private string wrapStartProductions(string startSymbol, Dictionary <string, List <ProductionInfo> > productionsDict)
{
string new_start = grammar.RegisterNewSymbol("__start_" + startSymbol, grammar.GetTypeNameOfSymbol(startSymbol));
var prod = new ProductionInfo(SymbolPosition.None,
new_start,
RecursiveEnum.No,
new[] { new RhsSymbol(SymbolPosition.None, null, startSymbol) },
null);
var param = FuncParameter.Create(startSymbol, grammar.TreeNodeName, dummy: false);
// this code is really an identity call
prod.ActionCode = CodeLambda.CreateProxy(new_start,
// parameters
new FuncParameter[] { param },
grammar.TreeNodeName,
functionsRegistry.Add(FunctionRegistry.IdentityFunction(new_start)),
// its arguments
new [] { param.NameAsCode() });
productionsDict.Add(new_start, new List <ProductionInfo> {
prod
});
return(new_start);
}
private string registerLambda(string lhsSymbol,
IEnumerable <string> inputTypeNames,
string outputTypeName,
// each pair holds real name (like "expr") and (as backup) dummy name, like "_2"
IEnumerable <Tuple <string, string> > arguments,
CodeBody body)
{
if (inputTypeNames.Count() != arguments.Count())
{
throw new ArgumentException("Creating a function -- types count vs. arguments count mismatch.");
}
CodeLambda lambda = null;
// identity function, i.e. f(x) = x, we check only real name, if it was a dummy name, it would be
if (arguments.Count() == 1)
{
if (arguments.Single().Item1 == body.Make().Trim())
{
lambda = FunctionRegistry.IdentityFunction(lhsSymbol);
}
else if (arguments.Single().Item2 == body.Make().Trim())
{
throw new InvalidOperationException("Somehow dummy name which should not exist was referenced.");
}
}
if (lambda == null)
{
lambda = new CodeLambda(lhsSymbol, arguments.SyncZip(inputTypeNames)
.Select(it => FuncParameter.Create(it.Item1.Item1, it.Item1.Item2, it.Item2)),
outputTypeName,
body);
}
return(functionsRegistry.Add(lambda));
}
public static CodeLambda IdentityFunction(string lhs)
{
// we are creating effectivelly singleton identity function, not 100% though, because
// in case of struct instances it would lead to boxing/unboxing, BUT... TREE_NODE in NLT has to be "class"
return(new CodeLambda(lhs, new[] { FuncParameter.Create("x", "object", dummy: false) }, "object", new CodeBody().AddIdentifier("x")));
}
private ProductionInfo makeBuilderCall(string lhsSymbol,
RecursiveEnum recursive,
AltRule alt,
IEnumerable <SymbolMarked> symbolsMarked,
string treeNodeName)
{
// add production with no code
var prod_info = new ProductionInfo(alt.Position, lhsSymbol, recursive, symbolsMarked.Where(it => it.IsEnabled).Select(it => it.Symbol),
alt.MarkWith);
CodeBody code_body = null;
if (alt.Code != null)
{
code_body = (alt.Code as CodeMix).BuildBody(symbolsMarked.Where(sym => sym.Symbol.ObjName != null)
.Select(sym => sym.Symbol.GetCodeArgumentNames().Select(it => Tuple.Create(it, sym.IsEnabled))).Flatten())
.Trim();
string identity_function_on = null;
// are we just passing one of the parameters?
if (code_body.IsIdentity)
{
identity_function_on = code_body.IdentityIdentifier;
}
foreach (string var_name in code_body.GetVariables())
{
SymbolMarked sym = symbolsMarked
.Where(sm => sm.Symbol.GetCodeArgumentNames().Contains(var_name))
// there could be duplicates so we "prefer" enabled element
.OrderBy(it => it.IsEnabled ? 0 : 1)
.FirstOrDefault();
if (sym != null)
{
sym.IsParamUsed = true;
}
}
var anon_args = new Dictionary <SymbolMarked, string>();
foreach (Tuple <SymbolMarked, int> sym_pair in symbolsMarked.ZipWithIndex())
{
if (sym_pair.Item1.Symbol.ObjName == null)
{
anon_args.Add(sym_pair.Item1, code_body.RegisterNewIdentifier("_" + sym_pair.Item2));
}
}
IEnumerable <SymbolMarked> arg_symbols = symbolsMarked.Where(it => it.IsEnabled || it.IsParamUsed).ToList();
// build external function to run the user code
string func_ref = registerLambda(lhsSymbol,
arg_symbols.Select(sym => sym.Symbol.GetCodeArgumentTypes(grammar)).Flatten(),
grammar.TreeNodeName,
arg_symbols.Select(sym => sym.Symbol.GetCodeArgumentNames()
.Select(it => Tuple.Create(it, anon_args.GetOrNull(sym)))).Flatten(),
code_body);
// build a lambda with call to a just built function
// note that our lambda can have fewer arguments than the actual fuction
// in such case we pass "nulls" for disabled arguments
// we add nulls to params in order to keep track which arguments comes from which parameters
IEnumerable <FuncParameter> lambda_params = arg_symbols.Where(it => it.IsEnabled)
.Select(it => FuncParameter.Create(it.Symbol.ObjName, anon_args.GetOrNull(it), grammar.GetTypeNameOfSymbol(it.Symbol))).ToArray();
// if the code indicates that this is identity function, then just find out which parameter is passed along
if (identity_function_on != null)
{
// we can fail for two reasons here:
// (1) ok -- single variable we found in the code body is not a parameter, but global variable
// (2) BAD -- we have case of unpacking the data, and that case so far we cannot handle
// ad.2) consider such rule as
// x -> (a b)+ { b };
// "a" and "b" will be handled as tuple of lists
// so in entry function we will get a tuple, and then we will call actuall user action code
// some "__function_13__(a,b)" which returns the "b"
// so we could compute index for inner parameter (for "b" it is 1)
// but we cannot compute index for outer function, because there is no index for "b" at all
// there is only one parameter -- tuple -- holding "a" (in Item1) and "b" (in Item2) at the same time
// so if anything we would have to introduce some combo index:
// outer index --> optional unpacking index --> inner index
// too much trouble for now
Option <int> index = lambda_params.Select(it => it.Name)
.ZipWithIndex().Where(it => it.Item1 == identity_function_on).Select(it => it.Item2).OptSingle();
if (index.HasValue)
{
prod_info.IdentityOuterFunctionParamIndex = index.Value;
}
}
prod_info.ActionCode = CodeLambda.CreateProxy(
lhsSymbol,
// lambda arguments
lambda_params,
treeNodeName,
func_ref,
arg_symbols.Select(arg => arg.Symbol.CombinedSymbols == null
// regular symbols
? new[] { new CodeBody().AddIdentifier(arg.IsEnabled ? (arg.Symbol.ObjName ?? anon_args[arg]) : CodeWords.Null) }
// compound symbols, we have to use embedded atomic symbols instead now
: arg.Symbol.UnpackTuple(arg.IsEnabled)
)
.Flatten());
prod_info.CodeComment = alt.Code.Comment;
}
return(prod_info);
}
