// Build an assignment statement: i = 0, i += 1, i |= foo, etc
public static void BuildAssignment(IronyParser parser, Root root, Expression parentExpression, ParseTreeNode currentNode)
{
var assignment = new Assignment(parentExpression, currentNode.FindToken().Convert());
parentExpression.ChildExpressions.Add(assignment);
// Get the expression being assigned to
parser.ConsumeParseTree(root, assignment, currentNode.ChildNodes[0]);
// Determine what kind of assignment this is
switch(currentNode.ChildNodes[1].FindTokenAndGetText())
{
case "=":
assignment.AssignmentType = AssignmentType.Equal;
break;
case "+=":
assignment.AssignmentType = AssignmentType.Add;
break;
case "-=":
assignment.AssignmentType = AssignmentType.Subtract;
break;
case "*=":
assignment.AssignmentType = AssignmentType.Multiply;
break;
case "/=":
assignment.AssignmentType = AssignmentType.Divide;
break;
case "|=":
assignment.AssignmentType = AssignmentType.Or;
break;
case "&=":
assignment.AssignmentType = AssignmentType.And;
break;
}
// Get the value being assigned.
parser.ConsumeParseTree(root, assignment, currentNode.ChildNodes[2]);
}
/* Returns a CodeDOM statement representing an Assignment expression. */
public static CodeStatement Emit(Assignment assignment)
{
// The expression that is being assigned.
var assignedExpression = CodeDomEmitter.EmitCodeExpression(assignment.ChildExpressions[1]);
// Translate the assignment type to a CodeDOM one.
var codeOperator = CodeBinaryOperatorType.Add;
switch(assignment.AssignmentType)
{
case AssignmentType.Add:
codeOperator = CodeBinaryOperatorType.Add;
break;
case AssignmentType.And:
codeOperator = CodeBinaryOperatorType.BitwiseAnd;
break;
case AssignmentType.Or:
codeOperator = CodeBinaryOperatorType.BitwiseOr;
break;
case AssignmentType.Divide:
codeOperator = CodeBinaryOperatorType.Divide;
break;
case AssignmentType.Multiply:
codeOperator = CodeBinaryOperatorType.Multiply;
break;
case AssignmentType.Subtract:
codeOperator = CodeBinaryOperatorType.Subtract;
break;
}
/* Variables that are immediately assigned a value upon explicit declaration such as:
* int i = 10
* require a different CodeDOM statement than the normal assignment statement. */
if (assignment.ChildExpressions[0] is ExplicitVariableDeclaration)
{
var variable = assignment.ChildExpressions[0] as ExplicitVariableDeclaration;
var codeType = new CodeTypeReference();
codeType.BaseType = variable.TypeName;
foreach (String e in variable.GenericTypes)
codeType.TypeArguments.Add(new CodeTypeReference(e));
if (assignment.AssignmentType == AssignmentType.Equal)
{
return new CodeVariableDeclarationStatement(codeType, variable.Name, // The declaration
assignedExpression); // The assignment
}
else
{
// If we got this far, the validator missed that int i += x is not valid.
// Since this should have been caught prior to reaching the generator, this is a failure state.
throw new NotImplementedException();
}
}
else // Normal assignment (ex i = 1)
{
var left = CodeDomEmitter.EmitCodeExpression(assignment.ChildExpressions[0]);
if (assignment.AssignmentType == AssignmentType.Equal)
{
// A simple assignment: left = assignedExpression
return new CodeAssignStatement(left, // Left operand
assignedExpression); // Right operand
}
else
{
// Some other type of assignment, such as left += assignedExpression
// We need to create the appropriate codedom binary expression first.
var addOp = new CodeBinaryOperatorExpression();
addOp.Left = left;
addOp.Right = assignedExpression;
addOp.Operator = codeOperator;
return new CodeAssignStatement(left, addOp);
}
}
}
