public void FindsParentMember()
{
var parentscope = new Sharp_LR35902_Compiler.Scope();
parentscope.AddMember(TestMember);
var chiledscope = new Sharp_LR35902_Compiler.Scope(parentscope);
Assert.IsNotNull(chiledscope.GetMember("test"));
}
private static VariableMember getVariable(string name, Scope scope)
{
var existingvariable = scope.GetMember(name);
if (existingvariable == null)
{
throw new SyntaxException($"Varible {name} does not exist in the current scope.");
}
return(existingvariable);
}
public VariableMember GetMember(string name) => GetLocalMember(name) ?? ParentScope?.GetMember(name);
public static BlockNode CreateAST(IList <Token> tokens, BlockNode rootnode, ref int i, Scope previousScope)
{
var currentnode = rootnode;
var currentscope = new Scope(previousScope);
for (; i < tokens.Count; i++)
{
var token = tokens[i];
if (token.Type == Variable)
{
// Variable[++/--] or Variable = [Variable/Immediate]
var nexttoken = tokens[++i];
if (nexttoken.Type != Operator)
{
throw new SyntaxException("Expected operator after variable");
}
Token valuenode;
VariableMember assignedvariable;
switch (nexttoken.Value)
{
case "=":
i++;
var expression = CreateExpression(tokens, currentscope, ref i);
if (expression == null)
{
throw new SyntaxException($"Unknown expression after =");
}
getVariable(token.Value, currentscope); // Check it exists
//var existingvariable = currentscope.GetMember(token.Value);
//var immediatedatatype = GetImmedateDataType(expression);
//checkCanConvertTypes(immediatedatatype, existingvariable.DataType);
currentnode.AddChild(new VariableAssignmentNode(token.Value, expression));
i--;
break;
case "++":
currentnode.AddChild(new IncrementNode(token.Value));
break;
case "--":
currentnode.AddChild(new DecrementNode(token.Value));
break;
case "+=":
assignedvariable = getVariable(token.Value, currentscope);
valuenode = tokens[++i];
if (valuenode.Type == Variable)
{
var valuevariable = getVariable(valuenode.Value, currentscope);
currentnode.AddChild(new AdditionAssignmentNode(assignedvariable.Name, new VariableValueNode(valuevariable.Name)));
}
else if (valuenode.Type == Immediate)
{
var expr = CreateExpression(tokens, currentscope, ref i);
i--;
currentnode.AddChild(new AdditionAssignmentNode(assignedvariable.Name, new ShortValueNode(expr)));
}
break;
case "-=":
assignedvariable = getVariable(token.Value, currentscope);
valuenode = tokens[++i];
if (valuenode.Type == Variable)
{
var valuevariable = getVariable(valuenode.Value, currentscope);
currentnode.AddChild(new SubtractionAssignmentNode(assignedvariable.Name, new VariableValueNode(valuevariable.Name)));
}
else if (valuenode.Type == Immediate)
{
var exp = CreateExpression(tokens, currentscope, ref i);
i--;
currentnode.AddChild(new SubtractionAssignmentNode(assignedvariable.Name, new ShortValueNode(exp)));
}
break;
default: throw new SyntaxException("Expected operator");
}
}
else if (token.Type == DataType)
{
// DataType Variable = [Variable/Immediate]
var variabletoken = tokens[++i];
if (variabletoken.Type != Variable)
{
throw new SyntaxException("Expected variable name after data type");
}
var variabledatatype = BuiltIn.DataTypes.Get(token.Value);
if (variabledatatype == null)
{
throw new SyntaxException($"Datatype {token.Value} does not exist.");
}
var operatornode = tokens[++i];
if (operatornode.Value == ";" || operatornode.Value == "=")
{
if (currentscope.GetMember(variabletoken.Value) != null)
{
throw new SyntaxException($"Variable {variabletoken.Value} already exists in the current scope.");
}
currentnode.AddChild(new VariableDeclarationNode(token.Value, variabletoken.Value));
if (operatornode.Value == ";") // Just a decleration
{
currentnode.AddChild(new VariableAssignmentNode(variabletoken.Value, new ShortValueNode(0)));
currentscope.AddMember(new VariableMember(variabledatatype, variabletoken.Value));
continue;
}
}
if (operatornode.Value != "=")
{
throw new SyntaxException("Expected token '='");
}
var valuenode = tokens[++i];
var expression = CreateExpression(tokens, currentscope, ref i);
if (expression == null)
{
throw new SyntaxException($"Unexpected symbol on variable assignment '{valuenode.Value}'");
}
i--;
//var immediatedatatype = GetImmedateDataType(expression);
//checkCanConvertTypes(immediatedatatype, variabledatatype);
currentnode.AddChild(new VariableAssignmentNode(variabletoken.Value, expression));
currentscope.AddMember(new VariableMember(variabledatatype, variabletoken.Value));
}
else if (token.Type == ControlFlow)
{
switch (token.Value)
{
case "while": break;
case "do": break;
case "for": break;
case "return": break;
case "continue": break;
case "else": break;
case "if":
if (tokens[i + 1].Value != "(")
{
throw new SyntaxException("Expected expression after IF statement.");
}
i += 2;
var expression = CreateExpression(tokens, currentscope, ref i);
if (tokens[i].Value != "{")
{
throw new SyntaxException("Expected open block after IF statement.");
}
i++;
var iftrue = CreateAST(tokens, new BlockNode(), ref i, currentscope);
var iffalse = new BlockNode();
var elsetoken = tokens.Get(++i);
if (elsetoken?.Value == "else")
{
iffalse = CreateAST(tokens, iffalse, ref i, currentscope);
}
currentnode.AddChild(new IfNode(expression, iftrue, iffalse));
break;
case "goto":
var nextnode = tokens[++i];
if (nextnode.Type != Variable)
{
throw new SyntaxException("Expected label name after goto statement.");
}
currentnode.AddChild(new GotoNode(nextnode.Value));
break;
default: // Label
var colonindex = token.Value.IndexOf(':');
currentnode.AddChild(new LabelNode(token.Value.Substring(0, colonindex)));
break;
}
}
else if (token.Value == "*")
{
var addresstoken = tokens[++i];
if (addresstoken.Type != Immediate)
{
throw new SyntaxException("Expected address after pointer.");
}
var address = ParseImmediate(addresstoken.Value);
var equals = tokens[++i];
if (equals.Value != "=")
{
throw new SyntaxException("Expected assignment after memory address.");
}
i++;
var value = CreateExpression(tokens, currentscope, ref i);
currentnode.AddChild(new MemoryAssignmentNode(address, value));
}
else if (token.Value == "}")
{
return(rootnode);
}
}
return(rootnode);
}
