static bool AddVisitCode(EasyMethod m, FieldInfo field, EasyExpression var, List <CodeStatement> assertions, bool transformer)
{
EasyExpression prop = var.Property(GetPropertyName(field.Name));
EasyExpression nodeStack = Easy.Var("nodeStack");
if (field.FieldType.FullName.StartsWith("System.Collections.Generic.List"))
{
Type elType = field.FieldType.GetGenericArguments()[0];
if (!typeof(INode).IsAssignableFrom(elType))
{
return(false);
}
assertions.Add(AssertIsNotNull(prop));
string code;
if (transformer)
{
code = CreateTransformerLoop(GetCode(prop), ConvertType(elType).BaseType);
}
else
{
code =
"\t\t\tforeach (" + ConvertType(elType).BaseType + " o in " + GetCode(prop) + ") {\n" +
"\t\t\t\tDebug.Assert(o != null);\n" +
"\t\t\t\to.AcceptVisitor(this, data);\n" +
"\t\t\t}";
}
m.Statements.Add(new CodeSnippetStatement(code));
return(true);
}
if (!typeof(INode).IsAssignableFrom(field.FieldType))
{
return(false);
}
assertions.Add(AssertIsNotNull(prop));
if (transformer)
{
m.Statements.Add(nodeStack.InvokeMethod("Push", prop));
}
m.Statements.Add(prop.InvokeMethod("AcceptVisitor",
Easy.This,
Easy.Var("data")));
if (transformer)
{
m.Body.Assign(prop, nodeStack.InvokeMethod("Pop").CastTo(ConvertType(field.FieldType)));
}
return(true);
}
static void AddFieldVisitCode(EasyMethod m, Type type, EasyExpression var, List <CodeStatement> assertions, bool transformer)
{
if (type != null)
{
if (type.BaseType != typeof(StatementWithEmbeddedStatement))
{
AddFieldVisitCode(m, type.BaseType, var, assertions, transformer);
}
foreach (FieldInfo field in type.GetFields(BindingFlags.Instance | BindingFlags.NonPublic))
{
AddVisitCode(m, field, var, assertions, transformer);
}
if (type.BaseType == typeof(StatementWithEmbeddedStatement))
{
AddFieldVisitCode(m, type.BaseType, var, assertions, transformer);
}
}
}
static CodeTypeDeclaration CreateAstVisitorClass(List <Type> nodeTypes, bool transformer)
{
EasyTypeDeclaration td = new EasyTypeDeclaration(transformer ? "AbstractAstTransformer" : "AbstractAstVisitor");
td.TypeAttributes = TypeAttributes.Public | TypeAttributes.Abstract;
td.BaseTypes.Add(new CodeTypeReference("IAstVisitor"));
if (transformer)
{
string comment =
"The AbstractAstTransformer will iterate through the whole AST,\n " +
"just like the AbstractAstVisitor. However, the AbstractAstTransformer allows\n " +
"you to modify the AST at the same time: It does not use 'foreach' internally,\n " +
"so you can add members to collections of parents of the current node (but\n " +
"you cannot insert or delete items as that will make the index used invalid).\n " +
"You can use the methods ReplaceCurrentNode and RemoveCurrentNode to replace\n " +
"or remove the current node, totally independent from the type of the parent node.";
Easy.AddSummary(td, comment);
EasyField field = td.AddField(Easy.TypeRef("Stack", "INode"), "nodeStack");
field.InitExpression = Easy.New(field.Type);
/*
* CodeExpression nodeStack = Easy.Var("nodeStack");
* CodeMemberProperty p = new CodeMemberProperty();
* p.Name = "CurrentNode";
* p.Type = new CodeTypeReference("INode");
* p.Attributes = MemberAttributes.Public | MemberAttributes.Final;
* p.GetStatements.Add(new CodeMethodReturnStatement(new CodeVariableReferenceExpression("currentNode")));
* p.SetStatements.Add(new CodeAssignStatement(new CodeVariableReferenceExpression("currentNode"),
* new CodePropertySetValueReferenceExpression()));
* td.Members.Add(p);
*/
EasyMethod m = td.AddMethod("ReplaceCurrentNode");
m.AddParameter(Easy.TypeRef("INode"), "newNode");
m.Statements.Add(Easy.Var("nodeStack").InvokeMethod("Pop"));
m.Statements.Add(Easy.Var("nodeStack").InvokeMethod("Push", Easy.Var("newNode")));
m = td.AddMethod("RemoveCurrentNode");
m.Statements.Add(Easy.Var("nodeStack").InvokeMethod("Pop"));
m.Statements.Add(Easy.Var("nodeStack").InvokeMethod("Push", Easy.Null));
}
foreach (Type type in nodeTypes)
{
if (!type.IsAbstract)
{
EasyMethod m = td.AddMethod(typeof(object), VisitPrefix + type.Name);
m.Attributes = MemberAttributes.Public;
m.AddParameter(ConvertType(type), GetFieldName(type.Name));
m.AddParameter(typeof(object), "data");
List <CodeStatement> assertions = new List <CodeStatement>();
string varVariableName = GetFieldName(type.Name);
EasyExpression var = Easy.Var(varVariableName);
assertions.Add(AssertIsNotNull(var));
AddFieldVisitCode(m, type, var, assertions, transformer);
if (type.GetCustomAttributes(typeof(HasChildrenAttribute), true).Length > 0)
{
if (transformer)
{
m.Statements.Add(new CodeSnippetStatement(CreateTransformerLoop(varVariableName + ".Children", "INode")));
m.Body.Return(Easy.Null);
}
else
{
m.Body.Return(var.InvokeMethod("AcceptChildren", Easy.This, Easy.Var("data")));
}
}
else
{
CodeExpressionStatement lastStatement = null;
if (m.Statements.Count > 0)
{
lastStatement = m.Statements[m.Statements.Count - 1] as CodeExpressionStatement;
}
if (lastStatement != null)
{
m.Statements.RemoveAt(m.Statements.Count - 1);
m.Body.Return(lastStatement.Expression);
}
else
{
m.Body.Return(Easy.Null);
}
}
for (int i = 0; i < assertions.Count; i++)
{
m.Statements.Insert(i, assertions[i]);
}
}
}
return(td);
}
