//当该节点为func_definition时进入这个函数，把函数添加到全局符号表
private static void addFuncDefinition(NonterminalStackElement ee)
{
NonterminalStackElement func_declaratee_node = (NonterminalStackElement)ee.branches[1];
IdentifierStackElement func_identifier_node = (IdentifierStackElement)func_declaratee_node.branches[0];
string func_name = func_identifier_node.content;
Console.WriteLine("AddFunc: " + func_name);
FuncValue func = new FuncValue("func", func_name, ee, func_identifier_node.linenum);
//检查重复声明
if (globalSymbolTable.Keys.Contains(func_name))
{
throw new ExecutorException("已声明的变量或函数名" + func_name, func_identifier_node.linenum);
}
else
{
globalSymbolTable.Add(func_name, func);
}
}
//这里情况就不同了，上面是对应着+-*/四则运算的，所以char/string/数组 都不应该直接进行这些运算，但是他们可以被访问赋值，因此这里不做过多限制
/*
* factor→+factor |-factor|number|identifier more_identifier|(expr)|"string"|'char'
* more_identifier→ ε | [simple_expr] | () | (param_values)
* number→real_number |integer
*/
public static Value eval_factor(NonterminalStackElement factor_node, List <Dictionary <string, Value> > bindings_stack)
{
StackElement first_child = (StackElement)factor_node.branches[0];
//factor → number | "string" | 'char'
if (factor_node.branches.Count == 1)
{
//char
if (first_child.type_code == 7)
{
CharStackElement char_node = (CharStackElement)first_child;
return(new CharValue("char", true, char_node.content, char_node.linenum));
}
//string
else if (first_child.type_code == 8)
{
StringStackElement string_node = (StringStackElement)first_child;
return(new StringValue("string", true, string_node.content, string_node.linenum));
}
//number
else if (first_child.type_code == 3)
{
NonterminalStackElement number_node = (NonterminalStackElement)first_child;
return(eval_number(number_node));
}
else
{
throw new ExecutorException("eval_factor运行中发现factor文法发生了意想不到的变化");
}
}
//factor→+factor |-factor | identifier more_identifier
else if (factor_node.branches.Count == 2)
{
//+ - factor
if (first_child.type_code == 4)
{
int linenum = ((OtherTerminalStackElement)first_child).linenum;
OtherTerminalStackElement positive_or_negative = (OtherTerminalStackElement)first_child;
NonterminalStackElement child_factor_node = (NonterminalStackElement)factor_node.branches[1];
if (positive_or_negative.content == "+")
{
return(eval_factor(child_factor_node, bindings_stack));
}
//负号就要把值的符号颠倒
else
{
Value child_factor_node_value = eval_factor(child_factor_node, bindings_stack);
if (!Value.computable_types.Contains(child_factor_node_value.type))
{
throw new ExecutorException("不可在非数值类型前加上正号或者负号", linenum);
}
if (child_factor_node_value.type == "real")
{
RealValue value = (RealValue)child_factor_node_value;
value.value = -value.value;
return(value);
}
else if (child_factor_node_value.type == "int")
{
IntValue value = (IntValue)child_factor_node_value;
value.value = -value.value;
return(value);
}
else if (child_factor_node_value.type == "number")
{
NumberValue value = (NumberValue)child_factor_node_value;
value.value = -value.value;
return(value);
}
else
{
throw new ExecutorException("eval_factor运行中发现factor文法发生了意想不到的变化");
}
}
}
//factor→ identifier more_identifier
// more_identifier→ε | [simple_expr] | () | (param_values)
else
{
IdentifierStackElement identifier_node = (IdentifierStackElement)factor_node.branches[0];
int linenum = identifier_node.linenum;
NonterminalStackElement more_identifier_node = (NonterminalStackElement)factor_node.branches[1];
//检查是否定义
Dictionary <string, Value> bindings = ExecutorTools.findBindings(bindings_stack, identifier_node.content);
if (bindings != null)
{
//只是访问一个identifier 即 factor→ identifier
// more_identifier→ε
if (more_identifier_node.branches.Count == 0)
{
Value identifier_value = bindings[identifier_node.content];
return(identifier_value);
}
//应该是调用了一个不接受任何参数的函数比如foo()这样， more_identifier→ ()
else if (more_identifier_node.branches.Count == 2)
{
Value identifier_value = bindings[identifier_node.content];
if (identifier_value.type != "func")
{
throw new ExecutorException("标识符后带()应该是调用函数，但该标识符" + identifier_node.content + "对应函数并不存在", linenum);
}
FuncValue relevant_fucntion = (FuncValue)identifier_value;
Value return_value = relevant_fucntion.executeFunction();
return(return_value);
}
// 应该是调用了一个带参数的函数，或者是访问数组的某个元素 more_identifier → [simple_expr] | (param_values)
else if (more_identifier_node.branches.Count == 3)
{
Value identifier_value = bindings[identifier_node.content];
NonterminalStackElement second_element = (NonterminalStackElement)more_identifier_node.branches[1];
// more_identifier → [simple_expr] 要检查：第一，数组访问越界了没有；第二，访问的数组元素类型是否与要求的类型type相符合
if (second_element.name == "simple_expr")
{
//类型错误
if (!identifier_value.type.Contains("Array"))
{
throw new ExecutorException("标识符后带[ ]应该是访问数组某个元素，但该标识符" + identifier_node.content + "对应的并不是数组", linenum);
}
string array_type = identifier_value.type.Substring(0, identifier_value.type.Length - 5);
NonterminalStackElement simple_expr_node = second_element;
int index_to_access = ExecutorTools.get_array_len_from_simple_expr(simple_expr_node, bindings_stack);
//越界错误
if (index_to_access >= identifier_value.getArrayLen())
{
throw new ExecutorException("访问数组" + identifier_node.content + "时出现越界访问错误，数组长度只有" + identifier_value.getArrayLen(), linenum);
}
//eval要求就是获取到值，所以这里直接获取数组中元素的值，再转换为Value类型
else
{
if (identifier_value.type.Contains("int"))
{
return(new IntValue("int", false, identifier_value.getIntArrayElement(index_to_access).ToString(), linenum));
}
else if (identifier_value.type.Contains("real"))
{
return(new RealValue("real", false, identifier_value.getRealArrayElement(index_to_access).ToString(), linenum));
}
else if (identifier_value.type.Contains("int"))
{
return(new CharValue("char", false, identifier_value.getCharArrayElement(index_to_access).ToString(), linenum));
}
else
{
return(new StringValue("string", false, identifier_value.getStringArrayElement(index_to_access).ToString(), linenum));
}
}
}
// more_identifier → (param_values) 要检查：第一，函数签名是否符合（类型，次序）；第二，函数返回类型是否与要求的类型type相符合
else if (second_element.name == "param_values")
{
//类型错误
if (!identifier_value.type.Contains("func"))
{
throw new ExecutorException(identifier_node.content + "对应的并不是函数，无法调用", linenum);
}
FuncValue func_value = (FuncValue)identifier_value;
List <Value> args = new List <Value>();
NonterminalStackElement expr_node;
//param_values →expr,param_values|expr
NonterminalStackElement param_values_node = second_element;
while (param_values_node.branches.Count == 3)
{
expr_node = (NonterminalStackElement)param_values_node.branches[0];
param_values_node = (NonterminalStackElement)param_values_node.branches[2];
args.Add(eval_expr(expr_node, bindings_stack));
}
expr_node = (NonterminalStackElement)param_values_node.branches[0];
args.Add(eval_expr(expr_node, bindings_stack));
return(ExecutorTools.executeFunction(func_value, args, linenum));
}
else
{
throw new ExecutorException("文法发生了变化", linenum);
}
}
else
{
//Value relevant_value = Frame.curr_frame.local_bindings[identifier_node.content];
throw new ExecutorException("怎么到这的？", linenum);
}
}
throw new ExecutorException("语句中访问未定义的标识符" + identifier_node.content, linenum);
}
}
//factor→ ( expr )
else if (factor_node.branches.Count == 3)
{
NonterminalStackElement expr_node = (NonterminalStackElement)factor_node.branches[1];
return(eval_expr(expr_node, bindings_stack));
}
else
{
throw new ExecutorException("文法发生了变化", factor_node.linenum);
}
}
/*
* 初始化所有变量：规则（未给出初始化值initializer的，也就是只是声明的变量都赋0）
* declaratee→identifier | identifier[simple_expr] | identifier initializer | identifier [simple_expr] initializer | identifier[] initializer
* 接收参数declaratees：初始化数组/单个变量均可
* 可能出现错误：重复声明，void类型变量错误
* 声明单个变量：用数组给单个变量赋值，initializer值的类型与声明类型不符合
* 声明变量数组：用单个变量给数组变量赋值，initializer值的类型与声明类型不符合，initializer值的长度大于声明长度
* 可能有多个变量一起声明甚至初始化，但是他们类型必须相同（符合C语法）
*/
private static void initialize_declaratees(string type, List <NonterminalStackElement> declaratees, List <Dictionary <string, Value> > bindings_stack)
{
foreach (NonterminalStackElement declaratee in declaratees)
{
IdentifierStackElement id_node = (IdentifierStackElement)declaratee.branches[0];
string new_identifier = id_node.content;
int linenum = id_node.linenum;
//检查重复声明
Dictionary <string, Value> bindings = ExecutorTools.findBindings(bindings_stack, new_identifier, true);
//也就是已经有了同名变量
if (bindings != null)
{
throw new ExecutorException("重复声明已存在的变量" + new_identifier, id_node.linenum);
}
else
{
//那就在最上层准备声明
bindings = bindings_stack[bindings_stack.Count - 1];
//declaratee→identifier声明变量
if (declaratee.branches.Count == 1)
{
if (type == "int")
{
bindings.Add(new_identifier, new IntValue("int", false, "0", id_node.linenum));
}
else if (type == "real")
{
bindings.Add(new_identifier, new RealValue("real", false, "0.0", id_node.linenum));
}
else if (type == "char")
{
bindings.Add(new_identifier, new CharValue("char", false, "", id_node.linenum));
}
else if (type == "string")
{
bindings.Add(new_identifier, new StringValue("string", false, "", id_node.linenum));
}
else
{
throw new ExecutorException("试图声明一个void类型的变量" + new_identifier, id_node.linenum);
}
}
//declaratee→identifier initializer 声明并初始化变量
else if (declaratee.branches.Count == 2)
{
NonterminalStackElement initializer_node = (NonterminalStackElement)declaratee.branches[1];
if (initializer_node.branches.Count != 2)
{
throw new ExecutorException("试图用数组给单个变量" + new_identifier + "进行初始化", linenum);
}
//排除后，必然是initializer→=expr
NonterminalStackElement expr_node = (NonterminalStackElement)initializer_node.branches[1];
Value v = Evaluator.eval_expr(expr_node, mainFrameStack);
v = ExecutorTools.adjustType(type, v);
bindings.Add(new_identifier, v);
}
//declaratee→identifier[simple_expr] | identifier[] initializer声明定长数组，初始化auto自适应长度数组
else if (declaratee.branches.Count == 4)
{
StackElement third_child_of_last_declaratee = (StackElement)declaratee.branches[2];
//declaratee→identifier[] initializer
if (third_child_of_last_declaratee.type_code == 4)
{
//现在还不知道数组长度，要根据initializer算
int array_len;
NonterminalStackElement initializer_node = (NonterminalStackElement)declaratee.branches[3];
//initializer→ = expr |={ initializer_lst}
if (initializer_node.branches.Count != 4)
{
throw new ExecutorException("试图用单个变量给数组" + new_identifier + "进行初始化", linenum);
}
//排除后，必然是initializer→={initializer_lst}
NonterminalStackElement initializer_lst_node = (NonterminalStackElement)initializer_node.branches[2];
//获取initializer数组的长度 intializer_lst→expr | expr,initializer_lst | expr,
//获取给出的initializer中的值的集合
List <Value> given_values = new List <Value>();
while (initializer_lst_node.branches.Count == 3)
{
Value vv = Evaluator.eval_expr((NonterminalStackElement)initializer_lst_node.branches[0], mainFrameStack);
vv = ExecutorTools.adjustType(type, vv);
given_values.Add(vv);
initializer_lst_node = (NonterminalStackElement)initializer_lst_node.branches[2];
}
Value v = Evaluator.eval_expr((NonterminalStackElement)initializer_lst_node.branches[0], mainFrameStack);
v = ExecutorTools.adjustType(type, v);
given_values.Add(v);
initializer_lst_node = (NonterminalStackElement)initializer_lst_node.branches[2];
//根据给出的值数量，确定我们数组的长度
array_len = given_values.Count;
if (type == "int")
{
int[] arrayElements = new int[array_len];
for (int i = 0; i < array_len; i++)
{
if (given_values[i].type != "int")
{
throw new ExecutorException("用" + given_values[i].type + "类型给" + type + "类型数组变量" + new_identifier + "初始化", linenum);
}
IntValue value = (IntValue)given_values[i];
arrayElements[i] = value.value;
}
bindings.Add(new_identifier, new IntArrayValue("intArray", false, array_len, arrayElements, linenum));
}
else if (type == "real")
{
double[] arrayElements = new double[array_len];
for (int i = 0; i < array_len; i++)
{
if (given_values[i].type != "real")
{
throw new ExecutorException("用" + given_values[i].type + "类型给" + type + "类型数组变量" + new_identifier + "初始化", linenum);
}
RealValue value = (RealValue)given_values[i];
arrayElements[i] = value.value;
}
bindings.Add(new_identifier, new RealArrayValue("realArray", false, array_len, arrayElements, linenum));
}
else if (type == "char")
{
string[] arrayElements = new string[array_len];
for (int i = 0; i < array_len; i++)
{
if (given_values[i].type != "char")
{
throw new ExecutorException("用" + given_values[i].type + "类型给" + type + "类型数组变量" + new_identifier + "初始化", linenum);
}
CharValue value = (CharValue)given_values[i];
arrayElements[i] = value.value;
}
bindings.Add(new_identifier, new CharArrayValue("charArray", false, array_len, arrayElements, linenum));
}
else if (type == "string")
{
string[] arrayElements = new string[array_len];
for (int i = 0; i < array_len; i++)
{
if (given_values[i].type != "string")
{
throw new ExecutorException("用" + given_values[i].type + "类型给" + type + "类型数组变量" + new_identifier + "初始化", linenum);
}
StringValue value = (StringValue)given_values[i];
arrayElements[i] = value.value;
}
bindings.Add(new_identifier, new StringArrayValue("stringArray", false, array_len, arrayElements, linenum));
}
else
{
throw new ExecutorException("试图声明一个void类型的变量数组" + new_identifier, linenum);
}
}
//declaratee→identifier[simple_expr]
else
{
NonterminalStackElement simple_expr_node = (NonterminalStackElement)declaratee.branches[2];
int array_len = ExecutorTools.get_array_len_from_simple_expr(simple_expr_node, mainFrameStack);
if (type == "int")
{
int[] arrayElements = new int[array_len];
for (int i = 0; i < array_len; i++)
{
arrayElements[i] = 0;
}
bindings.Add(new_identifier, new IntArrayValue("intArray", false, array_len, arrayElements, linenum));
}
else if (type == "real")
{
double[] arrayElements = new double[array_len];
for (int i = 0; i < array_len; i++)
{
arrayElements[i] = 0.0;
}
bindings.Add(new_identifier, new RealArrayValue("realArray", false, array_len, arrayElements, linenum));
}
else if (type == "char")
{
string[] arrayElements = new string[array_len];
for (int i = 0; i < array_len; i++)
{
arrayElements[i] = "\0";
}
bindings.Add(new_identifier, new CharArrayValue("charArray", false, array_len, arrayElements, linenum));
}
else if (type == "string")
{
string[] arrayElements = new string[array_len];
for (int i = 0; i < array_len; i++)
{
arrayElements[i] = "";
}
bindings.Add(new_identifier, new StringArrayValue("stringArray", false, array_len, arrayElements, linenum));
}
else
{
throw new ExecutorException("试图声明一个void类型的变量数组" + new_identifier, linenum);
}
}
}
//declaratee→identifier [simple_expr] initializer
else if (declaratee.branches.Count == 5)
{
NonterminalStackElement simple_expr_node = (NonterminalStackElement)declaratee.branches[2];
//数组声明的长度
int array_len = ExecutorTools.get_array_len_from_simple_expr(simple_expr_node, mainFrameStack);
//现在还不知道被赋值的数组长度，要根据initializer算
NonterminalStackElement initializer_node = (NonterminalStackElement)declaratee.branches[4];
//initializer→ = expr | ={ initializer_lst}
if (initializer_node.branches.Count != 4)
{
throw new ExecutorException("试图用单个变量给数组" + new_identifier + "进行初始化", linenum);
}
//排除后，必然是initializer→={initializer_lst}
NonterminalStackElement initializer_lst_node = (NonterminalStackElement)initializer_node.branches[2];
//获取initializer数组的长度 intializer_lst→expr | expr,initializer_lst | expr,
//获取给出的initializer中的值的集合
List <Value> given_values = new List <Value>();
while (initializer_lst_node.branches.Count == 3)
{
Value vv = Evaluator.eval_expr((NonterminalStackElement)initializer_lst_node.branches[0], mainFrameStack);
vv = ExecutorTools.adjustType(type, vv);
given_values.Add(vv);
initializer_lst_node = (NonterminalStackElement)initializer_lst_node.branches[2];
}
Value v = Evaluator.eval_expr((NonterminalStackElement)initializer_lst_node.branches[0], mainFrameStack);
v = ExecutorTools.adjustType(type, v);
given_values.Add(v);
//赋值
if (given_values.Count > array_len)
{
throw new ExecutorException("数组" + new_identifier + "的初始值设定项长度" + given_values.Count + "大于声明的长度" + array_len, linenum);
}
if (type == "int")
{
int[] arrayElements = new int[array_len];
for (int i = 0; i < array_len; i++)
{
if (i < given_values.Count)
{
IntValue intv = (IntValue)given_values[i];
arrayElements[i] = intv.value;
}
else
{
arrayElements[i] = 0;
}
}
bindings.Add(new_identifier, new IntArrayValue("intArray", false, array_len, arrayElements, linenum));
}
else if (type == "real")
{
double[] arrayElements = new double[array_len];
for (int i = 0; i < array_len; i++)
{
if (i < given_values.Count)
{
RealValue intv = (RealValue)given_values[i];
arrayElements[i] = intv.value;
}
else
{
arrayElements[i] = 0.0;
}
}
bindings.Add(new_identifier, new RealArrayValue("realArray", false, array_len, arrayElements, linenum));
}
else if (type == "char")
{
string[] arrayElements = new string[array_len];
for (int i = 0; i < array_len; i++)
{
if (i < given_values.Count)
{
CharValue intv = (CharValue)given_values[i];
arrayElements[i] = intv.value;
}
else
{
arrayElements[i] = "\0";
}
}
bindings.Add(new_identifier, new CharArrayValue("charArray", false, array_len, arrayElements, linenum));
}
else if (type == "string")
{
string[] arrayElements = new string[array_len];
for (int i = 0; i < array_len; i++)
{
if (i < given_values.Count)
{
StringValue intv = (StringValue)given_values[i];
arrayElements[i] = intv.value;
}
else
{
arrayElements[i] = "";
}
}
bindings.Add(new_identifier, new StringArrayValue("stringArray", false, array_len, arrayElements, linenum));
}
else
{
throw new ExecutorException("试图声明一个void类型的变量数组" + new_identifier, linenum);
}
}
else
{
throw new ExecutorException("initialize_declaratee_withzero出现不正常的错误，可能是语法树解析declaratee出现问题");
}
}
}
}
public override string ToString()
{
string text = "";
if (type_code == 1)
{
IdentifierStackElement e = (IdentifierStackElement)this;
text += "第" + e.linenum + "行标识符";
text += e.content;
}
else if (type_code == 2)
{
IntStackElement e = (IntStackElement)this;
text += "第" + e.linenum + "行整数";
text += e.content;
}
else if (type_code == 3)
{
NonterminalStackElement e = (NonterminalStackElement)this;
text += "非终结符";
text += e.name;
//递归调用
foreach (StackElement s in e.branches)
{
text += Environment.NewLine;
for (int i = 1; i < s.layers; i++)
{
text += " ";
}
text += s.ToString();
}
}
else if (type_code == 4)
{
OtherTerminalStackElement e = (OtherTerminalStackElement)this;
text += "第" + e.linenum + "行终结符";
text += e.content;
}
else if (type_code == 5)
{
RealStackElement e = (RealStackElement)this;
text += "第" + e.linenum + "行实数";
text += e.content;
}
else if (type_code == 7)
{
CharStackElement e = (CharStackElement)this;
text += "第" + e.linenum + "行字符";
text += e.content;
}
else if (type_code == 8)
{
StringStackElement e = (StringStackElement)this;
text += "第" + e.linenum + "行字符串";
text += e.content;
}
else
{
StateStackElement e = (StateStackElement)this;
text += "状态" + e.state;
}
return(text);
}
//执行函数（传入参数，返回类型等等）
//注意创建一个新的bindings和Stack，且这个Stack目前只有globalBingdings->newBindings
//可能return null-->（仅在void函数中可能）
public static Value executeFunction(FuncValue func_value, List <Value> arguments_lst, int linenum)
{
//可以看到，所有的东西都是局部变量，因此函数调用结束这些Bindings都会自动free
List <Dictionary <string, Value> > binding_stack = new List <Dictionary <string, Value> >();
Dictionary <string, Value> local_bindings = new Dictionary <string, Value>();
binding_stack.Add(Executor.globalSymbolTable);
binding_stack.Add(local_bindings);
//获得返回类型
NonterminalStackElement return_type_node = (NonterminalStackElement)func_value.func_def_node.branches[0];
OtherTerminalStackElement specific_return_type_node = (OtherTerminalStackElement)return_type_node.branches[0];
string return_type = specific_return_type_node.content;
//获得函数名
NonterminalStackElement func_declaratee = (NonterminalStackElement)func_value.func_def_node.branches[1];
IdentifierStackElement identifier_node = (IdentifierStackElement)func_declaratee.branches[0];
string func_name = identifier_node.content;
List <string> params_lst = new List <string>();
//part1 传参
//先把实参传进来（加到local_bindings顺便做一个类型检查，函数签名和传入参数）
//func_declaratee →identifier()|identifier(param_lst)
if (func_declaratee.branches.Count == 4)
{
int index = 0;
NonterminalStackElement param_lst_node = (NonterminalStackElement)func_declaratee.branches[2];
//param_lst→param_declaration,param_lst | param_declaration
NonterminalStackElement param_declaration_node = (NonterminalStackElement)param_lst_node.branches[0];
while (param_lst_node.branches.Count == 3)
{
if (arguments_lst.Count <= index)
{
throw new ExecutorException("传入实参多于形参", linenum);
}
//param_declaration→type identifier|type identifier[simple_expr]
NonterminalStackElement type_node = (NonterminalStackElement)param_declaration_node.branches[0];
OtherTerminalStackElement specific_type_node = (OtherTerminalStackElement)type_node.branches[0];
IdentifierStackElement identifier_Node = (IdentifierStackElement)param_declaration_node.branches[1];
param_lst_node = (NonterminalStackElement)param_lst_node.branches[2];
param_declaration_node = (NonterminalStackElement)param_lst_node.branches[0];
string type = specific_type_node.content;
//传入数组会更特殊
if (param_declaration_node.branches.Count == 4)
{
type += "Array";
if (arguments_lst[index].type != type)
{
throw new ExecutorException("函数形参类型与实际传入参数类型不符", linenum);
}
NonterminalStackElement simple_expr_node = (NonterminalStackElement)param_declaration_node.branches[3];
if (arguments_lst[index].getArrayLen() > get_array_len_from_simple_expr(simple_expr_node, binding_stack))
{
throw new ExecutorException("传入的数组长度大于对应的形参数组长度", linenum);
}
}
//如果符合要求，那就在local_bindings增加定义
if (arguments_lst[index].type == type)
{
local_bindings.Add(identifier_Node.content, arguments_lst[index]);
index++;
}
else
{
throw new ExecutorException("函数形参类型与实际传入参数类型不符", linenum);
}
}
if ((index + 1) > arguments_lst.Count)
{
throw new ExecutorException("传入实参少于形参", linenum);
}
//最后一个参数，重复一遍上面的工作
NonterminalStackElement _type_node = (NonterminalStackElement)param_declaration_node.branches[0];
OtherTerminalStackElement _specific_type_node = (OtherTerminalStackElement)_type_node.branches[0];
IdentifierStackElement _identifier_Node = (IdentifierStackElement)param_declaration_node.branches[1];
string _type = _specific_type_node.content;
//传入数组会更特殊
if (param_declaration_node.branches.Count == 4)
{
_type += "Array";
if (arguments_lst[index].type != _type)
{
throw new ExecutorException("函数形参类型与实际传入参数类型不符", linenum);
}
NonterminalStackElement simple_expr_node = (NonterminalStackElement)param_declaration_node.branches[3];
if (arguments_lst[index].getArrayLen() > get_array_len_from_simple_expr(simple_expr_node, binding_stack))
{
throw new ExecutorException("传入的数组长度大于对应的形参数组长度", linenum);
}
}
//如果符合要求，那就在local_bindings增加定义
if (arguments_lst[index].type == _type)
{
local_bindings.Add(_identifier_Node.content, arguments_lst[index]);
index++;
}
else
{
throw new ExecutorException("函数形参类型与实际传入参数类型不符", linenum);
}
}
//func_declaratee →identifier() 这样的话local_bindings就不需要任何东西了
else
{
if (arguments_lst.Count != 0)
{
throw new ExecutorException("函数" + identifier_node.content + "不需要接受任何参数", linenum);
}
//do nothing
}
//part2 实际执行
//func_definition→type func_declaratee {stmt_lst} | type func_declaratee {}
if (func_value.func_def_node.branches.Count == 4)
{
if (return_type == "void")
{
return(null);
}
else
{
throw new ExecutorException("函数" + identifier_node.content + "没有返回任何值", linenum);
}
}
//func_definition → type func_declaratee {stmt_lst}
//stmt_lst → stmt stmt_lst | stmt
NonterminalStackElement stmt_lst_node = (NonterminalStackElement)func_value.func_def_node.branches[3];
Value return_value = executeStmtLst(stmt_lst_node, binding_stack);
//如果返回一个NullValue或者Null，那要检查是否是void
if (return_value == null || return_value.type == "null")
{
if (return_type == "void")
{
return(null);
}
else
{
throw new ExecutorException("函数" + func_name + "的返回值必须是" + return_type + "类型", linenum);
}
}
//返回不是Null，返回了一个实际的Value，那就要检查类型是否相符，检查返回类型不是void
else
{
if (return_type == "void")
{
throw new ExecutorException("函数" + func_name + "的返回值必须是null", linenum);
}
else
{
try
{
Value v = adjustType(return_type, return_value);
return(v);
}
//重新捕获调整再抛出
catch (ExecutorException ee)
{
throw new ExecutorException("函数" + func_name + "的返回值必须是" + return_type + "类型", linenum);
}
catch (Exception eee)
{
throw eee;
}
}
}
}
//执行某个具体的stmt，
// stmt → if_stmt| while_stmt|read_stmt| write_stmt|assign_stmt|declare_stmt| →compound_stmt|return_stmt|expr_stmt
// while_substmt →while_if_stmt| while_stmt|read_stmt| write_stmt|assign_stmt|declare_stmt| →while_compound_stmt|return_stmt|expr_stmt | break_stmt | continue_stmt
// 有三种可能，return了一个值，return;，或者真的没有return语句，分别对应Value，NullValue，Null
private static Value executeStmt(NonterminalStackElement specific_stmt_node, List <Dictionary <string, Value> > binding_stack)
{
string message = "";
//if_stmt→if(expr)compound_stmt more_ifelse
if (specific_stmt_node.name == "if_stmt")
{
NonterminalStackElement expr_node = (NonterminalStackElement)specific_stmt_node.branches[2];
Value expr_value = Evaluator.eval_expr(expr_node, binding_stack);
if (expr_value.getBoolean())
{
NonterminalStackElement compound_stmt = (NonterminalStackElement)specific_stmt_node.branches[4];
return(executeStmt(compound_stmt, binding_stack));
}
else
{
//more_ifelse→ε|else else_stmt
NonterminalStackElement more_if_else_node = (NonterminalStackElement)specific_stmt_node.branches[5];
if (more_if_else_node.branches.Count == 0)
{
return(null);
}
else
{
//else_stmt→if_stmt|compound_stmt
NonterminalStackElement else_stmt = (NonterminalStackElement)more_if_else_node.branches[1];
NonterminalStackElement specific_else_stmt = (NonterminalStackElement)else_stmt.branches[0];
return(executeStmt(specific_else_stmt, binding_stack));
}
}
//emmm突然优雅起来了？？？
}
//while_stmt→while(expr) while_compound_stmt
else if (specific_stmt_node.name == "while_stmt")
{
NonterminalStackElement expr_node = (NonterminalStackElement)specific_stmt_node.branches[2];
Value expr_value = Evaluator.eval_expr(expr_node, binding_stack);
Dictionary <string, Value> new_bindings = new Dictionary <string, Value>();
binding_stack.Add(new_bindings);
Executor.while_indexes.Add(binding_stack.Count);
//while_compound_stmt→{while_stmt_lst}|{}
//while_stmt_lst →while_substmt while_stmt_lst | while_substmt
NonterminalStackElement while_compound_stmt_node = (NonterminalStackElement)specific_stmt_node.branches[4];
while (expr_value.getBoolean())
{
if (while_compound_stmt_node.branches.Count == 2)
{
//do nothing
}
//while_compound_stmt→{while_stmt_lst}
else
{
NonterminalStackElement while_stmt_lst_node = (NonterminalStackElement)while_compound_stmt_node.branches[1];
Value v = executeStmtLst(while_stmt_lst_node, binding_stack);
//若提前执行return语句，直接结束while循环
if (v != null)
{
binding_stack.RemoveAt(binding_stack.Count - 1);
return(v);
}
}
expr_value = Evaluator.eval_expr(expr_node, binding_stack);
}
binding_stack.RemoveAt(binding_stack.Count - 1);
return(null);
}
//read_stmt→read identifier;| read identifier [ simple_expr ] ;
else if (specific_stmt_node.name == "read_stmt")
{
IdentifierStackElement identifier_node = (IdentifierStackElement)specific_stmt_node.branches[1];
if (specific_stmt_node.branches.Count == 3)
{
Dictionary <string, Value> bindings = findBindings(binding_stack, identifier_node.content);
if (bindings != null)
{
string type = bindings[identifier_node.content].type;
if (type.Contains("func") || type.Contains("bool"))
{
throw new ExecutorException("请检查您的读入目标是否有误，不可读入函数或者布尔类型值", specific_stmt_node.linenum);
}
else if (type.Contains("Array"))
{
int len = bindings[identifier_node.content].getArrayLen();
bindings[identifier_node.content] = ReaderHelper.read_array_value(type, identifier_node.linenum, len);
}
else
{
bindings[identifier_node.content] = ReaderHelper.read_single_value(type, identifier_node.linenum);
}
}
else
{
throw new ExecutorException("未定义的标识符" + identifier_node.content, identifier_node.linenum);
}
}
else
{
Dictionary <string, Value> bindings = findBindings(binding_stack, identifier_node.content);
if (bindings != null)
{
string type = bindings[identifier_node.content].type;
if (!type.Contains("Array"))
{
throw new ExecutorException("请检查您的读入目标是否有误，该标识符并不对应数组", specific_stmt_node.linenum);
}
NonterminalStackElement simple_expr_node = (NonterminalStackElement)specific_stmt_node.branches[3];
int index = get_array_len_from_simple_expr(simple_expr_node, binding_stack);
type = type.Substring(0, type.Length - 5);
Value read_value = ReaderHelper.read_single_value(type, identifier_node.linenum);
bindings[identifier_node.content].changeValueOfArray(index, read_value.getString());
}
else
{
throw new ExecutorException("未定义的标识符" + identifier_node.content, identifier_node.linenum);
}
}
return(null);
}
//write_stmt→write expr;
else if (specific_stmt_node.name == "write_stmt")
{
NonterminalStackElement expr_node = (NonterminalStackElement)specific_stmt_node.branches[1];
Value v = Evaluator.eval_expr(expr_node, binding_stack);
if (v.type == "func")
{
throw new ExecutorException("不支持write函数", specific_stmt_node.linenum);
}
WriterHelper.write_value(v, specific_stmt_node.linenum);
return(null);
}
//assign_stmt→identifier other_assign
else if (specific_stmt_node.name == "assign_stmt")
{
IdentifierStackElement identifier_node = (IdentifierStackElement)specific_stmt_node.branches[0];
NonterminalStackElement other_assign_node = (NonterminalStackElement)specific_stmt_node.branches[1];
//other_assign→= expr; | [simple_expr] = expr;
if (other_assign_node.branches.Count == 3)
{
NonterminalStackElement expr_node = (NonterminalStackElement)other_assign_node.branches[1];
Dictionary <string, Value> bindings = findBindings(binding_stack, identifier_node.content);
if (bindings != null)
{
string type = bindings[identifier_node.content].type;
if (type.Contains("func"))
{
throw new ExecutorException("不可给函数赋值", identifier_node.linenum);
}
else if (type.Contains("Array"))
{
throw new ExecutorException("不可给数组类型赋单个的值", identifier_node.linenum);
}
else
{
Value v = Evaluator.eval_expr(expr_node, binding_stack);
bindings[identifier_node.content] = adjustType(type, v);
}
}
else
{
throw new ExecutorException("未定义的标识符" + identifier_node.content, identifier_node.linenum);
}
}
//other_assign → [simple_expr] = expr;
else
{
NonterminalStackElement simple_expr_node = (NonterminalStackElement)other_assign_node.branches[1];
NonterminalStackElement expr_node = (NonterminalStackElement)other_assign_node.branches[4];
Dictionary <string, Value> bindings = findBindings(binding_stack, identifier_node.content);
if (bindings != null)
{
string type = bindings[identifier_node.content].type;
if (type.Contains("func"))
{
throw new ExecutorException("不可给函数赋值", specific_stmt_node.linenum);
}
else if (type.Contains("Array"))
{
Value v = Evaluator.eval_expr(expr_node, binding_stack);
type = type.Substring(0, type.Length - 5);
//检查赋值的类型和变量类型是否相符
v = adjustType(type, v);
int index = get_array_len_from_simple_expr(simple_expr_node, binding_stack);
bindings[identifier_node.content].changeValueOfArray(index, v.getString());
}
else
{
throw new ExecutorException("该变量并不是数组类型，无法赋值", identifier_node.linenum);
}
}
else
{
throw new ExecutorException("未定义的标识符" + identifier_node.content, identifier_node.linenum);
}
}
return(null);
}
//declare_stmt→type declaratee_lst;
else if (specific_stmt_node.name == "declare_stmt")
{
Executor.declareVaraible(specific_stmt_node, binding_stack);
return(null);
}
// compound_stmt→{stmt_lst}|{}
else if (specific_stmt_node.name == "compound_stmt")
{
if (specific_stmt_node.branches.Count == 2)
{
return(null);
}
//{stmt_lst}执行完就要出栈bindings
else
{
Dictionary <string, Value> new_local_bindings = new Dictionary <string, Value>();
binding_stack.Add(new_local_bindings);
//stmt_lst → stmt stmt_lst | stmt
NonterminalStackElement stmt_lst_node = (NonterminalStackElement)specific_stmt_node.branches[1];
Value v = executeStmtLst(stmt_lst_node, binding_stack);
//{stmt_lst}执行完就要出栈bindings
binding_stack.RemoveAt(binding_stack.Count - 1);
return(v);
}
}
// return_stmt→return expr; | return;
else if (specific_stmt_node.name == "return_stmt")
{
// return_stmt→ return;
if (specific_stmt_node.branches.Count == 2)
{
return(new NullValue(specific_stmt_node.linenum));
}
// return_stmt→return expr;
else
{
NonterminalStackElement expr_node = (NonterminalStackElement)specific_stmt_node.branches[1];
Value v = Evaluator.eval_expr(expr_node, binding_stack);
return(v);
}
}
//expr_stmt→expr;
else if (specific_stmt_node.name == "expr_stmt")
{
NonterminalStackElement expr_node = (NonterminalStackElement)specific_stmt_node.branches[0];
Value v = Evaluator.eval_expr(expr_node, binding_stack);
if (v == null)
{
return(null);
}
if (v.type == "func")
{
throw new ExecutorException("函数调用格式错误", specific_stmt_node.linenum);
}
else
{
return(null);
}
}
//while_if_stmt→if(expr)while_compound_stmt while_more_ifelse
else if (specific_stmt_node.name == "while_if_stmt")
{
NonterminalStackElement expr_node = (NonterminalStackElement)specific_stmt_node.branches[2];
Value expr_value = Evaluator.eval_expr(expr_node, binding_stack);
if (expr_value.getBoolean())
{
NonterminalStackElement compound_stmt = (NonterminalStackElement)specific_stmt_node.branches[4];
return(executeStmt(compound_stmt, binding_stack));
}
else
{
NonterminalStackElement more_if_else_node = (NonterminalStackElement)specific_stmt_node.branches[5];
//while_more_ifelse→ε|else while_else_stmt
if (more_if_else_node.branches.Count == 0)
{
return(null);
}
else
{
//while_else_stmt→while_if_stmt | while_compound_stmt
NonterminalStackElement else_stmt = (NonterminalStackElement)more_if_else_node.branches[1];
NonterminalStackElement specific_else_stmt = (NonterminalStackElement)else_stmt.branches[0];
return(executeStmt(specific_else_stmt, binding_stack));
}
}
}
//while_compound_stmt→{while_stmt_lst}|{}
else if (specific_stmt_node.name == "while_compound_stmt")
{
if (specific_stmt_node.branches.Count == 2)
{
return(null);
}
//{stmt_lst}执行完就要出栈bindings
else
{
Dictionary <string, Value> new_local_bindings = new Dictionary <string, Value>();
binding_stack.Add(new_local_bindings);
NonterminalStackElement stmt_lst_node = (NonterminalStackElement)specific_stmt_node.branches[1];
//while_stmt_lst →while_substmt while_stmt_lst | while_substmt
Value v = executeStmtLst(stmt_lst_node, binding_stack);
//{stmt_lst}执行完就要出栈bindings
binding_stack.RemoveAt(binding_stack.Count - 1);
return(v);
}
}
//break_stmt→break;
else if (specific_stmt_node.name == "break_stmt")
{
throw new ExecutorException("暂不实现");
}
//continue_stmt→continue;
else if (specific_stmt_node.name == "continue_stmt")
{
throw new ExecutorException("暂不实现");
}
else
{
throw new ExecutorException("Stmt/While_sub_stmt应该只有这些");
}
}
private void recursiveAddNodes(StackElement e, TreeViewItem newItem)
{
try
{
if (e.type_code == 6)
{
throw new ParserException("这个表示状态的栈元素不应该出现在Tree的递归子结点中！");
}
else if (e.type_code == 1)
{
IdentifierStackElement ele = (IdentifierStackElement)e;
newItem.Header = "第" + ele.linenum + "行的标识符：" + ele.content;
}
else if (e.type_code == 2)
{
IntStackElement ele = (IntStackElement)e;
newItem.Header = "第" + ele.linenum + "行的整数：" + ele.content;
}
else if (e.type_code == 3)
{
NonterminalStackElement ele = (NonterminalStackElement)e;
newItem.Header = "非终结符：" + ele.name;
}
else if (e.type_code == 4)
{
OtherTerminalStackElement ele = (OtherTerminalStackElement)e;
newItem.Header = "第" + ele.linenum + "行的终结符：" + ele.content;
}
else if (e.type_code == 5)
{
RealStackElement ele = (RealStackElement)e;
newItem.Header = "第" + ele.linenum + "行的实数：" + ele.content;
}
else if (e.type_code == 7)
{
CharStackElement ele = (CharStackElement)e;
newItem.Header = "第" + ele.linenum + "行的字符：" + ele.content;
}
else if (e.type_code == 8)
{
StringStackElement ele = (StringStackElement)e;
newItem.Header = "第" + ele.linenum + "行的字符串：" + ele.content;
}
else
{
throw new ParserException("这是啥栈元素？");
}
//若是终结符，branches就是空，若不是非终结符，它也终究会走到末端叶子节点，也就是非终结符，然后递归终止
if (e.branches.Count != 0)
{
foreach (StackElement ele in e.branches)
{
TreeViewItem new_node = new TreeViewItem();
newItem.Items.Add(new_node);
recursiveAddNodes(ele, new_node);
}
}
}
catch (ParserException pe)
{
MessageBox.Show(pe.err_msg);
}
catch (Exception ee)
{
MessageBox.Show(ee.ToString());
}
}