/// <summary>
/// Sets the value on the named field. Does not automatically add a field if missing.
/// </summary>
/// <param name="name"></param>
/// <param name="val"></param>
public override void SetField(string name, HeronValue val)
{
if (fields.HasName(name))
{
fields[name] = val;
}
else if (GetBase() != null)
{
GetBase().SetField(name, val);
}
else
{
throw new Exception("Field '" + name + "' does not exist");
}
}
private void GetFreeVars(VM vm, Statement st, Stack<string> boundVars, Scope result)
{
// InternalCount and store the names defined by this statement
int nNewVars = 0;
foreach (string name in st.GetDefinedNames())
{
++nNewVars;
boundVars.Push(name);
}
// Iterate over all names used by expressions in the statement
foreach (string name in st.GetUsedNames())
{
// Is this not a boundVar, and not already marked as a free var
if (!boundVars.Contains(name) && !result.HasName(name))
{
// Throws an exception if the name is not found
HeronValue v = vm.LookupName(name);
result.Add(new VarDesc(name), v);
}
}
// Recurse over all sub statements, getting the free vars
foreach (Statement child in st.GetSubStatements())
GetFreeVars(vm, child, boundVars, result);
// Pop all variables added by this variable
for (int i = 0; i < nNewVars; ++i)
boundVars.Pop();
}
private void GetFreeVars(VM vm, Statement st, Stack <string> boundVars, Scope result)
{
// InternalCount and store the names defined by this statement
int nNewVars = 0;
foreach (string name in st.GetDefinedNames())
{
++nNewVars;
boundVars.Push(name);
}
// Iterate over all names used by expressions in the statement
foreach (string name in st.GetUsedNames())
{
// Is this not a boundVar, and not already marked as a free var
if (!boundVars.Contains(name) && !result.HasName(name))
{
// Throws an exception if the name is not found
HeronValue v = vm.LookupName(name);
result.Add(new VarDesc(name), v);
}
}
// Recurse over all sub statements, getting the free vars
foreach (Statement child in st.GetSubStatements())
{
GetFreeVars(vm, child, boundVars, result);
}
// Pop all variables added by this variable
for (int i = 0; i < nNewVars; ++i)
{
boundVars.Pop();
}
}
public bool HasVar(string s)
{
for (int i = scopes.Count; i > 0; --i)
{
Scope tbl = scopes[i - 1];
if (tbl.HasName(s))
{
return(true);
}
}
return(false);
}
public HeronValue GetVar(string s)
{
for (int i = scopes.Count; i > 0; --i)
{
Scope tbl = scopes[i - 1];
if (tbl.HasName(s))
{
return(tbl[s]);
}
}
throw new Exception("No field named '" + s + "' could be found");
}
public bool SetVar(string s, HeronValue o)
{
for (int i = scopes.Count; i > 0; --i)
{
Scope tbl = scopes[i - 1];
if (tbl.HasName(s))
{
tbl[s] = o;
return(false);
}
}
return(false);
}
public HeronValue LookupName(string s)
{
// Look in the scopes starting with the innermost
// and moving to the outermost.
// The outermost scope contains the arguments
for (int i = scopes.Count; i > 0; --i)
{
Scope tbl = scopes[i - 1];
if (tbl.HasName(s))
{
return(tbl[s]);
}
}
// Nothing found in the local vars,
// So we look in the "this" pointer (called "self")
// Note that "self" may be a class instance, or a moduleDef
// instance
if (self != null)
{
HeronValue r = self.GetFieldOrMethod(s);
if (r != null)
{
return(r);
}
// Nothing found in the "this" pointer. So
// we look if it has an enclosing module instance pointer.
// And use that
ModuleInstance mi = self.GetModuleInstance();
if (mi != null)
{
r = mi.GetFieldOrMethod(s);
if (r != null)
{
return(r);
}
}
}
// Look to see if the name is a type in the current module definition.
if (moduleDef != null)
{
HeronType t = moduleDef.FindType(s);
if (t != null)
{
return(t);
}
// Look to see if the name is a type in one of the imported module definitions.
List <HeronType> candidates = new List <HeronType>();
foreach (ModuleDefn defn in moduleDef.GetImportedModuleDefns())
{
t = defn.FindType(s);
if (t != null)
{
candidates.Add(t);
}
}
if (candidates.Count > 1)
{
throw new Exception("Ambiguous name resolution. Multiple modules contain a type named " + s);
}
if (candidates.Count == 1)
{
return(candidates[1]);
}
}
return(null);
}
