/// <summary>
/// functionDefine ::= def identifier '(' functionParameters ')' block
/// </summary>
/// <exception cref="DynException"></exception>
public DynAstNodeFunctionDefine MatchFunctionDefine()
{
var r = new DynAstNodeFunctionDefine();
var defLexeme = NextLexeme();
if (defLexeme.Token != DynToken.KeywordDef)
{
throw new DynException($"语法错误，不是有效的函数定义 {defLexeme}");
}
var idLexeme = NextLexeme();
if (idLexeme.Token != DynToken.Identifier)
{
throw new DynException($"语法错误，不是有效的函数标识符 {idLexeme}");
}
r.Name = idLexeme.Identifier;
var plt = NextLexeme();
if (plt.Token != DynToken.SymbolPareLeft)
{
throw new DynException($"语法错误，不是左括弧( {plt}");
}
r.Parameters = MatchFunctionParameters();
var prt = NextLexeme();
if (prt.Token != DynToken.SymbolPareRight)
{
throw new DynException($"语法错误，不是右括弧) {prt}");
}
r.Block = MatchBlock();
return(r);
}
/// <summary>
///
/// </summary>
/// <param name="fd"></param>
public void CreateFunction(DynAstNodeFunctionDefine fd)
{
var methodBuilder = mainTypeBuider.DefineMethod(
fd.Name,
MethodAttributes.Public | MethodAttributes.Static,
anyType,
fd.Parameters.Select(i => anyType).ToArray()
);
var milg = methodBuilder.GetILGenerator();
Dictionary <string, LocalBuilder> methodScope = new Dictionary <string, LocalBuilder>();
Dictionary <string, int> args = new Dictionary <string, int>();
for (int pi = 0; pi < fd.Parameters.Count; ++pi)
{
args.Add(fd.Parameters[pi].Identifier, pi);
}
foreach (var s in fd.Block.Statements)
{
switch (s.Type)
{
case DynAstType.Statement:
{
var ss = s as DynAstNodeStatement;
EmitExpression(ss.Expression, milg, methodScope, args);
if (ss.IsReturn)
{
milg.Emit(OpCodes.Ret);
//var r = milg.DeclareLocal(anyType);
//var nle = milg.DefineLabel();
//milg.Emit(OpCodes.Dup);
//milg.Emit(OpCodes.Isinst, typeof(int));
//milg.Emit(OpCodes.Ldnull);
//milg.Emit(OpCodes.Cgt);
//milg.Emit(OpCodes.Brfalse, nle);
//milg.Emit(OpCodes.Newobj, anyType.GetConstructor(new Type[] { typeof(int) }));
//milg.Emit(OpCodes.Stloc, r);
//milg.Emit(OpCodes.Ldloc, r);
//milg.Emit(OpCodes.Ret);
//milg.MarkLabel(nle);
//var sle = milg.DefineLabel();
//milg.Emit(OpCodes.Dup);
//milg.Emit(OpCodes.Isinst, typeof(string));
//milg.Emit(OpCodes.Ldnull);
//milg.Emit(OpCodes.Cgt);
//milg.Emit(OpCodes.Brfalse,sle);
//milg.Emit(OpCodes.Newobj, anyType.GetConstructor(new Type[] { typeof(string) }));
//milg.Emit(OpCodes.Stloc, r);
//milg.Emit(OpCodes.Ldloc, r);
//milg.Emit(OpCodes.Ret);
//milg.MarkLabel(sle);
//var e = milg.DeclareLocal(typeof(DynException));
//milg.Emit(OpCodes.Ldstr, $"语法错误，未支持的类型。");
//milg.Emit(OpCodes.Newobj, typeof(DynException).GetConstructor(new Type[] { typeof(string) }));
//milg.Emit(OpCodes.Stloc, e);
//milg.Emit(OpCodes.Ldloc, e);
//milg.ThrowException(typeof(DynException));
//milg.Emit(OpCodes.Ldnull);
//milg.Emit(OpCodes.Ret);
}
break;
}
default:
throw new DynException($"语法错误，函数内部出现非语句，{s.Type}");
}
}
}