internal override Value Eval(DelimiterNode prev, DelimiterNode next, IScope paramScope, IScope bodyScope, INodeRequestor nodes, ILineRequestor requestor)
{
// if we need prev or next params but they're not there, simply return the function
if ((m_usePrevious || m_useNext) && prev == null && next == null)
return this;
// scope we'll add prev/next/body params to
ScopeChain localScope = new ScopeChain();
if (m_usePrevious)
{
if (prev == null)
{
if (m_useNext)
return new PartialFunctionIn(this, null, next);
throw new Loki3Exception().AddMissingValue(true/*bPrevious*/);
}
Value value1 = ComputeParam(Metadata[keyPreviousPattern], prev, paramScope, nodes, requestor);
Value match, leftover;
if (!PatternChecker.Do(value1, Metadata[keyPreviousPattern], false/*bShortPat*/, out match, out leftover))
throw new Loki3Exception().AddWrongPattern(Metadata[keyPreviousPattern], value1);
if (leftover != null)
{
if (m_useNext)
// currently can't do partials for infix
throw new Loki3Exception().AddWrongPattern(Metadata[keyPreviousPattern], value1);
// create a partial function that starts w/ match & still needs leftover
return new UserFunction(this, match, leftover, null);
}
Utility.AddToScope(m_pattern1, match, localScope);
}
if (m_useNext)
{
if (next == null)
{
if (m_usePrevious)
return new PartialFunctionIn(this, prev, null);
throw new Loki3Exception().AddMissingValue(false/*bPrevious*/);
}
Value value2 = ComputeParam(Metadata[keyNextPattern], next, paramScope, nodes, requestor);
Value match, leftover;
if (!PatternChecker.Do(value2, Metadata[keyNextPattern], false/*bShortPat*/, out match, out leftover))
throw new Loki3Exception().AddWrongPattern(Metadata[keyNextPattern], value2);
// if we created a function that needs a body, add it if present
ValueFunction matchFunc = match as ValueFunction;
if (matchFunc != null && matchFunc.RequiresBody() && requestor != null)
match = EvalList.DoAddBody(matchFunc, bodyScope, requestor);
if (leftover != null)
{
if (m_usePrevious)
// currently can't do partials for infix
throw new Loki3Exception().AddWrongPattern(Metadata[keyNextPattern], value2);
// create a partial function that starts w/ match & still needs leftover
return new UserFunction(this, match, null, leftover);
}
Utility.AddToScope(m_pattern2, match, localScope);
}
// tack on body if requested
if (Metadata.GetOptionalT<bool>("body?", false))
{
bool foundBody = false;
// if there's a following node, use it
DelimiterNode possibleBody = nodes.GetNext();
if (possibleBody != null)
{
localScope.SetValue("body", UseNodeAsBody(possibleBody));
foundBody = true;
}
// if no body, use the following lines
if (!foundBody && requestor != null)
{
List<DelimiterList> body = EvalList.DoGetBody(bodyScope, requestor);
if (body.Count != 0)
{
localScope.SetValue("body", new ValueLine(body, bodyScope));
foundBody = true;
}
}
if (!foundBody)
// create a partial function that only needs a body
return new UserFunction(this, localScope);
}
// create a new scope and add passed in arguments...
ScopeChain scope = (ShouldCreateScope ? new ScopeChain(bodyScope) : bodyScope as ScopeChain);
scope.Function = this;
if (m_fullPattern != null && m_passed != null)
Utility.AddToScope(m_fullPattern, m_passed, scope);
// ...and the prev/next/body params we just extracted
Utility.AddToScope(localScope, scope);
if (m_passedScope != null)
Utility.AddToScope(m_passedScope, scope);
// lazily parse
EnsureParsed(bodyScope);
// eval each line using current scope
try
{
Value retval = EvalBody.Do(m_parsedLines, scope);
scope.Exit();
return retval;
}
catch (PopStackException pop)
{ // if we're supposed to pop back to here then return, else keep throwing up the stack
if (pop.ScopeName == scope.Name)
return pop.Return;
throw pop;
}
catch (Loki3Exception e)
{ // if this scope catches exceptions, stop here
if (Loki3Exception.catchScopeName == scope.Name)
{
if (scope.Parent != null)
scope.Parent.SetValue(Loki3Exception.exceptionKey, new ValueMap(e.Errors));
return ValueNil.Nil;
}
throw e;
}
}
/// <summary>
/// Evaluates a token, possibly requesting the previous and next values.
/// Returns a value.
/// </summary>
/// <param name="token">token representing a function or variable</param>
/// <param name="scope">used to request functions, variables, and delimiters if there's no scope attached to the node</param>
/// <param name="nodes">used to request previous and next nodes</param>
internal static Value Do(DelimiterNode node, IScope scope, INodeRequestor nodes, ILineRequestor requestor)
{
if (node.Value != null)
{ // node has already been evaluated
return node.Value;
}
else if (node.Token != null)
{ // function/variable or built-in
Token token = node.Token;
Value value = scope.GetValue(token);
if (value is ValueFunction && nodes != null)
{
ValueFunction function = value as ValueFunction;
// get previous & next nodes if needed
DelimiterNode previous = (function.ConsumesPrevious ? nodes.GetPrevious() : null);
DelimiterNode next = (function.ConsumesNext ? nodes.GetNext() : null);
scope.FunctionName = token.Value;
// evaluate
try
{
return function.Eval(previous, next, scope, scope, nodes, requestor);
}
catch (Loki3Exception e)
{ // this function is the correct context if there isn't already one there
if (!e.Errors.ContainsKey(Loki3Exception.keyFunction))
e.AddFunction(token.Value);
if (!e.Errors.ContainsKey(Loki3Exception.keyScope))
e.AddScope(scope);
throw e;
}
}
else if (value != null)
{
return value;
}
else
{
return EvalBuiltin.Do(token);
}
}
else if (node.List != null)
{ // delimited list of nodes
Value value = null;
DelimiterList list = node.List;
IScope listScope = (list.Scope != null ? list.Scope : scope);
DelimiterType type = list.Delimiter.DelimiterType;
// get contents as a Value
switch (type)
{
case DelimiterType.AsString:
value = new ValueString(list.Original);
break;
case DelimiterType.AsValue:
value = EvalList.Do(list.Nodes, listScope);
break;
case DelimiterType.AsArray:
List<Value> values = new List<Value>(list.Nodes.Count);
foreach (DelimiterNode subnode in list.Nodes)
{ // note: 'nodes' is null so functions don't get evaled
Value subvalue = Do(subnode, listScope, null, requestor);
values.Add(subvalue);
}
value = new ValueArray(values);
break;
case DelimiterType.AsEvaledArray:
value = EvalList.DoEvaledArray(list.Nodes, listScope);
break;
case DelimiterType.AsRaw:
value = new ValueRaw(list, listScope);
break;
case DelimiterType.AsArrayOfRaw:
List<Value> rawvalues = new List<Value>(list.Nodes.Count);
foreach (DelimiterNode subnode in list.Nodes)
rawvalues.Add(new ValueRaw(subnode, listScope));
value = new ValueArray(rawvalues);
break;
}
// run contents through a function if specified
ValueFunction function = list.Delimiter.Function;
if (function == null)
return value;
DelimiterNode next = new DelimiterNodeValue(value);
return function.Eval(null, next, scope, scope, nodes, requestor);
}
return new ValueNil();
}
/// <summary>Evaluate this node, possibly consuming adjacent nodes</summary>
internal void Eval(IScope scope, INodeRequestor nodes, ILineRequestor requestor)
{
if (m_state != NodeState.Node && m_state != NodeState.Function)
return;
// get new value
if (m_state == NodeState.Node)
{ // hasn't been evaled at all
m_value = EvalNode.Do(m_node, scope, nodes, requestor);
}
else if (m_state == NodeState.Function)
{ // previously resolved to a function
DelimiterNode previous = (m_func.ConsumesPrevious ? previous = nodes.GetPrevious() : null);
DelimiterNode next = (m_func.ConsumesNext ? next = nodes.GetNext() : null);
if ((m_func.ConsumesPrevious || m_func.ConsumesNext) && (previous == null && next == null))
{ // no prev/next parameters passed, perhaps it can use body?
if (m_func.RequiresBody() && requestor != null)
{ // tack on body if present
m_value = EvalList.DoAddBody(m_func, scope, requestor);
}
else
{ // function can't be evaled further
m_state = NodeState.Value;
return;
}
}
else
{
if (!m_func.ConsumesPrevious && !m_func.ConsumesNext && !m_func.RequiresBody() && !m_func.ForceEval)
{ // function can't be evaled further
m_state = NodeState.Value;
return;
}
m_value = m_func.Eval(previous, next, scope, scope, nodes, requestor);
}
}
if (m_value == null)
{ // e.g. because node was a comment
m_state = NodeState.Empty;
return;
}
// store new info about this node
m_node = new DelimiterNodeValue(m_value);
m_order = (int)m_value.Order;
if (m_value.Type == ValueType.Function)
{
m_state = NodeState.Function;
m_func = m_value as ValueFunction;
}
else
{
m_state = NodeState.Value;
}
}