“预期的EOF”自定义编译器中的错误 [英] "Expected EOF" error in custom compiler
问题描述
所以我在C＃中使用一个名为algebra的自定义语言编写自己的编译器。
我正在学习本教程http://msdn.microsoft.com/en-us/magazine/cc136756。 aspx
这是编译器的源代码。
我认为编译器代码有问题。
代码很大所以我把它作为下载链接附加，如果你不想下载它们，你可以查看教程代码，因为我的代码基本相同。
https://www.dropbox.com/s/6h5fu7f6in3mtfw/Ast.cs
https ：//www.dropbox.com/s/lt6x8zjltq68q50/Parser.cs
https://www.dropbox.com/s/h84crc42472773s/Program.cs
https ：//www.dropbox.com/s/gkw2im5n1it28pb/Scanner.cs
https://www.dropbox.com/s/0gnx65to6pfna0y/CodeGen.cs
这是创建消息的代码（Parser.cs）：
public Parser（Collections.IList< object>代币）
{
此 .tokens = tokens;
此 .index = 0 ;
this .result = this .ParseStmt（）;
if （ this .index！= this .tokens.Count）
throw new System.Exception （ 期望的EOF）;
}
此代码扫描任何操作员标志（以'+'为例）（scanner.c）
顺便说一下，还有更多的代码。
case'+'：
input.Read（）;
this.result.Add（Scanner.Add）;
休息;
这个位只是一个枚举（Ast.cs）
// < bin_op> ：= + | - | * | /
public enum BinOp
{
Add ，
Sub，
Mul，
Div
}
CodeGen.cs
private void GenExpr（Expr expr，System.Type expectedType）
{
System.Type deliveredType;
if （expr StringLiteral）
{
deliverType = typeof （ string ）;
this .il.Emit（Emit.OpCodes.Ldstr，（（StringLiteral）expr）.Value）;
}
else if （expr 是 IntLiteral）
{
deliverType = typeof （ int ）;
this .il.Emit（Emit.OpCodes.Ldc_I4，（（IntLiteral）expr）.Value）;
}
else if （expr 是变量）
{
string ident =（（Variable）expr）.Ident;
deliveredType = this .TypeOfExpr（expr）;
if （！this.symbolTable.ContainsKey（ident））
{
throw new System.Exception（ 未声明的变量' + ident + '）;
}
this .il.Emit（Emit.OpCodes.Ldloc， this .symbolTable [IDENT]）;
}
else if （stmt 是打印）
{
这些是'写'和'读''语句
// write语句是System.Console.WriteLine的别名。
// 它使用字符串大小写
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 是 ReadInt）
{
this .il.Emit（Emit.OpCodes.Call， typeof （System.Console）.GetMethod（ ReadLine，System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Static， null ， new 系统.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 ））;
}
此处更多代码定义变量，表达式等。
/ * < expr> ：=< string>
* | < INT>
* | < arith_expr>
* | < IDENT>
* /
public abstract class Expr
{
}
// < string> ：=< string_elem> *
public class StringLiteral：Expr
{
public string 值;
}
// < int> ：=< digit> +
public class IntLiteral：Expr
{
public int 值;
}
// < ident> ：=< char> < ident_rest> *
// < ident_rest> ：=< char> | < digit>
public class 变量：Expr
{
public string Ident;
}
// < bin_expr> ：=< expr> < bin_op> < expr>
public class BinExpr：Expr
{
public Expr Left;
public Expr Right;
public BinOp Op;
}
关于运营商的更多信息（scanner.c）/ / b $ b < pre lang =c＃> #region ArithmiticConstants
// 表示arithmitic标记的常量。这可以
// 或者写成枚举。
public static readonly object Add = new object （）;
public static readonly < span class =code-keyword> object Sub = new object （）;
public static readonly < span class =code-keyword> object Mul = new object （）;
public static readonly < span class =code-keyword> object Div = new object （）;
public static readonly < span class =code-keyword> object Semi = new object （）;
public static readonly < span class =code-keyword> object Equal = new object （）;
#endregion
问题看起来无法对数字或变量执行任何数学运算。
所以例如我写这样的代码并尝试编译它然而我得到一个错误（预期的EOF）：
变量x = 9;
变量y = 10;
变量ans = x * y;
写ans;
这里输出应该是90但是编译器给出错误'EOF预期'
但是这样可行：
变量x = 9;
写x;
所以我可以确认语言有效
如果有人能帮助我，我将非常感激。
所以我很感激我得到的任何帮助。谢谢：）
so I am making my own compiler in C# for a custom Language called algebra.
I am following this tutorial http://msdn.microsoft.com/en-us/magazine/cc136756.aspx
Here is the source code of the compiler.
I think there is something wrong with the compiler code.
The code is quite big so I attach it as download links, if you don't want to download them you can look at the tutorial code as the code I have is basically the same.
https://www.dropbox.com/s/6h5fu7f6in3mtfw/Ast.cs
https://www.dropbox.com/s/lt6x8zjltq68q50/Parser.cs
https://www.dropbox.com/s/h84crc42472773s/Program.cs
https://www.dropbox.com/s/gkw2im5n1it28pb/Scanner.cs
https://www.dropbox.com/s/0gnx65to6pfna0y/CodeGen.cs
Here is the code that creates the message(Parser.cs):
public Parser(Collections.IList<object> tokens)
{
this.tokens = tokens;
this.index = 0;
this.result = this.ParseStmt();
if (this.index != this.tokens.Count)
throw new System.Exception("expected EOF");
}
This code scans for any operator signs(taking '+' as an example)(scanner.cs)
there is more code to this by the way.
case '+':
input.Read();
this.result.Add(Scanner.Add);
break;
This bit is just an enumeration(Ast.cs)
// <bin_op> := + | - | * | /
public enum BinOp
{
Add,
Sub,
Mul,
Div
}
CodeGen.cs
private void GenExpr(Expr expr, System.Type expectedType)
{
System.Type deliveredType;
if (expr is StringLiteral)
{
deliveredType = typeof(string);
this.il.Emit(Emit.OpCodes.Ldstr, ((StringLiteral)expr).Value);
}
else if (expr is IntLiteral)
{
deliveredType = typeof(int);
this.il.Emit(Emit.OpCodes.Ldc_I4, ((IntLiteral)expr).Value);
}
else if (expr is Variable)
{
string ident = ((Variable)expr).Ident;
deliveredType = this.TypeOfExpr(expr);
if (!this.symbolTable.ContainsKey(ident))
{
throw new System.Exception("undeclared variable '" + ident + "'");
}
this.il.Emit(Emit.OpCodes.Ldloc, this.symbolTable[ident]);
}
else if (stmt is Print)
{
These are the 'write' and 'read' statements
// the "write" 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));
}
more code here that defines variables ,expressions etc.
/* <expr> := <string>
* | <int>
* | <arith_expr>
* | <ident>
*/
public abstract class Expr
{
}
// <string> := " <string_elem>* "
public class StringLiteral : Expr
{
public string Value;
}
// <int> := <digit>+
public class IntLiteral : Expr
{
public int Value;
}
// <ident> := <char> <ident_rest>*
// <ident_rest> := <char> | <digit>
public class Variable : Expr
{
public string Ident;
}
// <bin_expr> := <expr> <bin_op> <expr>
public class BinExpr : Expr
{
public Expr Left;
public Expr Right;
public BinOp Op;
}
More on the operators (scanner.cs)
#region ArithmiticConstants
// Constants to represent arithmitic tokens. This could
// be alternatively written as an enum.
public static readonly object Add = new object();
public static readonly object Sub = new object();
public static readonly object Mul = new object();
public static readonly object Div = new object();
public static readonly object Semi = new object();
public static readonly object Equal = new object();
#endregion
the problem looks like it's not possible to perform any mathematical operations on either a number or variable.
so for example I write such code and try to compile it however I get an error(expected EOF):
variable x = 9;
variable y = 10;
variable ans = x * y;
write ans;
here the output should be 90 however the compiler gives an error 'EOF expected'
However this works:
variable x = 9;
write x;
so I can confirm the language works
I would be very grateful if anyone could help me.
So I appreciate any help that I get. Thanks :)
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