doesnt work yet

AHHHHH.d

#!opend -mixin=mix -unittest -main -run app.d
import std;
auto toiter(R)(/*ref*/R r) if (isInputRange!R){
	return (int delegate(ref ElementType!R) dg){
		int ret;
		while( ! r.empty){
			ret=dg(r.front);
			r.popFront;
			if(ret){return ret;}
		}
		return ret;
	};
}
auto toiter(T)(ref T t) if ( ! isInputRange!T){
	return (int delegate(ref T) dg){
		return dg(t);
	};
}
template myelementtype(T){
	static if(istuple!T){
		static if(isInputRange!(T.type!0)){
			alias myelementtype=ElementType!(T.type!0);
		} else {
			alias myelementtype=T.type!0;
		}
	} else {
		static if(isInputRange!T){
			alias myelementtype=ElementType!T;
		} else {
			alias myelementtype=T;
}}}
unittest{
	//myelementtype!int.stringof.writeln;
	//myelementtype!(int[]).stringof.writeln;
	//myelementtype!(Tuple!(int[],int)).stringof.writeln;
	//myelementtype!(Tuple!(int,int[])).stringof.writeln;
	//myelementtype!(Tuple!(int,int[])).stringof.writeln;
}
string ndfieldheader(string order,T...)(){
	string output="(int delegate(";
	string[T.length] types;
	static foreach(I,c;order[0..T.length]){
		types[getndindex(c)]=/*"ref*/"myelementtype!(T["~I.to!string~"])";
	}
	foreach(int i,s;types){
		output~="ref ";
		output~=s;
		output~=" ";
		output~=getndchar(i);
		output~=",";
	}
	output~="ref typeof(F(";
	foreach(int i,s;types){
		output~=s;
		output~=".init,";
	}
	output~="))";
	output~=") dg)";
	return output;
}
string ndfieldloop(int I,string order,T...)(){
	//static if(I>=T.length||I>=order.length){return "";}
	//else{
	string output;
	if(I==0){output~="int ret;\n";}
	static if(istuple!(T[I])){
		static assert(0);
	} else {
		output~="foreach(";
		output~=order[I];
		output~=";args[";
		output~=getndindex(order[I]).to!string;
		output~="].toiter){\n";
		static if(I+1<order.length&&I+1<T.length){
			output~=ndfieldloop!(I+1,order,T);
		} else {
			output~="ret=dg(";
			foreach(c;defualtndcharorder[0..I+1]){
				output~=c;
				output~=',';
			}
			output~="F(";
			foreach(c;defualtndcharorder[0..I+1]){
				output~=c;
				output~=',';
			}
			output~="));\n";
			output~="if(ret>1){return ret;}\n";
			output~="if(ret){break;}\n";
		}
		output~="}\n";
	}
	if(I==0){output~="return ret;";}
	return output;
}
unittest{
	//ndfieldheader!("yxz",int,int[],string)().writeln;
	//ndfieldloop!(0,"yxz",int,int[],string)().writeln;
}
auto ndfield(alias F,string order=defualtndcharorder,T...)(T args){
	return mixin(ndfieldheader!(order,T)~"{"~ndfieldloop!(0,order,T)~"}");
}
unittest{
	string[] foo=["foo","bar","baz"];
	foreach(x,y,c;ndfield!((a,b)=>foo[a][b],"xy")(iota(3),iota(3))){
		c.writeln;
	}
	"---".writeln;
	string[][][] bar=[[["bar","foo"],["fiz","buz"]],[["NO"]]];
	foreach(x,y,z,w,c;ndfield!((a,b,c,d)=>bar[a][b][c][d],"zwxy")(iota(2),iota(3),0,0)){
		c.writeln;
	}
	
}
//---
char getndchar(int i){
	if(i<3){return cast(char)('x'+i);}
	assert(i<26);
	return cast(char)('w'-(i-3));
}
enum string defualtndcharorder=iota(26).map!getndchar.to!string;
unittest{
	defualtndcharorder.writeln;
}
int getndindex(char c){
	if(c>='x'&&c<='z'){return c-'x';}
	assert(c>='a'&&c<='w');
	return 3+('w'-c);
}
auto ASCIIMap(alias F)(string r){
	struct Map{
		string r;
		auto front()=>F(r[0]);
		void popFront(){r=r[1..$];}
		bool empty()=>r.length==0;
	}
	return Map(r.dup);
}
unittest{
	//defualtndcharorder.ASCIIMap!getndindex.writeln;
}
struct Tuple(T...){
	enum istuple=true;
	alias type(int I)=T[I];
	T expand; alias expand this;
}
unittest{
	Tuple!(int,string).type!0.stringof.writeln;
}
auto tuple(T...)(T args){
	return Tuple!T(args);
}
unittest{
	auto foo=tuple(1,"hi");
	assert(foo[0]==1);
	assert(foo[1]=="hi");
	auto bar=tuple();
}
enum istuple(T)=is(typeof(T.istuple));
unittest{
	assert(istuple!(typeof(tuple(1,2)))==true);
	assert(istuple!int==false);
}