public void SchemeASTTest()
{
SchemeAST root = new SchemeAST();
SchemeAST ast = new SchemeAST( root, SchemeNil.instance );
Assert.IsTrue( ast.parent == root );
SchemeAST child1 = new SchemeAST( ast, SchemeNil.instance );
SchemeAST child2 = new SchemeAST( child1, SchemeTrue.instance );
child1.children.Add( child2 );
ast.children.Add( child1 );
Assert.IsTrue( ast.children.Count == 1 );
Assert.IsTrue( ast.children[0].parent == ast );
Assert.IsTrue( ast.currentObject == SchemeNil.instance );
Assert.IsTrue( ast.children[0].children.Count == 1 );
Assert.IsTrue( ast.children[0].children[0] == child2 );
Assert.IsTrue( ast.children[0].children[0].parent == child1 );
Assert.IsTrue( ast.children[0].children[0].currentObject == SchemeTrue.instance );
SchemeAST clone = (SchemeAST)ast.Clone();
Assert.AreEqual( clone, ast );
// Assert.AreEqual( clone, ast );
}
public SchemeAST parseString( string input )
{
SchemeAST root = new SchemeAST();
SchemeAST currentParent = root;
var tokens = tokenize( input );
for( int i = 0; i < tokens.Count; i++ )
{
string token = tokens[i];
if( token == "(" )
{
var j = 1 + i;
if( tokens[j] == ")" ) //peek if void
{
currentParent.children.Add(new SchemeAST( currentParent, SchemeVoid.instance ));
i += 2;
}
var oldParent = currentParent;
currentParent = new SchemeAST( oldParent, makeSchemeObject( tokens[++i] ) ); //make new ast node and assign it to the parent. Also advance the counter!
oldParent.children.Add( currentParent );
}
else if( token == ")" )
{
currentParent = currentParent.parent; //jump up one level
}
else
{
currentParent.children.Add( new SchemeAST( currentParent, makeSchemeObject( token ) ) );
}
}
return root;
}
public List<SchemeObject> evaluate(SchemeAST AST)
{
if (currentEnvironment == null)
{
currentEnvironment = root;
}
return evaluate(ref AST);
}
public object Clone()
{
SchemeAST ast = new SchemeAST( _parent, currentObject );
ast.hasOwnEnviornment = this.hasOwnEnviornment;
foreach( SchemeAST child in children )
{
ast.children.Add( (SchemeAST) child.Clone() );
}
return ast;
}
internal List<SchemeObject> evaluate(ref SchemeAST currentAST)
{
var returnValue = new List<SchemeObject>();
if (currentAST.currentObject == SchemeVoid.instance)
{
for (int i = 0; i < currentAST.children.Count; i++)
{
var ast = (SchemeAST)currentAST.children[i];
int instructionCount = 0;
while (true)
{
Logger.writeLine(String.Format("Instruction: {0}", instructionCount++));
if (Logger.enableConsoleLog || Logger.enableLogfile)
{
ast.createTreeOutput();
}
if (updateToNextLevelChild(ref ast, this.currentEnvironment)) //this updates currentAST until the first AST object is found which contains leaf objects only
{
continue;
}
var evaluated = evaluateSchemeAST(ref ast, this.currentEnvironment); //evaluate the expression
if (evaluated == null)
{
continue;
}
updateParent(ref ast, evaluated); //replace currentAST with result
if (ast.parent.currentObject != SchemeVoid.instance)
{
ast = ast.parent; //ascend the tree again
}
else
{
returnValue.Add(evaluated);
break;
}
}
}
}
return returnValue;
}
public SchemeAST parseStringWithPos(string input, string filename)
{
SchemeAST root = new SchemeAST();
SchemeAST currentParent = root;
var tokens = tokenizeWithPos(input);
SchemeAST newToken;
for (int i = 0; i < tokens.Count; i++)
{
string token = tokens[i].token;
if (token == "(")
{
var j = 1 + i;
if (tokens[j].token == ")") //peek if void
{
newToken = new SchemeAST(currentParent, SchemeVoid.instance);
currentParent.children.Add(newToken);
newToken.sourceOffset = tokens[i].offset;
newToken.sourceLength = tokens[i].length;
i += 2;
}
var oldParent = currentParent;
currentParent = new SchemeAST(oldParent, makeSchemeObject(tokens[++i].token)); //make new ast node and assign it to the parent. Also advance the counter!
currentParent.sourceOffset = tokens[i].offset;
currentParent.sourceLength = tokens[i].length;
oldParent.children.Add(currentParent);
}
else if (token == ")")
{
currentParent = currentParent.parent; //jump up one level
}
else
{
currentParent.children.Add(new SchemeAST(currentParent, makeSchemeObject(token)));
}
}
return root;
}
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 SchemeAST( SchemeAST parent, SchemeObject currentObject )
{
// Debug.Assert( parent != null && currentObject != null );
_parent = parent;
this.currentObject = currentObject;
}
private void createTreeOutputHelper(string indent, bool last, SchemeAST caller)
{
Logger.write(indent);
if (last)
{
Logger.write("\\-");
indent += " ";
}
else
{
Logger.write("|-");
indent += "| ";
}
if (currentObject.ToString() == "")
{
Logger.write("<void>");
}
else
{
Logger.write(currentObject.ToString());
}
if( System.Diagnostics.Debugger.IsAttached )
{
treeSanityCheck();
}
if (caller == this)
{
Logger.writeLine(" <---");
}
else
{
Logger.write("\n");
}
for (int i = 0; i < children.Count; i++)
children[i].createTreeOutputHelper(indent, i == children.Count - 1, caller);
}
public SchemeAST()
{
_parent = null;
this.currentObject = SchemeVoid.instance;
}
public void updateParent(SchemeAST newParent)
{
_parent = newParent;
foreach (SchemeAST child in _children)
{
child.updateParent(this);
}
}