public void SetLocal(string key, Val value)
{
localDict[key] = value;
}
public void SetGlobal(string key, Val value)
{
globalDict[key] = value;
}
public override Val interp(Environment env)
{
Val result;
if (lexpr is IdC) // binding a variable
{
result = rexpr.interp(env);
env[((IdC)lexpr).sym] = result;
}
else if (lexpr is FuncC) // defining a function
{
FuncC lexprFunc = (FuncC)lexpr;
if (lexprFunc.func is IdC)
{
List <string> parms = new List <string>();
foreach (ExprC parm in lexprFunc.args)
{
if (parm is IdC)
{
parms.Add(((IdC)parm).sym);
}
else
{
throw new InterpException("Malformed function definition params");
}
}
result = new CloV((Environment)env.Clone(), rexpr, parms);
((CloV)result).env.SetLocal(((IdC)lexprFunc.func).sym, result); // allow recursion
env[((IdC)lexprFunc.func).sym] = result;
}
else
{
throw new InterpException("Malformed function definition name");
}
}
else if (lexpr is IndexC) // defining an array or setting an element
{
IndexC lexprArray = (IndexC)lexpr;
if (lexprArray.arr is IdC)
{
List <long> indices = new List <long>();
foreach (ExprC idx in lexprArray.indices)
{
Val idxVal = idx.interp(env);
if (idxVal is NumV)
{
indices.Add(((NumV)idxVal).num);
}
else
{
throw new InterpException("Non-numeric array index");
}
}
if (env.ContainsKey(((IdC)lexprArray.arr).sym)) // setting element
{
ArrV arr = lexprArray.arr.interp(env) as ArrV;
if (arr == null)
{
throw new InterpException("Indexing non-array");
}
result = rexpr.interp(env);
arr.SetValue(indices, result);
}
else // defining new array
{
result = new ArrV(indices, rexpr.interp(env));
env[((IdC)lexprArray.arr).sym] = result;
}
}
else
{
throw new InterpException("Malformed array definition name");
}
}
else
{
throw new InterpException("Binding with invalid lvalue");
}
return(result);
}
