added "for each k:v in .. do .." statement

doc/script/control_structures.txt

@@ -55,7 +55,24 @@ The results of the expression are combined using the @+@ [[script:operators|oper
 > for each x in ["a","b","c"] do x      ==  "abc"
 > for each x in ["a","b","c"] do [x+x]  ==  ["aa","bb","cc"]
 
-It is also possible to iterate over a range of values
+
+When iterating over a [[type:map]] the key is also available:
+
+>> for each key:variable in list do expression
+
+For example:
+
+> (for each k:v in [name:"Thing", rank:"High"] do
+>     "Its {k} is {v}. "
+> )  ==  "Its name is Thing. Its rank is High. "
+
+When iterating over a list, the key is the index in the list, starting with @0@:
+> (for each k:v in ["a","b","c"] do
+>     ["element {k} is {v}"]
+> )  ==  ["element 0 is a","element 1 is b","element 2 is c"]
+
+
+It is also possible to iterate over a range of values:
 
 > for variable from begin to end do expression
 
@@ -64,6 +81,7 @@ The expression is evaluated for each number from begin to end (including begin,
 --Summary--
 
 ! Syntax				Description
-| @if a then b else c@			If @a@ is @true@ evaluates to @b@, otherwise evaluates to @c@
-| @for each x in list do something@	Does @something@ for each element in a list
-| @for x from 1 to 100 do something@	Does @something@ for all numbers from 1 to 100
+| @if a then b else c@			If @a@ is @true@ evaluates to @b@, otherwise evaluates to @c@.
+| @for each x in list do something@	Does @something@ for each element in a list, adding the results
+| @for each k:v in list do something@	Does @something@ for each element in a map using the key/index in the map.
+| @for x from 1 to 100 do something@	Does @something@ for all numbers from 1 to 100.

src/script/context.cpp

@@ -101,6 +101,20 @@ ScriptValueP Context::eval(const Script& script, bool useScope) {
 					}
 					break;
 				}
+				// Loop over a container, push next key;next value or jump
+				case I_LOOP_WITH_KEY: {
+					ScriptValueP& it = stack[stack.size() - 2]; // second element of stack
+					ScriptValueP key;
+					ScriptValueP val = it->next(&key);
+					if (val) {
+						stack.push_back(val);
+						stack.push_back(key);
+					} else {
+						stack.erase(stack.end() - 2); // remove iterator
+						instr = &script.instructions[i.data];
+					}
+					break;
+				}
 				// Make an object
 				case I_MAKE_OBJECT: {
 					makeObject(i.data);

src/script/dependency.cpp

@@ -239,6 +239,21 @@ ScriptValueP Context::dependencies(const Dependency& dep, const Script& script)
 					}
 					break;
 				}
+				// Loop over a container, push next value or jump (almost as normal)
+				case I_LOOP_WITH_KEY: {
+					ScriptValueP& it = stack[stack.size() - 2]; // second element of stack
+					ScriptValueP key;
+					ScriptValueP val = it->next(&key);
+					if (val) {
+						it = dependency_dummy; // invalidate iterator, so we loop only once
+						stack.push_back(val);
+						stack.push_back(key);
+					} else {
+						stack.erase(stack.end() - 2); // remove iterator
+						instr = &script.instructions[i.data];
+					}
+					break;
+				}
 				// Make an object
 				case I_MAKE_OBJECT: {
 					makeObject(i.data);

src/script/parser.cpp

@@ -483,43 +483,57 @@ void parseExpr(TokenIterator& input, Script& script, Precedence minPrec) {
 			} else if (token == _("for")) {
 				// the loop body should have a net stack effect of 0, but the entire expression of +1
 				// solution: add all results from the body, start with nil
-				if (input.peek() == _("each")) {
-					// for each AAA in BBB do CCC
-					input.read();										// each
-					Token name = input.read();							// AAA
+				bool is_each = input.peek() == _("each");
+				if (is_each) {
+					// for each AAA(:BBB) in CCC do EEE
+					input.read();										// each?
+				} else {
+					// for AAA(:BBB) from CCC to DDD do EEE
+				}
+				// name
+				Token name = input.read();								// AAA
+				if (name != TOK_NAME) {
+					input.expected(_("name"));
+				}
+				Variable var = string_to_variable(name.value);
+				// key:value?
+				bool with_key = input.peek() == _(":");
+				Variable key = (Variable)-1;
+				if (with_key) {
+					input.read();										// :
+					name = input.read();								// BBB
 					if (name != TOK_NAME) {
 						input.expected(_("name"));
 					}
+					key = string_to_variable(name.value);
+					swap(var,key);
+				}
+				// iterator
+				if (is_each) {
 					expectToken(input, _("in"));						// in
-					parseOper(input, script, PREC_AND);					// BBB
+					parseOper(input, script, PREC_AND);					// CCC
 					script.addInstruction(I_UNARY, I_ITERATOR_C);		//		iterator_collection
-					script.addInstruction(I_PUSH_CONST, script_nil);	//		push nil
-					unsigned lblStart = script.addInstruction(I_LOOP);	//		lbl_start: loop lbl_end
-					expectToken(input, _("do"));						// do
-					script.addInstruction(I_SET_VAR,
-										string_to_variable(name.value));//		set name
-					script.addInstruction(I_BINARY, I_POP);				//		 pop
-					parseOper(input, script, PREC_SET, I_BINARY, I_ADD);// CCC;	add
-					script.addInstruction(I_JUMP, lblStart);			//		jump lbl_start
-					script.comeFrom(lblStart);							//		lbl_end:
 				} else {
-					// for AAA from BBB to CCC do DDD
-					Token name = input.read();							// AAA
 					expectToken(input, _("from"));						// from
-					parseOper(input, script, PREC_AND);					// BBB
-					expectToken(input, _("to"));						// to
 					parseOper(input, script, PREC_AND);					// CCC
+					expectToken(input, _("to"));						// to
+					parseOper(input, script, PREC_AND);					// DDD
 					script.addInstruction(I_BINARY, I_ITERATOR_R);		//		iterator_range
-					script.addInstruction(I_PUSH_CONST, script_nil);	//		push nil
-					unsigned lblStart = script.addInstruction(I_LOOP);	//		lbl_start: loop lbl_end
-					expectToken(input, _("do"));						// do
-					script.addInstruction(I_SET_VAR,
-										string_to_variable(name.value));//		set name
+				}
+				script.addInstruction(I_PUSH_CONST, script_nil);		//		push nil
+				unsigned lblStart = script.addInstruction(with_key
+										? I_LOOP_WITH_KEY				//		lbl_start: loop_with_key lbl_end
+										: I_LOOP);						//		lbl_start: loop lbl_end
+				expectToken(input, _("do"));							// do
+				if (with_key) {
+					script.addInstruction(I_SET_VAR, key);				//		set key_name
 					script.addInstruction(I_BINARY, I_POP);				//		 pop
-					parseOper(input, script, PREC_SET, I_BINARY, I_ADD);// DDD;	add
-					script.addInstruction(I_JUMP, lblStart);			//		jump lbl_start
-					script.comeFrom(lblStart);							//		lbl_end:
 				}
+				script.addInstruction(I_SET_VAR, var);					//		set name
+				script.addInstruction(I_BINARY, I_POP);					//		 pop
+				parseOper(input, script, PREC_SET, I_BINARY, I_ADD);	// EEE;	add
+				script.addInstruction(I_JUMP, lblStart);				//		jump lbl_start
+				script.comeFrom(lblStart);								//		lbl_end:
 			} else if (token == _("rgb")) {
 				// rgb(r, g, b)
 				expectToken(input, _("("));

src/script/script.cpp

@@ -97,7 +97,7 @@ ScriptValueP Script::dependencies(Context& ctx, const Dependency& dep) const {
 static const unsigned int INVALID_ADDRESS = 0x03FFFFFF;
 
 unsigned int Script::addInstruction(InstructionType t) {
-	assert( t == I_JUMP || t == I_JUMP_IF_NOT || t == I_LOOP);
+	assert( t == I_JUMP || t == I_JUMP_IF_NOT || t == I_LOOP || t == I_LOOP_WITH_KEY);
 	Instruction i = {t, {INVALID_ADDRESS}};
 	instructions.push_back(i);
 	return getLabel() - 1;
@@ -128,7 +128,8 @@ void Script::addInstruction(InstructionType t, const String& s) {
 void Script::comeFrom(unsigned int pos) {
 	assert( instructions.at(pos).instr == I_JUMP
 	     || instructions.at(pos).instr == I_JUMP_IF_NOT
-	     || instructions.at(pos).instr == I_LOOP);
+	     || instructions.at(pos).instr == I_LOOP
+	     || instructions.at(pos).instr == I_LOOP_WITH_KEY);
 	assert( instructions.at(pos).data == INVALID_ADDRESS );
 	instructions.at(pos).data = (unsigned int)instructions.size();
 }
@@ -163,6 +164,7 @@ String Script::dumpInstr(unsigned int pos, Instruction i) const {
 		case I_SET_VAR:		ret += _("set");		break;
 		case I_MEMBER_C:	ret += _("member_c");	break;
 		case I_LOOP:		ret += _("loop");		break;
+		case I_LOOP_WITH_KEY:ret += _("loop with key"); break;
 		case I_MAKE_OBJECT:	ret += _("make object");break;
 		case I_CALL:		ret += _("call");		break;
 		case I_CLOSURE:		ret += _("closure");	break;
@@ -212,7 +214,7 @@ String Script::dumpInstr(unsigned int pos, Instruction i) const {
 		case I_PUSH_CONST: case I_MEMBER_C:							// const
 			ret += _("\t") + constants[i.data]->typeName();
 			break;
-		case I_JUMP: case I_JUMP_IF_NOT: case I_LOOP: case I_MAKE_OBJECT: case I_CALL: case I_CLOSURE: case I_DUP:	// int
+		case I_JUMP: case I_JUMP_IF_NOT: case I_LOOP: case I_LOOP_WITH_KEY: case I_MAKE_OBJECT: case I_CALL: case I_CLOSURE: case I_DUP:	// int
 			ret += String::Format(_("\t%d"), i.data);
 			break;
 		case I_GET_VAR: case I_SET_VAR: case I_NOP:					// variable
@@ -255,7 +257,7 @@ const Instruction* Script::backtraceSkip(const Instruction* instr, int to_skip)
 				break;
 			case I_JUMP: {
 				if (instr->data > initial) {
-					// we were in an else branch all along, ignore this jump
+					// forward jump, so we were in an else branch all along, ignore this jump
 					return instr + 1;
 				}
 				// there will be a way not to take this jump
@@ -275,6 +277,11 @@ const Instruction* Script::backtraceSkip(const Instruction* instr, int to_skip)
 						// we need to skip two things (iterator+accumulator) instead of one
 						to_skip += 1;
 						break;
+					} else if (instr->instr == I_LOOP_WITH_KEY && instr->data == after_jump) {
+						// same as above,
+						// we need to skip two things (iterator+accumulator) instead of one
+						to_skip += 1;
+						break;
 					} else if (instr->instr == I_JUMP_IF_NOT && instr->data == after_jump) {
 						// code looks like
 						//  1   (nettstack+1)
@@ -293,7 +300,7 @@ const Instruction* Script::backtraceSkip(const Instruction* instr, int to_skip)
 				++instr; // compensate for the -- in the outer loop
 				break;
 			}
-			case I_JUMP_IF_NOT: case I_LOOP:
+			case I_JUMP_IF_NOT: case I_LOOP: case I_LOOP_WITH_KEY:
 				return nullptr; // give up
 			default:
 				break; // nett stack effect 0

src/script/script.hpp

@@ -32,16 +32,17 @@ enum InstructionType
 ,	I_MEMBER_C		= 6  ///< arg = const name : finds a member of the top of the stack replaces the top of the stack with the member
 ,	I_LOOP			= 7  ///< arg = address    : loop over the elements of an iterator, which is the *second* element of the stack (this allows for combing the results of multiple iterations)
 					     ///<                    at the end performs a jump and pops the iterator. note: The second element of the stack must be an iterator!
-,	I_MAKE_OBJECT   = 8  ///< arg = int        : make a list/map with n elements, pops 2n values of the stack, n key/value pairs
+,	I_LOOP_WITH_KEY	= 8  ///< arg = address    : loop, but also pushing the key
+,	I_MAKE_OBJECT   = 9  ///< arg = int        : make a list/map with n elements, pops 2n values of the stack, n key/value pairs
 	// Functions
-,	I_CALL			= 9  ///< arg = int, n*var : call the top item of the stack, with the given number of arguments (set with SET_VAR, but in the activation record of the call)
-,	I_CLOSURE       = 10 ///< arg = int, n*var : construct a call closure object with the given arguments
+,	I_CALL			= 10 ///< arg = int, n*var : call the top item of the stack, with the given number of arguments (set with SET_VAR, but in the activation record of the call)
+,	I_CLOSURE       = 11 ///< arg = int, n*var : construct a call closure object with the given arguments
 	// Simple instructions
-,	I_UNARY			= 11 ///< arg = 1ary instr : pop 1 value,  apply a function, push the result
-,	I_BINARY		= 12 ///< arg = 2ary instr : pop 2 values, apply a function, push the result
-,	I_TERNARY		= 13 ///< arg = 3ary instr : pop 3 values, apply a function, push the result
-,	I_QUATERNARY	= 14 ///< arg = 4ary instr : pop 4 values, apply a function, push the result
-,	I_DUP			= 15 ///< arg = int        : duplicate the k-from-top element of the stack
+,	I_UNARY			= 12 ///< arg = 1ary instr : pop 1 value,  apply a function, push the result
+,	I_BINARY		= 13 ///< arg = 2ary instr : pop 2 values, apply a function, push the result
+,	I_TERNARY		= 14 ///< arg = 3ary instr : pop 3 values, apply a function, push the result
+,	I_QUATERNARY	= 15 ///< arg = 4ary instr : pop 4 values, apply a function, push the result
+,	I_DUP			= 16 ///< arg = int        : duplicate the k-from-top element of the stack
 };
 
 /// Types of unary instructions (taking one argument from the stack)
@@ -96,13 +97,13 @@ enum QuaternaryInstructionType
  *  Then the instr? member gives the actual instruction to perform
  */
 struct Instruction {
-	InstructionType instr : 5;
+	InstructionType instr : 6;
 	union {
-		unsigned int				data   : 27;
-		UnaryInstructionType		instr1 : 27;
-		BinaryInstructionType		instr2 : 27;
-		TernaryInstructionType		instr3 : 27;
-		QuaternaryInstructionType	instr4 : 27;
+		unsigned int				data   : 26;
+		UnaryInstructionType		instr1 : 26;
+		BinaryInstructionType		instr2 : 26;
+		TernaryInstructionType		instr3 : 26;
+		QuaternaryInstructionType	instr4 : 26;
 	};
 };
 

src/script/value.cpp

@@ -128,17 +128,17 @@ class ScriptRangeIterator : public ScriptIterator {
   public:
 	// Construct a range iterator with the given bounds (inclusive)
 	ScriptRangeIterator(int start, int end)
-		: pos(start), end(end) {}
+		: pos(start), start(start), end(end) {}
 	virtual ScriptValueP next(ScriptValueP* key_out) {
 		if (pos <= end) {
-			if (key_out) *key_out = to_script(pos);
+			if (key_out) *key_out = to_script(pos-start);
 			return to_script(pos++);
 		} else {
 			return ScriptValueP();
 		}
 	}
   private:
-	int pos, end;
+	int pos, start, end;
 };
 
 ScriptValueP rangeIterator(int start, int end) {