Equals("print"))
{
this.index++;
Print print = new Print();
print.Expr = this.ParseExpr();
result = print;
}
else if (this.tokens[this.index].Equals("var"))
{
this.index++;
DeclareVar declareVar = new DeclareVar();
if (this.index < this.tokens.Count &&
this.tokens[this.index] is string)
{
declareVar.Ident = (string)this.tokens[this.index];
}
else
{
throw new System.Exception("expected variable name after 'var'");
}
this.index++;
if (this.index == this.tokens.Count ||
this.tokens[this.index] != Scanner.Equal)
{
throw new System.Exception("expected = after 'var ident'");
}
this.index++;
declareVar.Expr = this.ParseExpr();
result = declareVar;
}
else if (this.tokens[this.index].Equals("read_int"))
{
this.index++;
ReadInt readInt = new ReadInt();
if (this.index < this.tokens.Count &&
this.tokens[this.index] is string)
{
readInt.Ident = (string)this.tokens[this.index++];
result = readInt;
}
else
{
throw new System.Exception("expected variable name after 'read_int'");
}
}
else if (this.tokens[this.index].Equals("for"))
{
this.index++;
ForLoop forLoop = new ForLoop();
if (this.index < this.tokens.Count &&
this.tokens[this.index] is string)
{
forLoop.Ident = (string)this.tokens[this.index];
}
else
{
throw new System.Exception("expected identifier after 'for'");
}
this.index++;
if (this.index == this.tokens.Count ||
this.tokens[this.index] != Scanner.Equal)
{
throw new System.Exception("for missing '='");
}
this.index++;
forLoop.From = this.ParseExpr();
if (this.index == this.tokens.Count ||
!this.tokens[this.index].Equals("to"))
{
throw new System.Exception("expected 'to' after for");
}
this.index++;
forLoop.To = this.ParseExpr();
if (this.index == this.tokens.Count ||
!this.tokens[this.index].Equals("do"))
{
throw new System.Exception("expected 'do' after from expression in for loop");
}
this.index++;
forLoop.Body = this.ParseStmt();
result = forLoop;
if (this.index == this.tokens.Count ||
!this.tokens[this.index].Equals("end"))
{
throw new System.Exception("unterminated 'for' loop body");
}
this.index++;
}
else if (this.tokens[this.index] is string)
{
// assignment
Assign assign = new Assign();
assign.Ident = (string)this.tokens[this.index++];
if (this.index == this.tokens.Count ||
this.tokens[this.index] != Scanner.Equal)
{
throw new System.Exception("expected '='");
}
this.index++;
assign.Expr = this.ParseExpr();
result = assign;
}
else
{
throw new System.Exception("parse error at token " + this.index + ": " + this.tokens[this.index]);
}
if (this.index < this.tokens.Count && this.tokens[this.index] == Scanner.Semi)
{
this.index++;
if (this.index < this.tokens.Count &&
!this.tokens[this.index].Equals("end"))
{
Sequence sequence = new Sequence();
sequence.First = result;
sequence.Second = this.ParseStmt();
result = sequence;
}
}
return result;
}
