public static IEnumerator ConvertAnythingToIterator(TemplateFrame frame, object o)
{
o = ConvertAnythingIteratableToIterator(frame, o);
IEnumerator iter = o as IEnumerator;
if (iter != null)
return iter;
Template.AttributeList singleton = new Template.AttributeList(1);
singleton.Add(o);
return singleton.GetEnumerator();
}
// <names,phones:{n,p | ...}> or <a,b:t()>
// todo: i, i0 not set unless mentioned? map:{k,v | ..}?
protected virtual Template.AttributeList ZipMap(TemplateFrame frame, List<object> exprs, Template prototype)
{
Template self = frame.Template;
if (exprs == null || prototype == null || exprs.Count == 0)
{
return null; // do not apply if missing templates or empty values
}
// make everything iterable
for (int i = 0; i < exprs.Count; i++)
{
object attr = exprs[i];
if (attr != null)
exprs[i] = ConvertAnythingToIterator(frame, attr);
}
// ensure arguments line up
int numExprs = exprs.Count;
CompiledTemplate code = prototype.impl;
List<FormalArgument> formalArguments = code.FormalArguments;
if (!code.HasFormalArgs || formalArguments == null)
{
_errorManager.RuntimeError(frame, ErrorType.MISSING_FORMAL_ARGUMENTS);
return null;
}
// todo: track formal args not names for efficient filling of locals
object[] formalArgumentNames = formalArguments.Select(i => i.Name).ToArray();
int nformalArgs = formalArgumentNames.Length;
if (prototype.IsAnonymousSubtemplate)
nformalArgs -= predefinedAnonSubtemplateAttributes.Length;
if (nformalArgs != numExprs)
{
_errorManager.RuntimeError(frame, ErrorType.MAP_ARGUMENT_COUNT_MISMATCH, numExprs, nformalArgs);
// TODO just fill first n
// truncate arg list to match smaller size
int shorterSize = Math.Min(formalArgumentNames.Length, numExprs);
numExprs = shorterSize;
Array.Resize(ref formalArgumentNames, shorterSize);
}
// keep walking while at least one attribute has values
Template.AttributeList results = new Template.AttributeList();
int i2 = 0; // iteration number from 0
while (true)
{
// get a value for each attribute in list; put into Template instance
int numEmpty = 0;
Template embedded = group.CreateStringTemplateInternally(prototype);
embedded.RawSetAttribute("i0", i2);
embedded.RawSetAttribute("i", i2 + 1);
for (int a = 0; a < numExprs; a++)
{
IEnumerator it = (IEnumerator)exprs[a];
if (it != null && it.MoveNext())
{
string argName = (string)formalArgumentNames[a];
object iteratedValue = it.Current;
embedded.RawSetAttribute(argName, iteratedValue);
}
else
{
numEmpty++;
}
}
if (numEmpty == numExprs)
break;
results.Add(embedded);
i2++;
}
return results;
}