public static bool IsConstant(Ast ast, out object constantValue, bool forAttribute = false, bool forRequires = false)
{
try
{
if ((bool)ast.Accept(new IsConstantValueVisitor { CheckingAttributeArgument = forAttribute, CheckingRequiresArgument = forRequires }))
{
Ast parent = ast.Parent;
while (parent != null)
{
if (parent is DataStatementAst)
{
break;
}
parent = parent.Parent;
}
if (parent == null)
{
constantValue = ast.Accept(new ConstantValueVisitor { AttributeArgument = forAttribute, RequiresArgument = forRequires });
return true;
}
}
}
catch (Exception e)
{
// If we get an exception, ignore it and assume the expression isn't constant.
// This can happen, e.g. if a cast is invalid:
// [int]"zed"
CommandProcessorBase.CheckForSevereException(e);
}
constantValue = null;
return false;
}
public static string ToString(Ast ast)
{
var printer = new PrettyPrinter();
ast.Accept(printer);
return(printer.ToString());
}
public void TestObjectify()
{
Parser p = new Parser();
byte[] ser = File.ReadAllBytes("testserpent.utf8.bin");
Ast ast = p.Parse(ser);
var visitor = new ObjectifyVisitor();
ast.Accept(visitor);
object thing = visitor.GetObject();
IDictionary dict = (IDictionary)thing;
Assert.AreEqual(11, dict.Count);
IList <object> list = dict["numbers"] as IList <object>;
Assert.AreEqual(4, list.Count);
Assert.AreEqual(999.1234, list[1]);
Assert.AreEqual(new ComplexNumber(-3, 8), list[3]);
string euro = dict["unicode"] as string;
Assert.AreEqual("\u20ac", euro);
IDictionary exc = (IDictionary)dict["exc"];
object[] args = (object[])exc["args"];
Assert.AreEqual("fault", args[0]);
Assert.AreEqual("ZeroDivisionError", exc["__class__"]);
}
public void TestObjectifyDictToClass()
{
Parser p = new Parser();
byte[] ser = File.ReadAllBytes("testserpent.utf8.bin");
Ast ast = p.Parse(ser);
var visitor = new ObjectifyVisitor(ZerodivisionFromDict);
ast.Accept(visitor);
object thing = visitor.GetObject();
IDictionary dict = (IDictionary)thing;
Assert.AreEqual(11, dict.Count);
DivideByZeroException ex = (DivideByZeroException)dict["exc"];
Assert.AreEqual("fault", ex.Message);
thing = ast.GetData(ZerodivisionFromDict);
dict = (IDictionary)thing;
Assert.AreEqual(11, dict.Count);
ex = (DivideByZeroException)dict["exc"];
Assert.AreEqual("fault", ex.Message);
}
internal bool IsAstSafe(Ast ast)
{
if ((bool)ast.Accept(this) && _visitCount < MaxVisitCount)
{
return(true);
}
return(false);
}
public static bool IsAstSafe(Ast ast, GetSafeValueVisitor.SafeValueContext safeValueContext)
{
IsSafeValueVisitor visitor = new IsSafeValueVisitor(safeValueContext);
if ((bool)ast.Accept(visitor) && visitor._visitCount < MaxVisitCount)
{
return true;
}
return false;
}
public void TestComments()
{
Parser p = new Parser();
Ast ast = p.Parse("[ 1, 2 ]"); // no header whatsoever
var visitor = new ObjectifyVisitor();
ast.Accept(visitor);
Object obj = visitor.GetObject();
Assert.AreEqual(new int[] { 1, 2 }, obj);
ast = p.Parse(@"# serpent utf-8 python2.7
[ 1, 2,
# some comments here
3, 4] # more here
# and here.
");
visitor = new ObjectifyVisitor();
ast.Accept(visitor);
obj = visitor.GetObject();
Assert.AreEqual(new int[] { 1, 2, 3, 4 }, obj);
}
public static bool IsConstant(Ast ast, out object constantValue, bool forAttribute = false, bool forRequires = false)
{
try
{
IsConstantValueVisitor visitor2 = new IsConstantValueVisitor {
CheckingAttributeArgument = forAttribute,
CheckingRequiresArgument = forRequires
};
if ((bool) ast.Accept(visitor2))
{
Ast parent = ast.Parent;
while (parent != null)
{
if (parent is DataStatementAst)
{
break;
}
parent = parent.Parent;
}
if (parent == null)
{
ConstantValueVisitor visitor = new ConstantValueVisitor {
AttributeArgument = forAttribute,
RequiresArgument = forRequires
};
constantValue = ast.Accept(visitor);
return true;
}
}
}
catch (Exception exception)
{
CommandProcessorBase.CheckForSevereException(exception);
}
constantValue = null;
return false;
}
public static object GetSafeValue(Ast ast, ExecutionContext context, SafeValueContext safeValueContext)
{
s_context = context;
if (IsSafeValueVisitor.IsAstSafe(ast, safeValueContext))
{
return(ast.Accept(new GetSafeValueVisitor()));
}
if (safeValueContext == SafeValueContext.ModuleAnalysis)
{
return(null);
}
throw PSTraceSource.NewArgumentException("ast");
}
private static object CompileAndInvoke(Ast ast)
{
object obj2;
try
{
Compiler visitor = new Compiler {
CompilingConstantExpression = true
};
obj2 = Expression.Lambda((Expression) ast.Accept(visitor), new ParameterExpression[0]).Compile().DynamicInvoke(new object[0]);
}
catch (TargetInvocationException exception)
{
throw exception.InnerException;
}
return obj2;
}
public CompileResult Compile(Ast ast)
{
Reset();
ast.Accept(this);
//chunk.WriteOpCode(OpCode.RETURN);
//chunk.WriteOpCode(OpCode.CONSTANT);
//chunk.WriteWord(chunk.AddConstant(new Value(1)));
//chunk.WriteOpCode(OpCode.NEGATE);
//chunk.WriteOpCode(OpCode.CONSTANT);
//chunk.WriteWord(chunk.AddConstant(new Value(123)));
//chunk.WriteOpCode(OpCode.DIV);
//chunk.WriteOpCode(OpCode.CONSTANT);
//chunk.WriteWord(chunk.AddConstant(new Value(1)));
//chunk.WriteOpCode(OpCode.ADD);
//chunk.WriteOpCode(OpCode.CONSTANT);
//chunk.WriteWord(chunk.AddConstant(new Value(0.1)));
//chunk.WriteOpCode(OpCode.DIV);
//ChunkDebug.Dump("Chunk Dump:", chunk);
return(new CompileResult(success, chunk, errors));
}
public void ExampleUsage()
{
Console.WriteLine("using serpent library version {0}", LibraryVersion.Version);
var data = new Dictionary <string, object> {
{ "tuple", new [] { 1, 2, 3 } },
{ "date", DateTime.Now },
{ "set", new HashSet <string> {
"a", "b", "c"
} },
{ "class", new SampleClass
{
Name = "Sally",
Age = 26
} }
};
// serialize data structure to bytes
Serializer serpent = new Serializer(true);
var ser = serpent.Serialize(data);
// print it on the screen, but normally you'd store byte bytes in a file or transfer them across a network connection
Console.WriteLine("Serialized:");
Console.WriteLine(Encoding.UTF8.GetString(ser));
// parse the serialized bytes back into an abstract syntax tree of the datastructure
Parser parser = new Parser();
Ast ast = parser.Parse(ser);
Console.WriteLine("\nParsed AST:");
Console.WriteLine(ast.Root.ToString());
// print debug representation
DebugVisitor dv = new DebugVisitor();
ast.Accept(dv);
Console.WriteLine("DEBUG string representation:");
Console.WriteLine(dv.ToString());
// turn the Ast into regular .net objects
var dict = (IDictionary)ast.GetData();
// You can get the data out of the Ast manually as well, by using the supplied visitor:
// var visitor = new ObjectifyVisitor();
// ast.Accept(visitor);
// var dict = (IDictionary) visitor.GetObject();
// print the results
Console.WriteLine("PARSED results:");
Console.Write("tuple items: ");
var tuple = (object[])dict["tuple"];
Console.WriteLine(string.Join(", ", tuple.Select(e => e.ToString()).ToArray()));
Console.WriteLine("date: {0}", dict["date"]);
Console.Write("set items: ");
var set = (HashSet <object>)dict["set"];
Console.WriteLine(string.Join(", ", set.Select(e => e.ToString()).ToArray()));
Console.WriteLine("class attributes:");
var clazz = (IDictionary)dict["class"]; // custom classes are serialized as dicts
Console.WriteLine(" type: {0}", clazz["__class__"]);
Console.WriteLine(" name: {0}", clazz["name"]);
Console.WriteLine(" age: {0}", clazz["age"]);
Console.WriteLine("");
// parse and print the example file
ser = File.ReadAllBytes("testserpent.utf8.bin");
ast = parser.Parse(ser);
dv = new DebugVisitor();
ast.Accept(dv);
Console.WriteLine("DEBUG string representation of the test file:");
Console.WriteLine(dv.ToString());
}
public void PostVisit(Ast ast)
{
ast.Accept(_symbolResolvePostActionVisitor);
}
private void GenerateWhileLoop(string loopLabel, Action generateCondition, Action generateLoopBody, Ast continueAction = null)
{
Block next = new Block();
if (continueAction != null)
{
Block block2 = new Block();
this._currentBlock.FlowsTo(block2);
this._currentBlock = next;
continueAction.Accept(this);
this._currentBlock.FlowsTo(block2);
this._currentBlock = block2;
}
else
{
this._currentBlock.FlowsTo(next);
this._currentBlock = next;
}
Block block3 = new Block();
Block block4 = new Block();
if (generateCondition != null)
{
generateCondition();
this._currentBlock.FlowsTo(block4);
}
this._loopTargets.Add(new LoopGotoTargets(loopLabel ?? "", block4, next));
this._currentBlock.FlowsTo(block3);
this._currentBlock = block3;
generateLoopBody();
this._currentBlock.FlowsTo(next);
this._currentBlock = block4;
this._loopTargets.RemoveAt(this._loopTargets.Count - 1);
}
private bool IsValidAttributeArgument(Ast ast, IsConstantValueVisitor visitor)
{
return (bool)ast.Accept(visitor);
}
internal Expression Compile(Ast ast)
{
return (Expression)ast.Accept(this);
}
public void Print()
{
Ast.Accept(this);
}
public static object GetSafeValue(Ast ast, ExecutionContext context, SafeValueContext safeValueContext)
{
s_context = context;
if (IsSafeValueVisitor.IsAstSafe(ast, safeValueContext))
{
return ast.Accept(new GetSafeValueVisitor());
}
if (safeValueContext == SafeValueContext.ModuleAnalysis)
{
return null;
}
throw PSTraceSource.NewArgumentException("ast");
}
private static object CompileAndInvoke(Ast ast)
{
try
{
var compiler = new Compiler { CompilingConstantExpression = true };
return Expression.Lambda((Expression)ast.Accept(compiler)).Compile().DynamicInvoke();
}
catch (TargetInvocationException tie)
{
throw tie.InnerException;
}
}
private void CheckIsConstant(Ast ast, string msg)
{
Diagnostics.Assert(
(bool)ast.Accept(new IsConstantValueVisitor { CheckingAttributeArgument = this.AttributeArgument, CheckingRequiresArgument = RequiresArgument }), msg);
}
private bool IsValidAttributeArgument(Ast ast)
{
var obj = ast.Accept(this._isConstantValueVisitor);
if (obj is bool) return (bool)obj;
return false;
}
private void GenerateWhileLoop(string loopLabel,
Action generateCondition,
Action generateLoopBody,
Ast continueAction = null)
{
// We model the flow graph like this (if continueAction is null, the first part is slightly different):
// goto L
// :ContinueTarget
// continueAction
// :L
// if (condition)
// {
// loop body
// // break -> goto BreakTarget
// // continue -> goto ContinueTarget
// goto ContinueTarget
// }
// :BreakTarget
var continueBlock = new Block();
if (continueAction != null)
{
var blockAfterContinue = new Block();
// Represent the goto over the condition before the first iteration.
_currentBlock.FlowsTo(blockAfterContinue);
_currentBlock = continueBlock;
continueAction.Accept(this);
_currentBlock.FlowsTo(blockAfterContinue);
_currentBlock = blockAfterContinue;
}
else
{
_currentBlock.FlowsTo(continueBlock);
_currentBlock = continueBlock;
}
var bodyBlock = new Block();
var breakBlock = new Block();
// Condition can be null from an uncommon for loop: for() {}
if (generateCondition != null)
{
generateCondition();
_currentBlock.FlowsTo(breakBlock);
}
_loopTargets.Add(new LoopGotoTargets(loopLabel ?? "", breakBlock, continueBlock));
_currentBlock.FlowsTo(bodyBlock);
_currentBlock = bodyBlock;
generateLoopBody();
_currentBlock.FlowsTo(continueBlock);
_currentBlock = breakBlock;
_loopTargets.RemoveAt(_loopTargets.Count - 1);
}
public Tacs Generate(Ast ast)
{
ast.Accept(this);
return(tacs);
}
