public override void run( State state )
{
// We execute here by simply "running" each of the steps and letting them
// push onto the stack. There is no branching possible, and these calls will
// be shallow / non-blocking, so there's no need to do anything tricky or conditional.
//
// One point of interest is that we push a "clear results" step after each statement
// just to verify that nothing was left on the results stack (this happens and is okay).
foreach( AstNode c in ((IEnumerable<AstNode>)_children).Reverse() )
{
// Clear the result stack after each statement.
state.pushAction( new Step( this, st2 => st2.clearResults(), "[Clear Results]" ) );
c.run( state );
};
}
public override void run( State state )
{
// We execute by executing the "lhs" and "rhs" code, then using the lhs's
// LValue callbacks to set the value.
state.pushAction(
new Step( this, s =>
{
LValue lv = (LValue)s.popResult();
object rv = LValue.Deref( s );
lv.write( s, rv );
} )
);
this.lhs.run( state );
this.rhs.run( state );
}
public override void run( State state )
{
// We execute here by searching up the stack for the previous function call
// scope marker, and unwinding past that, then pushing on our return value.
state.pushAction( new Step( this, st =>
{
st.pushAction( new Step( this, st2 =>
{
// Make sure we don't leak LValues.
st2.pushResult( LValue.Deref( st2 ) );
// And do the stack unwind.
st2.unwindActions( step => AstCall.IsScopeMarker( step ) );
}, "return: stack unwinder" ) );
if( this.value != null )
this.value.run( st );
else
st.pushResult( null );
} ) );
}
public override void run( State state )
{
// We execute here by executing the condition, then interpreting the
// outcome of that expression to determin if we should push on the contents
// of the block.
//
// In order to handle multiple elif clauses, we curry a "clause index" value
// in the continuations so that it can chain to the next elif or else if
// the condition isn't true.
state.pushAction( new Step( this, st => ifRunner( st, 0 ), this.clauses[0].ToString() ) );
this.clauses[0].condition.run( state );
}
// Pulls the result of a conditional comparison and either queues the attached
// block, or queues the next comparison.
void ifRunner( State st, int clauseIndex )
{
object result = LValue.Deref( st );
bool conv = Util.CoerceBool( result );
if( conv )
this.clauses[clauseIndex].block.run( st );
else
{
++clauseIndex;
if( clauseIndex >= this.clauses.Length )
return;
if( this.clauses[clauseIndex].condition == null )
{
this.clauses[clauseIndex].block.run( st );
}
else
{
st.pushAction( new Step( this, st2 => ifRunner( st2, clauseIndex ), this.clauses[clauseIndex].ToString() ) );
this.clauses[clauseIndex].condition.run( st );
}
}
}
// This IEnumerable implementation will be very inefficient for large arrays.
void oneIteration( State state )
{
state.pushAction( new Step( this, st =>
{
object resultObj = LValue.Deref( st );
bool result = Util.CoerceBool( resultObj );
if( result )
{
st.pushAction( new Step( this, st2 =>
{
oneIteration( st2 );
}, "while: next block runner" ) );
if( this.postLoop != null )
this.postLoop.run( st );
st.pushAction( new Step( this, a => {}, BlockMarker ) );
this.block.run( st );
}
}, "while: test checker" ) );
this.test.run( state );
}
public override void run( State state )
{
// We execute by first evaluating the test, and then if that's true, pushing one
// iteration of the loop onto the action stack. Each iteration, if it completes
// successfully, will push the next on. We also push a while loop marker on so
// that break and continue work.
state.pushAction( new Step( this, a => {}, LoopMarker ) );
oneIteration( state );
if( this.preLoop != null )
this.preLoop.run( state );
}
public override void run( State state )
{
// We execute by pushing all the code for building the keys and values onto the
// action stack, and finish off with one that will combine them all.
state.pushAction(
new Step( this, s =>
{
var dict = new Dictionary<object, object>();
for( int i=0; i<this.pairs.Count; ++i )
{
object key = LValue.Deref( s );
object value = LValue.Deref( s );
dict[key] = value;
}
s.pushResult( dict );
} )
);
foreach( Pair p in this.pairs )
{
p.key.run( state );
p.value.run( state );
}
}
public override void run( State state )
{
// We execute by pushing on a stack unwind marker step, then executing our
// try block. If nothing happens, the unwind marker will execute any finally block.
// If an exception is thrown, then we'll unwind the stack until we hit the stack
// marker, then execute any except block. We'll then execute any finally block.
//
// Because exceptions can happen deep in the stack and/or from random sources,
// we provide a throwException method to take care of the dirty work.
state.pushAction( new Step( this, a =>
{
if( this.finallyBlock != null )
this.finallyBlock.run( state );
},
TryMarker )
);
this.tryBlock.run( state );
}
public override void run( State state )
{
// How we execute depends on whether we're a lambda or not. In the lambda case, we
// just push an FValue on the result stack and call it done. For the non-lambda case,
// we create a variable in the scope with an FValue in it. In either case, there's not
// much actual executing being done here.
FValue fv = new FValue( this );
fv.scope = state.scope;
if( this.lambda )
{
state.pushAction( new Step( this, st => st.pushResult( fv ) ) );
}
else
{
state.pushAction( new Step( this, st => st.scope.set( this.name, fv ) ) );
}
}
// This IEnumerable implementation will be very inefficient for large arrays.
void oneIteration( State state, IEnumerable<object> array, int curIndex )
{
if( curIndex < array.Count() - 1 )
{
state.pushAction( new Step( this,
st =>
{
oneIteration( st, array, curIndex + 1 );
},
NextIterationMarker )
);
}
else
{
// This is still needed to make continue work.
state.pushAction( new Step( this, st => {}, NextIterationMarker ) );
}
this.block.run( state );
state.pushAction( new Step( this,
st =>
{
st.scope.set( this.loopVariable, array.Skip( curIndex ).First() );
},
"for: assign iterator " + this.loopVariable )
);
}
public override void run( State state )
{
// We execute by first evaluating the loopOver and then pushing one iteration of
// the loop onto the action stack. Each iteration, if it completes successfully,
// will push the next on. The array and current index are curried. We also push
// a for loop marker on so that break works.
state.pushAction( new Step( this, st =>
{
object over = LValue.Deref( st );
IEnumerable<object> overTyped;
if( over is List<object> )
overTyped = (IEnumerable<object>)over;
else if( over is Dictionary<object,object> )
overTyped = ((Dictionary<object,object>)over).Keys;
else
throw CoralException.GetArg( "Value is not enumerable" );
IScope forScope = new ParameterScope( st.scope, new string[] { this.loopVariable } );
state.pushActionAndScope( new Step( this, a => {}, ScopeMarker ), forScope );
state.scope.set( this.loopVariable, null );
oneIteration( st, overTyped, 0 );
} ) );
this.loopOver.run( state );
}
public override void run( State state )
{
// We execute here by evaulating each of the parameters as well as the source, and then
// evaluating the source FValue; of course if we don't get an FValue, that's an error.
state.pushAction( new Step( this, st =>
{
// Make sure the FValue isn't an LValue.
object fvo = st.popResult();
if( fvo is FValue )
{
// Everything's okay
}
else if( fvo is LValue )
fvo = LValue.Deref( st, fvo );
else
throw CoralException.GetArg( "Attempted call to non-function" );
if( fvo == null )
throw CoralException.GetArg( "Attempted call to null function" );
FValue fv = (FValue)fvo;
// Gather arguments before we push any scopes.
var argsArray = new List<object>();
if( fv.func != null )
{
for( int i=0; i<this.parameters.Length; ++i )
{
object value = LValue.Deref( st );
argsArray.Add( value );
}
}
else
{
object[] args = this.parameters.Select( n => LValue.Deref( st ) ).ToArray();
argsArray.AddRange( args );
}
// Push on a scope marker so that the function will run in its own scope.
IScope oldScope;
if( fv.scope == null )
oldScope = st.constScope;
else
oldScope = fv.scope;
st.pushActionAndScope( new Step( this, a => {}, ScopeMarker ), new StandardScope( oldScope ) );
// The actual run action.
if( fv.func != null )
{
// Push on a pusher for a null return value. This is to ensure that calls always return
// something, for result stack sanity. This won't get executed if the function returns
// a value on its own.
st.pushAction( new Step( this, st2 => st2.pushResult( null ), "call: result pusher" ) );
// Set a second scope with just the parameters.
IScope callScope = new ParameterScope( st.scope,
fv.func.parameters.Union( new string[] { "arguments" } ).ToArray() );
st.pushActionAndScope( new Step( this, a => {}, "call: parameter scope" ), callScope );
callScope.set( "arguments", argsArray );
for( int i=0; i<argsArray.Count; ++i )
if( i < fv.func.parameters.Length )
{
string name = fv.func.parameters[i];
st.scope.set( name, argsArray[i] );
}
else
break;
// Do the actual function call.
fv.func.block.run( st );
}
else if( fv.metal != null )
{
fv.metal( st, argsArray.ToArray() );
}
else
throw CoralException.GetArg( "Attempt to call null function" );
} ) );
this.source.run( state );
foreach( AstNode p in this.parameters )
p.run( state );
}
public override void run( State state )
{
// We execute by evaulating the RValue portion first, then producing an LValue. If
// the RValue is itself an LValue, we need to deref that first.
state.pushAction( new Step( this, st =>
{
object rval = LValue.Deref( st );
if( rval is MetalObject )
{
// Metal object callbacks produce an LValue automatically.
((MetalObject)rval).memberLookup( st, this.member );
}
else
{
// We must produce an LValue ourselves, that wraps the dictionary access.
st.pushResult( new LValue()
{
read = st3 =>
{
if( rval is Dictionary<object,object> )
{
var dict = (Dictionary<object,object>)rval;
if( dict.ContainsKey( this.member ) )
return dict[this.member];
else
return null;
}
else if( rval is List<object> )
{
if( this.member == "length" )
{
return new FValue( (st4, args) =>
{
st4.pushResult( ((List<object>)rval).Count );
}
);
}
else
return null;
}
else if( rval is string )
{
return StringObject.Method( st3, (string)rval, this.member );
}
else
{
return null;
}
},
write = ( st3, val ) =>
{
if( rval is Dictionary<object,object> )
{
var dict = (Dictionary<object,object>)rval;
dict[this.member] = val;
}
else
{
throw CoralException.GetArg( "Can't access value as object for write" );
}
}
} );
}
} ) );
this.rvalue.run( state );
}
public override void run( State state )
{
// We execute by getting the indexer value and the source, looking the
// value in question up, and then pushing the result on the result stack.
state.pushAction( new Step( this, st =>
{
object source = LValue.Deref( st );
object index = LValue.Deref( st );
if( source is Dictionary<object,object> )
{
var sourcedict = (Dictionary<object,object>)source;
if( sourcedict.ContainsKey( index ) )
st.pushResult( sourcedict[index] );
else
st.pushResult( null );
}
else if( source is List<object> && index is int )
{
var sourcelist = (List<object>)source;
int indexint = (int)index;
if( indexint < sourcelist.Count )
st.pushResult( sourcelist[indexint] );
else
st.pushResult( null );
}
else if( source is string && index is int )
{
st.pushResult( StringObject.ArrayAccess( (string)source, (int)index ) );
}
else if( source is MetalObject && ((MetalObject)source).indexLookup != null )
{
((MetalObject)source).indexLookup( st, index );
}
else
{
// Whatever is left never has a value.
st.pushResult( null );
}
} ) );
this.source.run( state );
this.index.run( state );
}
/// <summary>
/// Throws an exception.
/// </summary>
/// <param name="thrown">
/// The object to throw. It's recommended that this be a dictionary with a
/// "name" parameter at the least.
/// </param>
public void throwException( State state, object thrown )
{
// We want to have stack traces, so this is necessary... but we also want to
// throw data objects and not C# objects. So we have to convert back and forth.
if( !(thrown is CoralException) )
thrown = new CoralException( thrown );
var cex = (CoralException)thrown;
if( cex.trace == null )
cex.setStackTrace( state );
thrown = cex.data;
state.pushAction( new Step( this, st =>
{
// We'll want to hold on to the finally runner if there is one. This will
// let us properly handle nested exceptions.
Step finallyStep = null;
st.unwindActions( step => IsTryMarker( step ), this.finallyBlock != null );
if( this.finallyBlock != null )
finallyStep = st.popAction();
// The except block may have a parameter.
if( this.exceptIdentifer != null )
{
IScope exceptScope = new ParameterScope( st.scope, new string[] { this.exceptIdentifer } );
exceptScope.set( this.exceptIdentifer, thrown );
state.pushActionAndScope( new Step( this, a => {}, "except: scope" ), exceptScope );
}
this.exceptBlock.run( st );
if( finallyStep != null )
{
finallyStep.description = "finally block";
st.pushAction( finallyStep );
}
},
"throw" )
);
}
/// <summary>
/// Works like throwException(), except we search for the right try clause.
/// </summary>
public static void ThrowException( State state, object thrown )
{
Step tryStep = state.findAction( step => IsTryMarker( step ) );
if( tryStep == null )
{
// Make sure we have a CoralException.
if( !(thrown is CoralException) )
thrown = new CoralException( thrown );
CoralException cex = (CoralException)thrown;
if( cex.trace == null )
cex.setStackTrace( state );
// Unwind everything else off the stack. There is an implicit "except" at the top anyway.
state.clearActions();
// Push on a thrower. We do this in a separate step so that the same try/catch can deal
// with it at the Runner level.
state.pushAction( new Step( null, a => { throw new UnhandledException( (CoralException)thrown ); }, "re-thrower" ) );
return;
}
AstTry node = (AstTry)tryStep.node;
node.throwException( state, thrown );
}
public override void run( State state )
{
// We execute by running the "lhs" and "rhs", and then applying the operator to them,
// producing another value. If the result of either is an LValue, we have to dereference it.
state.pushAction(
new Step( this, st =>
{
object right = LValue.Deref( st );
if( this.op == "+=" )
{
object left = st.popResult();
// This one is a bit trickier since we do different things based on different
// types, and the left side needs to be an LValue.
if( !(left is LValue) )
throw CoralException.GetArg( "Left-hand side of += must be LValue" );
// We need to write the LValue back, but keep the result value on
// the result stack since this can be used as a normal expression too.
LValue lv = (LValue)left;
object val = lv.read( st );
val = Plus( val, right );
lv.write( st, val );
st.pushResult( val );
}
else
{
if( this.left != null )
{
object left = LValue.Deref( st );
st.pushResult( s_operations[this.op]( left, right ) );
}
else if( this.op == "-" )
{
st.pushResult( s_operations[this.op]( null, right ) );
}
else if( this.op == "!" )
{
st.pushResult( !((bool)Util.CoerceBool( right ) ) );
}
else
throw CoralException.GetInvProg( "Unary operator not supported" );
}
} )
);
this.right.run( state );
if( this.left != null )
this.left.run( state );
else
state.pushResult( null );
}
public override void run( State state )
{
state.pushAction( new Step( this, st =>
{
object source = LValue.Deref( st );
object obegin = LValue.Deref( st );
object oend = LValue.Deref( st );
int? begin = obegin == null ? (int?)null : Util.CoerceNumber( obegin );
int? end = oend == null ? (int?)null : Util.CoerceNumber( oend );
if( source is List<object> )
{
var slist = (List<object>)source;
int ibegin, iend;
Util.ArraySlice( slist.Count, begin, end, out ibegin, out iend );
var result = new List<object>( slist.Skip( ibegin ).Take( iend - ibegin ) );
st.pushResult( result );
}
else if( source is string )
{
st.pushResult( StringObject.ArraySlice( (string)source, begin, end ) );
}
else
throw CoralException.GetArg( "Can't array slice this type" );
} ) );
// These are different enough that we just break them out.
this.source.run( state );
if( this.begin != null && this.end != null )
{
this.begin.run( state );
this.end.run( state );
}
else if( this.begin == null )
{
state.pushAction( new Step( this, st => st.pushResult( null ), "slice: null pusher" ) );
this.end.run( state );
}
else
{
this.begin.run( state );
state.pushAction( new Step( this, st => st.pushResult( null ), "slice: null pusher" ) );
}
}
