public object Cons(object pObject)
{
var deepCopy = new SharpList();
deepCopy.Add (pObject);
foreach (var item in this) {
deepCopy.Add (item);
}
return deepCopy;
}
public object Rest()
{
if (this.Count == 0) {
return null;
} else {
if (Count <= 1) {
return null;
}
var deepCopy = new SharpList ();
for(int i = 1; i < Count; i++) {
deepCopy.Add (this[i]);
}
return deepCopy;
}
}
SharpList ReadList()
{
var list = new SharpList ();
_indent++;
while (CurrentToken().type != TokenType.RIGHT_PAREN) {
object child = Read ();
list.Add (child);
//Console.WriteLine (GetIndentSpaces() + "Added " + child.ToString() + " to list");
}
Step (); // skip the right parenthesis
_indent--;
return list;
}
private object Let(SharpList pList, Scope pCurrentScope)
{
SharpVector bindingsVector = pList [1] as SharpVector;
if(bindingsVector == null) {
Error ("The first argument to let is not a bindings vector", pList);
}
Scope letScope = new Scope ("Let" + _letScopeCounter++, pCurrentScope);
#if LOG_SCOPES
Console.WriteLine ("Created new let scope: " + letScope.name);
#endif
for (int i = 0; i < bindingsVector.Count; i += 2) {
SymbolToken symbolToken = bindingsVector [i] as SymbolToken;
if(symbolToken == null) {
Error("Argument " + (i).ToString() + " in let binding is not a symbol", pList);
}
letScope.SetVar (symbolToken.value, Eval (bindingsVector[i + 1], pCurrentScope));
}
SharpList copy = new SharpList ();
for (int i = 2; i < pList.Count; i++) {
copy.Add(pList[i]);
}
object lastResult = null;
foreach(var item in copy) {
//Console.WriteLine("Time to eval " + item);
lastResult = Eval (item, letScope);
}
return lastResult;
}
private object Fn(SharpList pList, Scope pCurrentScope)
{
SharpVector argBindings = pList [1] as SharpVector;
if(argBindings == null) {
Error ("The first argument to fn is not a vector of args", pList);
}
SharpVector argBindingsDeepCopy = new SharpVector ();
foreach(var argBinding in argBindings) {
argBindingsDeepCopy.Add (argBinding);
}
SharpList body = new SharpList ();
for (int i = 2; i < pList.Count; i++) {
body.Add(pList[i]);
}
Scope closure = new Scope ("Closure" + _closureCounter++, pCurrentScope);
#if LOG_SCOPES
Console.WriteLine ("Created new closure: " + closure.name);
#endif
string functionName = "Fn" + _functionCounter++;
return new SharpFunction(args => {
Scope functionCallScope = new Scope ("FunctionCallScope" + _functionCallScopeCounter++, closure);
#if LOG_SCOPES
Console.WriteLine ("Created new function call scope: " + functionCallScope.name);
#endif
int argPos = 0;
for(int argBindingPos = 0; argBindingPos < argBindingsDeepCopy.Count; argBindingPos++) {
var argBinding = argBindingsDeepCopy[argBindingPos];
if(argBinding is ReservedToken && (argBinding as ReservedToken).type == TokenType.AMPERSAND) {
argBindingPos++;
SymbolToken finalSymbol = argBindingsDeepCopy[argBindingPos] as SymbolToken;
if(finalSymbol == null) {
Error ("Final arg binding after ampersand is not a symbol: " + argBindingsDeepCopy[argBindingPos], pList);
}
var restOfArgs = new SharpList ();
while (argPos < args.Length) {
restOfArgs.Add(args[argPos++]);
}
functionCallScope.SetVar(finalSymbol.value, restOfArgs);
break;
}
SymbolToken symbol = argBinding as SymbolToken;
if(symbol == null) {
Error("Arg binding is not a symbol: " + symbol, pList);
}
functionCallScope.SetVar(symbol.value, args[argPos++]);
}
// Console.WriteLine(functionName + " was called with " + args.Length + " arguments:");
// foreach(var arg in args) {
// if(arg == null) {
// Console.WriteLine("null");
// } else {
// Console.WriteLine(arg.ToString());
// }
// }
object lastResult = null;
foreach(var item in body) {
//Console.WriteLine("Time to eval " + item);
lastResult = Eval (item, functionCallScope);
}
return lastResult;
}, functionName);
}
private object CallMacro(SharpList pMacroForm, SharpList pInvokingList, Scope pCurrentScope)
{
SymbolToken macroNameSymbol = pMacroForm [1] as SymbolToken;
if (macroNameSymbol == null) {
Error("The first argument to macro is not a string", pInvokingList);
}
//Console.WriteLine ("Calling macro " + macroNameSymbol.value);
var argBindings = pMacroForm [2] as SharpVector;
if (argBindings == null) {
Error("The second argument to macro is not a vector of args", pInvokingList);
}
List<object> args = new List<object> ();
for (int i = 1; i < pInvokingList.Count; i++) {
args.Add (pInvokingList[i]);
}
int argPos = 0;
Scope macroScope = new Scope ("Macro scope " + _macroScopeCounter++, pCurrentScope);
for(int argBindingPos = 0; argBindingPos < argBindings.Count; argBindingPos++) {
var argBinding = argBindings [argBindingPos];
if(argBinding is ReservedToken && (argBinding as ReservedToken).type == TokenType.AMPERSAND) {
argBindingPos++;
SymbolToken finalSymbol = argBindings[argBindingPos] as SymbolToken;
if(finalSymbol == null) {
Error("Final arg binding after ampersand is not a symbol: " + argBindings[argBindingPos], pInvokingList);
}
var restOfArgs = new SharpList ();
while (argPos < args.Count) {
restOfArgs.Add(args[argPos++]);
}
macroScope.SetVar(finalSymbol.value, restOfArgs);
break;
}
SymbolToken symbol = argBinding as SymbolToken;
if (symbol == null) {
Error ("One of the bindings to the macro is not a symbol", pInvokingList);
}
macroScope.SetVar(symbol.value, args[argPos]);
#if MACRODEBUG
Console.WriteLine ("Setting " + symbol.value + " to " + args[argPos] + " at arg pos " + argPos);
#endif
argPos++;
}
List<object> compiledForms = new List<object> ();
for(int i = 3; i < pMacroForm.Count; i++) {
object compiledBody = CompileMacro(pMacroForm [i], macroScope);
compiledForms.Add (compiledBody);
}
#if MACRODEBUG
Console.WriteLine("Compiled macro " + macroNameSymbol.value + " to the following forms: ");
foreach(var form in compiledForms) {
if(form != null) {
Console.WriteLine(form.ToString ());
}
else {
Console.WriteLine("null");
}
}
#endif
object lastResult = null;
foreach(var form in compiledForms) {
//Console.WriteLine ("Eval form " + form.ToString());
lastResult = Eval (form, pCurrentScope);
}
return lastResult;
}