public SchemeLambdaTemplate( SchemeAST ast, ISchemeEnvironment currentEnv )
{
if (ast.children.Count < 2)
{
throw new SchemeWrongNumberOfArguments(String.Format("Lambda expects exactly two arguments. You have given me: {0}", ast.children.Count));
}
//really not beautiful, but this is the price we pay for using the AST data structure
if (ast.children[0].currentObject != SchemeVoid.instance) // this is false for lambdas with no arguments
{
_params.Add((SchemeSymbol)ast.children[0].currentObject);
foreach (SchemeAST child in ast.children[0].children)
{
_params.Add((SchemeSymbol)child.currentObject);
}
}
_implementation = new SchemeAST();
_lambdaEnv = currentEnv ;
for (int i = 1; i < ast.children.Count; i++)
{
_implementation.children.Add((SchemeAST)ast.children[i].Clone());
_implementation.children[_implementation.children.Count - 1].parent = ast;
}
}
public List<SchemeObject> evaluate(SchemeAST AST)
{
if (currentEnvironment == null)
{
currentEnvironment = root;
}
return evaluate(ref AST);
}
internal static List<SchemeObject> lookupSymbolsFromEnv( ref SchemeAST currentAST, ISchemeEnvironment environment )
{
List<SchemeObject> ret = new List<SchemeObject>();
ret.Add( environment.get( (SchemeSymbol) currentAST.currentObject ) );
// not nice, but it works
/* if( ret[0] == null ) // this holds true if the currentObjcet is NOT in the symbol table. Then it might either be an integer or a float and has not been redefined or the function is unknown
{
ret.RemoveAt( 0 );
int intValue;
var symbol = ( (SchemeSymbol) currentAST.currentObject ).value;
if( int.TryParse( symbol, out intValue ) )
{
ret.Add( new SchemeInteger( intValue ) );
}
else //TODO extend for floats
{
throw new SchemeUndefinedSymbolException( String.Format( "Undefined Symbol: {0}", symbol ) );
}
} */
foreach (SchemeAST child in currentAST.children)
{
if( child.currentObject.GetType() == typeof( SchemeSymbol ) )
{
var symbol = (SchemeSymbol) child.currentObject;
ret.Add( environment.get( symbol ) );
if( ret[ret.Count -1]== null ) //objcet is not in symbol list, check for integer and float!
{
throw new SchemeUndefinedSymbolException( String.Format( "Undefined Symbol: {0}", symbol.value ) );
}
}
else
{
ret.Add( child.currentObject );
}
}
return ret;
}
private bool updateToNextLevelChild(ref SchemeAST currentAst, ISchemeEnvironment environment)
{
Type type = currentAst.currentObject.GetType();
if (type == typeof(SchemeSymbol))
{
SchemeType t = environment.get((SchemeSymbol)currentAst.currentObject);
if (t == null)
{
throw new SchemeUndefinedSymbolException(String.Format("Undefined Symbol: {0}", currentAst.currentObject.ToString()), currentAst.fileName, currentAst.sourceLength, currentAst.sourceOffset);
}
Type obj = t.GetType();
if (obj == typeof(SchemeBuiltInLambda)) // or typeof if. this is needed for parts which should not be evaluated.
{
return false;
}
if (obj == typeof(SchemeBuiltInIf))
{
var tmpRoot = new SchemeAST();
var condition = currentAst.children[0];
var oldParent = condition.parent;
tmpRoot.children.Add(condition);
condition.parent = tmpRoot;
var evaluated = evaluate(ref tmpRoot); //evaluate the if condition
tmpRoot = new SchemeAST(currentAst, evaluated[0]);
currentAst.children[0] = tmpRoot;
return false;
}
}
foreach (SchemeAST child in currentAst.children)
{
if (child.children.Count != 0)
{
currentAst = child;
return true;
}
}
return false;
}
private void updateParent(ref SchemeAST currentAST, SchemeObject newValue)
{
/* if (currentAST.currentObject.GetType() == typeof(SchemeLambda))
{
// foreach (SchemeType obj in currrentEn )
foreach (string key in currentEnvironment.getDict().Keys)
{
currentEnvironment.parent().set(new SchemeSymbol(key), currentEnvironment.getDict()[key]);
}
} */
if (currentAST.hasOwnEnviornment)// && currentEnvironment.parent() != null )
{
/* if (newValue is SchemeLambda)
{
foreach (string key in currentEnvironment.getDict().Keys)
{
currentEnvironment.parent().set(new SchemeSymbol(key), currentEnvironment.getDict()[key]);
}
} */
currentEnvironment = currentEnvironment.parent();
}
int postition = currentAST.parent.children.IndexOf(currentAST);
currentAST.parent.children.Remove(currentAST);
// if( newValue != SchemeVoid.instance )
// {
var returnValue = new SchemeAST(currentAST.parent, newValue);
currentAST.parent.children.Insert(postition, returnValue);
// }
}
private SchemeType getType(ref SchemeAST ast, ISchemeEnvironment environment)
{
SchemeObject ret = ast.currentObject;
if (ast.currentObject.GetType() == typeof(SchemeSymbol))
{
ret = environment.get((SchemeSymbol)ret);
}
if (!(ret is SchemeType))
{
return null;
}
return (SchemeType)ret;
}
private ISchemeFunction getFunction(ref SchemeAST ast, ISchemeEnvironment environment)
{
SchemeObject ret = ast.currentObject;
if (ast.currentObject.GetType() == typeof(SchemeSymbol))
{
ret = environment.get((SchemeSymbol)ret);
}
if (!(ret is ISchemeFunction))
{
return null;
}
return (ISchemeFunction)ret;
}
private SchemeObject evaluateSchemeAST(ref SchemeAST ast, ISchemeEnvironment environment)
{
var func = getFunction(ref ast, environment);
if (func != null)
{
return func.evaluate(ref ast, this);
}
else
{
var type = getType(ref ast, environment);
if (type != null)
{
return type;
}
else
{
throw new SchemeNoSuchMethodException(String.Format("{0} is no valid Scheme Method!", ast.currentObject.ToString()));
}
}
}
public ISchemeEnvironment getClonedEnv(ISchemeEnvironment parent)
{
var tmp = new SchemeEnvironment(_symbolTable, parent);
return (ISchemeEnvironment)tmp;
}
public SchemeEnvironment(ISchemeEnvironment parent)
{
Debug.Assert(parent != null, "Parent must not be null! use SchemeEnvironmentroot.Singleton!");
_parent = parent;
}
public SchemeEnvironment(Dictionary<string, SchemeType> dict, ISchemeEnvironment parent)
{
_parent = parent;
_symbolTable = dict;
}
public void setParent(ISchemeEnvironment parent)
{
throw new NotImplementedException();
}
public ISchemeEnvironment getClonedEnv(ISchemeEnvironment parent)
{
return new SchemeEnvironment(_symbolTable, parent);
}
public void setParent(ISchemeEnvironment parent)
{
this._parent = parent;
}
public SchemeLambdaImpl(SchemeAST implementation, List<SchemeSymbol> _params, ISchemeEnvironment env)
{
this._implementation = implementation;
this._params = _params;
this._lambdaEnv = env;
}
public SchemeLambda( SchemeAST ast, ISchemeEnvironment currentEnv )
{
Debug.Assert( false, "Should never be called!" );
}