Added scripting support; not yet integrated with the rest of the app.

git-svn-id: svn://svn.code.sf.net/p/magicseteditor/code/trunk@13 0fc631ac-6414-0410-93d0-97cfa31319b6

src/script/context.cpp

@@ -0,0 +1,291 @@
+//+----------------------------------------------------------------------------+
+//| Description:  Magic Set Editor - Program to make Magic (tm) cards          |
+//| Copyright:    (C) 2001 - 2006 Twan van Laarhoven                           |
+//| License:      GNU General Public License 2 or later (see file COPYING)     |
+//+----------------------------------------------------------------------------+
+
+// ----------------------------------------------------------------------------- : Includes
+
+#include <script/context.hpp>
+#include <util/error.hpp>
+#include <iostream>
+
+// ----------------------------------------------------------------------------- : Context
+
+Context::Context()
+	: level(0)
+{}
+
+// ----------------------------------------------------------------------------- : Evaluate
+
+// Perform a unary simple instruction, store the result in a (not in *a)
+void instrUnary  (UnaryInstructionType   i, ScriptValueP& a);
+
+// Perform a binary simple instruction, store the result in a (not in *a)
+void instrBinary (BinaryInstructionType  i, ScriptValueP& a, const ScriptValueP& b);
+
+// Perform a ternary simple instruction, store the result in a (not in *a)
+void instrTernary(TernaryInstructionType i, ScriptValueP& a, const ScriptValueP& b, const ScriptValueP& c);
+
+
+ScriptValueP Context::eval(const Script& script, bool useScope) {
+	size_t stack_size = stack.size();
+	size_t scope = useScope ? openScope() : 0;
+	try {
+		// Instruction pointer
+		const Instruction* instr = &script.instructions[0];
+		
+		// Loop until we are done
+		while (true) {
+			assert(instr < &*script.instructions.end());
+			// debug
+//			cout << script.dumpInstr(instr - &script.instructions[0], *instr) << endl;
+			// Evaluate the current instruction
+			Instruction i = *instr++;
+			switch (i.instr) {
+				case I_NOP: break;
+				// Push a constant
+				case I_PUSH_CONST: {
+					stack.push_back(script.constants[i.data]);
+					break;
+				}
+				// Pop top value
+				case I_POP: {
+					stack.pop_back();
+					break;
+				}
+				// Jump
+				case I_JUMP: {
+					instr = &script.instructions[i.data];
+					break;
+				}
+				// Conditional jump
+				case I_JUMP_IF_NOT: {
+					int condition = *stack.back();
+					stack.pop_back();
+					if (!condition) {
+						instr = &script.instructions[i.data];
+					}
+					break;
+				}
+				
+				// Get a variable
+				case I_GET_VAR: {
+					ScriptValueP value = variables[i.data].value;
+					if (!value) throw ScriptError(_("Variable not set: ") + variableToString(i.data));
+					stack.push_back(value);
+					break;
+				}
+				// Set a variable
+				case I_SET_VAR: {
+					setVariable(i.data, stack.back());
+					break;
+				}
+				
+				// Get an object member
+				case I_MEMBER_C: {
+					stack.back() = stack.back()->getMember(*script.constants[i.data]);
+					break;
+				}
+				// Loop over a container, push next value or jump
+				case I_LOOP: {
+					ScriptValueP& it = stack[stack.size() - 2]; // second element of stack
+					assert(dynamic_pointer_cast<ScriptIterator>(it)); // top of stack must be an iterator
+					ScriptValueP val = static_pointer_cast<ScriptIterator>(it)->next();
+					if (val) {
+						stack.push_back(val);
+					} else {
+						stack.erase(stack.end() - 2); // remove iterator
+						instr = &script.instructions[i.data];
+					}
+					break;
+				}
+				
+				// Function call
+				case I_CALL: {
+					// new scope
+					size_t scope = openScope();
+					// prepare arguments
+					for (unsigned int j = 0 ; j < i.data ; ++j) {
+						setVariable(instr[i.data - j - 1].data, stack.back());
+						stack.pop_back();
+					}
+					instr += i.data; // skip arguments
+					// get function and call
+					stack.back() = stack.back()->eval(*this);
+					// restore scope
+					closeScope(scope);
+					break;
+				}
+				// Function return
+				case I_RET: {
+					// restore shadowed variables
+					if (useScope) closeScope(scope);
+					// return top of stack
+					ScriptValueP result = stack.back();
+					stack.pop_back();
+					assert(stack.size() == stack_size); // we end up with the same stack
+					return result;
+				}
+				
+				// Simple instruction: unary
+				case I_UNARY: {
+					instrUnary(i.instr1, stack.back());
+//					cout << "\t\t-> " << (String)*stack.back() << endl;
+					break;
+				}
+				// Simple instruction: binary
+				case I_BINARY: {
+					ScriptValueP  b = stack.back(); stack.pop_back();
+					ScriptValueP& a = stack.back();
+					instrBinary(i.instr2, a, b);
+//					cout << "\t\t-> " << (String)*stack.back() << endl;
+					break;
+				}
+				// Simple instruction: ternary
+				case I_TERNARY: {
+					ScriptValueP  c = stack.back(); stack.pop_back();
+					ScriptValueP  b = stack.back(); stack.pop_back();
+					ScriptValueP& a = stack.back();
+					instrTernary(i.instr3, a, b, c);
+//					cout << "\t\t-> " << (String)*stack.back() << endl;
+					break;
+				}
+			}
+		}
+		
+	} catch (...) {
+		// cleanup after an exception
+		if (scope) closeScope(scope); // restore scope
+		stack.resize(stack_size);     // restore stack
+		throw; // rethrow
+	}
+}
+
+void Context::setVariable(const String& name, const ScriptValueP& value) {
+	setVariable(stringToVariable(name), value);
+}
+
+void Context::setVariable(int name, const ScriptValueP& value) {
+	Variable& var = variables[name];
+	if (var.value && var.level < level) {
+		// keep shadow copy
+		Binding bind = {name, var};
+		shadowed.push_back(bind);
+	}
+	var.level = level;
+	var.value = value;
+}
+
+ScriptValueP Context::getVariable(const String& name) {
+	ScriptValueP value = variables[stringToVariable(name)].value;
+	if (!value) throw ScriptError(_("Variable not set: ") + name);
+	return value;
+}
+
+ScriptValueP Context::getVariableOrNil(const String& name) {
+	return variables[stringToVariable(name)].value;
+}
+
+
+size_t Context::openScope() {
+	level += 1;
+	return shadowed.size();
+}
+void Context::closeScope(size_t scope) {
+	assert(level > 0);
+	assert(scope <= shadowed.size());
+	level -= 1;
+	// restore shadowed variables
+	while (shadowed.size() > scope) {
+		variables[shadowed.back().variable] = shadowed.back().value;
+		shadowed.pop_back();
+	}
+}
+
+// ----------------------------------------------------------------------------- : Simple instructions : unary
+
+void instrUnary  (UnaryInstructionType   i, ScriptValueP& a) {
+	switch (i) {
+		case I_ITERATOR_C:
+			a = a->makeIterator();
+			break;
+		case I_NEGATE:
+			a = toScript(-(int)*a);
+			break;
+		case I_NOT:
+			a = toScript(!(int)*a);
+			break;
+	}
+}
+
+// ----------------------------------------------------------------------------- : Simple instructions : binary
+
+// operator on ints
+#define OPERATOR_I(OP)											\
+	a = toScript((int)*a  OP  (int)*b);							\
+	break
+
+// operator on doubles or ints
+#define OPERATOR_DI(OP)											\
+	if (at == SCRIPT_DOUBLE || bt == SCRIPT_DOUBLE) {			\
+		a = toScript((double)*a  OP  (double)*b);				\
+	} else {													\
+		a = toScript((int)*a     OP  (int)*b);					\
+	}															\
+	break
+
+// operator on strings or doubles or ints
+#define OPERATOR_SDI(OP)										\
+	if (at == SCRIPT_STRING || bt == SCRIPT_STRING) {			\
+		a = toScript((String)*a  OP  (String)*b);				\
+	} else if (at == SCRIPT_DOUBLE || bt == SCRIPT_DOUBLE) {	\
+		a = toScript((double)*a  OP  (double)*b);				\
+	} else {													\
+		a = toScript((int)*a     OP  (int)*b);					\
+	}															\
+	break
+
+void instrBinary (BinaryInstructionType  i, ScriptValueP& a, const ScriptValueP& b) {
+	ScriptType at = a->type(), bt = b->type();
+	switch (i) {
+		case I_MEMBER:
+			a = a->getMember(*b);
+			break;
+		case I_ITERATOR_R:
+			a = rangeIterator(*a, *b);
+			break;
+		case I_ADD: // add is quite overloaded
+			if (at == SCRIPT_NIL) {
+				a = b;
+			} else if (bt == SCRIPT_NIL) {
+				// a = a;
+			//} else if (a->likesFunction() && b->likesFunction()) {
+			//	a = compose(a, b);
+			} else if (at == SCRIPT_STRING || bt == SCRIPT_STRING) {
+				a = toScript((String)*a  +  (String)*b);
+			} else if (at == SCRIPT_DOUBLE || bt == SCRIPT_DOUBLE) {
+				a = toScript((double)*a  +  (double)*b);
+			} else {
+				a = toScript((int)*a     +  (int)*b);
+			}
+			break;
+		case I_SUB:		OPERATOR_DI(-);
+		case I_MUL:		OPERATOR_DI(*);
+		case I_DIV:		OPERATOR_DI(/);
+		case I_MOD: // fmod
+		case I_AND:		OPERATOR_I(&&);
+		case I_OR:		OPERATOR_I(||);
+		case I_EQ:		OPERATOR_SDI(==);
+		case I_NEQ:		OPERATOR_SDI(!=);
+		case I_LT:		OPERATOR_DI(<);
+		case I_GT:		OPERATOR_DI(>);
+		case I_LE:		OPERATOR_DI(<=);
+		case I_GE:		OPERATOR_DI(>=);
+	}
+}
+
+// ----------------------------------------------------------------------------- : Simple instructions : ternary
+
+void instrTernary(TernaryInstructionType i, ScriptValueP& a, const ScriptValueP& b, const ScriptValueP& c) {
+}

src/script/context.hpp

@@ -0,0 +1,99 @@
+//+----------------------------------------------------------------------------+
+//| Description:  Magic Set Editor - Program to make Magic (tm) cards          |
+//| Copyright:    (C) 2001 - 2006 Twan van Laarhoven                           |
+//| License:      GNU General Public License 2 or later (see file COPYING)     |
+//+----------------------------------------------------------------------------+
+
+#ifndef HEADER_SCRIPT_CONTEXT
+#define HEADER_SCRIPT_CONTEXT
+
+// ----------------------------------------------------------------------------- : Includes
+
+#include <script/script.hpp>
+
+class Dependency;
+
+// ----------------------------------------------------------------------------- : VectorIntMap
+
+/// A map like data structure that stores the elements in a vector.
+/** K should be an integer type, the keys should be dense. */
+template <typename K, typename V>
+class VectorIntMap {
+  public:
+	inline V& operator [] (K key) {
+		if (values.size() <= key) {
+			values.resize(key + 1);
+		}
+		return values[key];
+	}
+  private:
+	vector<V> values;
+};
+
+// ----------------------------------------------------------------------------- : Context
+
+/// Context for script evaluation
+class Context {
+  public:
+	Context();
+	
+	/// Evaluate a script inside this context.
+	/** This function is safely reentrant.
+	 *  @param openScope if false, variables set in this eval call will leak out.
+	 */
+	ScriptValueP eval(const Script& script, bool openScope = true);
+	
+	/// Analyze the dependencies of a script
+	/** All things the script depends on are marked with signalDependent(dep).
+	 *  The return value of this function should be ignored
+	 */
+	ScriptValueP dependencies(const Dependency& dep, const Script& script);
+		
+	/// Set a variable to a new value (in the current scope)
+	void setVariable(const String& name, const ScriptValueP& value);
+	
+	/// Get the value of a variable, throws if it not set
+	ScriptValueP getVariable(const String& name);
+	/// Get the value of a variable, returns nil if it is not set
+	ScriptValueP getVariableOrNil(const String& name);
+	
+  public:// public for FOR_EACH
+	/// Record of a variable
+	struct Variable {
+		unsigned int level; ///< Scope level on which this variable was set
+		ScriptValueP value; ///< Value of this variable
+	};
+	/// Record of a variable binding that is being shadowed (overwritten) by another binding
+	struct Binding {
+		int      variable; ///< Name of the overwritten variable.
+		Variable value;    ///< Old value of that variable.
+	};
+  private:
+	/// Variables, indexed by integer naem (using stringToVariable)
+	VectorIntMap<unsigned int, Variable> variables;
+	/// Shadowed variable bindings
+	vector<Binding> shadowed;
+	/// Number of scopes opened
+	unsigned int level;
+	/// Stack of values
+	vector<ScriptValueP> stack;	
+	
+	// utility types for dependency analysis
+	struct Jump;
+	struct JumpOrder;
+	
+	/// Set a variable to a new value (in the current scope)
+	void setVariable(int name, const ScriptValueP& value);
+	/// Open a new scope
+	/** returns the number of shadowed binding before that scope */
+	size_t openScope();
+	/// Close a scope, must be passed a value from openScope
+	void closeScope(size_t scope);
+	/// Return the bindings in the current scope
+	void getBindings(size_t scope, vector<Binding>&);
+	/// Remove all bindings made in the current scope
+	void resetBindings(size_t scope);
+};
+
+// ----------------------------------------------------------------------------- : EOF
+#endif

src/script/dependency.cpp

@@ -0,0 +1,322 @@
+//+----------------------------------------------------------------------------+
+//| Description:  Magic Set Editor - Program to make Magic (tm) cards          |
+//| Copyright:    (C) 2001 - 2006 Twan van Laarhoven                           |
+//| License:      GNU General Public License 2 or later (see file COPYING)     |
+//+----------------------------------------------------------------------------+
+
+// ----------------------------------------------------------------------------- : Includes
+
+#include <script/context.hpp>
+#include <util/error.hpp>
+#include <queue>
+
+DECLARE_TYPEOF_COLLECTION(ScriptValueP);
+DECLARE_TYPEOF_COLLECTION(Context::Binding);
+
+// ----------------------------------------------------------------------------- : Dummy values
+
+// A dummy type used during dependency analysis,
+// it simply supresses all error messages.
+class DependencyDummy : public ScriptIterator {
+  public:
+	virtual ScriptType type() const { return SCRIPT_DUMMY; }
+	virtual String typeName() const { return "dummy"; }
+	virtual ScriptValueP next() { return ScriptValueP(); }
+};
+
+ScriptValueP dependencyDummy(new DependencyDummy);
+
+ScriptValueP unified(const ScriptValueP& a, const ScriptValueP& b);
+
+// A script value that is a 'union' of two values.
+/* During actual execution the value could be either a *or* b,
+ * So it has the dependency characteristics of both.
+ */
+class DependencyUnion : public ScriptValue {
+  public:
+	DependencyUnion(const ScriptValueP& a, const ScriptValueP& b)
+		: a(a), b(b)
+	{}
+	
+	virtual ScriptType type() const { return SCRIPT_DUMMY; }
+	virtual String typeName() const { return "union of " + a->typeName() + " and " + b->typeName(); }
+	
+	virtual ScriptValueP dependencies(Context& ctx, const Dependency& dep) const {
+		return unified( a->dependencies(ctx,dep), b->dependencies(ctx,dep));
+	}
+	virtual ScriptValueP makeIterator() const {
+		return unified(a->makeIterator(), b->makeIterator());
+	}
+  private:
+	ScriptValueP a, b;
+};
+
+// Unify two values from different execution paths
+void unify(ScriptValueP& a, const ScriptValueP& b) {
+	if (a != b) a = new_intrusive2<DependencyUnion>(a,b);
+}
+// Unify two values from different execution paths
+ScriptValueP unified(const ScriptValueP& a, const ScriptValueP& b) {
+	if (a == b) return a;
+	else        return new_intrusive2<DependencyUnion>(a,b);
+}
+
+// ----------------------------------------------------------------------------- : Jump record
+
+// Utility class: a jump that has been postponed
+struct Context::Jump {
+	const Instruction*   target;		///< Target of the jump
+	vector<ScriptValueP> stack_top;		///< The top part of the stack, everything local to the current call
+	vector<Binding>      bindings;		///< The bindings made up to this point in the current scope
+};
+// an ordering on jumps by their target, lowest target = highest priority
+struct Context::JumpOrder {
+	inline bool operator () (Jump* a, Jump* b) {
+		return a->target > b->target;
+	}
+};
+
+// ----------------------------------------------------------------------------- : Dependency analysis
+
+ScriptValueP Context::dependencies(const Dependency& dep, const Script& script) {
+	// Dependency analysis proceeds in the same way as normal evaluation.
+	// Operator calls will be replaced by "push dummy", we don't care about values.
+	// Only the operators left are:
+	//   - member operator; and it signals a dependency.
+	//   - looper construction
+	//   - + for function composition
+	// Jumps are tricky:
+	//   - I_JUMP:        Just follow them, but see below
+	//   - I_JUMP_IF_NOT: We don't know the value of the condition, evaluate both branches.
+	//                    The simple solution would be to use recursion to fork off one of the cases.
+	//                    This could result in an exponential increase in execution time,
+	//                    because the analysis after an if statement is duplicated.
+	//                    A better solution is to evalutate branches 'in parallel'. After the if statement
+	//                    the net stack effect is +1, the top element will then be a DependencyUnion object.
+	//                    To detect the joining of the branches we look for I_JUMPs, the non jumping branch will have
+	//                    a I_JUMP at the end, when we encounter it we start evaluating the other if branch.
+	//   - I_LOOP:        We want to prevent infinite loops, the solution is that after the first
+	//                    iteration we set the looper to a dummy value, so the loop is only executed once.
+	//                    TODO: This could result in false negatives when iterating over things like fields.
+	//                          We ignore this, because loops are usually only used for exporting, where dependency
+	//                          analysis is not used anyway.
+	// Variable assignments are performed as normall.
+	
+	// Scope for evaluating this script.
+	size_t stack_size = stack.size();
+	size_t scope      = openScope();
+	
+	// Forward jumps waiting to be performed, by order of target (descending)
+	priority_queue<Jump*,vector<Jump*>,JumpOrder> jumps;
+	
+	try {
+		// Instruction pointer
+		const Instruction* instr = &script.instructions[0];
+		
+		// Loop until we are done
+		while (true) {
+			assert(instr < &*script.instructions.end());
+			// Is there a jump going here?
+			// If so, unify with current execution path
+			while (!jumps.empty() && jumps.top()->target == instr) {
+				// unify with current execution path
+				Jump* j = jumps.top(); jumps.pop();
+				// unify stack
+				assert(stack_size + j->stack_top.size()  ==  stack.size());
+				for (size_t i = 0; i < j->stack_top.size() ; ++i) {
+					unify(stack[stack_size + i], j->stack_top[i]);
+				}
+				// unify bindings
+				FOR_EACH(v, j->bindings) {
+					unify(variables[v.variable].value, v.value.value);
+				}
+				delete j;
+			}
+			
+			// Analyze the current instruction
+			Instruction i = *instr++;
+			switch (i.instr) {
+				case I_NOP: break;
+				// Push a constant (as normal)
+				case I_PUSH_CONST: {
+					stack.push_back(script.constants[i.data]);
+					break;
+				}
+				// Pop top value (as normal)
+				case I_POP: {
+					stack.pop_back();
+					break;
+				}
+				// Jump
+				case I_JUMP: {
+					if (&script.instructions[i.data] >= instr) {
+						// forward jump
+						// create jump record
+						Jump* jump = new Jump;
+						jump->target = &script.instructions[i.data];
+						jump->stack_top.assign(stack.begin() + stack_size, stack.end());
+						getBindings(scope, jump->bindings);
+						jumps.push(jump);
+						// clear scope
+						stack.resize(stack_size);
+						resetBindings(scope);
+						// we don't follow this jump just yet, there may be jumps that point to earlier positions
+						Jump* jumpTo = jumps.top(); jumps.pop();
+						instr = jumpTo->target;
+						FOR_EACH(s, jumpTo->stack_top) stack.push_back(s);
+						FOR_EACH(b, jumpTo->bindings)  setVariable(b.variable, b.value.value);
+						delete jumpTo;
+					} else {
+						// backward jump: just follow it, someone else (I_LOOP) will make sure
+						// we don't go into an infinite loop
+						instr = &script.instructions[i.data];
+					}
+					break;
+				}
+				// Conditional jump
+				case I_JUMP_IF_NOT: {
+					stack.pop_back(); // condition
+					// create jump record
+					Jump* jump = new Jump;
+					jump->target = &script.instructions[i.data];
+					assert(jump->target >= instr); // jumps must be forward
+					jump->stack_top.assign(stack.begin() + stack_size, stack.end());
+					getBindings(scope, jump->bindings);
+					jumps.push(jump);
+					// just fall through for the case that the condition holds
+					break;
+				}
+				
+				// Get an object member (almost as normal)
+				case I_MEMBER_C: {
+					String name = *script.constants[i.data];
+					stack.back()->signalDependent(*this, dep, name); // dependency on member
+					stack.back() = stack.back()->getMember(name);
+					break;
+				}
+				// Loop over a container, push next value or jump (almost as normal)
+				case I_LOOP: {
+					ScriptValueP& it = stack[stack.size() - 2]; // second element of stack
+					assert(dynamic_pointer_cast<ScriptIterator>(it)); // top of stack must be an iterator
+					ScriptValueP val = static_pointer_cast<ScriptIterator>(it)->next();
+					if (val) {
+						it = dependencyDummy; // invalidate iterator, so we loop only once
+						stack.push_back(val);
+					} else {
+						stack.erase(stack.end() - 2); // remove iterator
+						instr = &script.instructions[i.data];
+					}
+					break;
+				}
+				
+				// Function call (as normal)
+				case I_CALL: {
+					// new scope
+					size_t scope = openScope();
+					// prepare arguments
+					for (unsigned int j = 0 ; j < i.data ; ++j) {
+						setVariable(instr[i.data - j - 1].data, stack.back());
+						stack.pop_back();
+					}
+					instr += i.data; // skip arguments, there had better not be any jumps into the argument list
+					// get function and call
+					stack.back() = stack.back()->dependencies(*this, dep);
+					// restore scope
+					closeScope(scope);
+					break;
+				}
+				// Function return (as normal)
+				case I_RET: {
+					closeScope(scope);
+					// return top of stack
+					ScriptValueP result = stack.back();
+					stack.pop_back();
+					assert(stack.size() == stack_size); // we end up with the same stack
+					assert(jumps.empty());              // no open jump records
+					return result;
+				}
+				
+				// Get a variable (almost as normal)
+				case I_GET_VAR: {
+					ScriptValueP value = variables[i.data].value;
+					if (!value) value = scriptNil; // no errors here
+					stack.push_back(value);
+					break;
+				}
+				// Set a variable (as normal)
+				case I_SET_VAR: {
+					setVariable(i.data, stack.back());
+					break;
+				}
+				
+				// Simple instruction: unary
+				case I_UNARY: {
+					ScriptValueP& a = stack.back();
+					switch (i.instr1) {
+						case I_ITERATOR_C:
+							a = a->makeIterator(); // as normal
+							break;
+						default:
+							a = dependencyDummy;
+					}
+					break;
+				}
+				// Simple instruction: binary
+				case I_BINARY: {
+					ScriptValueP  b = stack.back(); stack.pop_back();
+					ScriptValueP& a = stack.back();
+					switch (i.instr2) {
+						case I_ITERATOR_R:
+							a = rangeIterator(0,0); // values don't matter
+							break;
+						case I_MEMBER: {
+							String name = *b;
+							a->signalDependent(*this, dep, name); // dependency on member
+							a = a->getMember(name);
+							break;
+						} case I_ADD:
+							unify(a, b); // may be function composition
+							break;
+						default:
+							a = dependencyDummy;
+					}
+					break;
+				}
+				// Simple instruction: ternary
+				case I_TERNARY: {
+					ScriptValueP  c = stack.back(); stack.pop_back();
+					ScriptValueP  b = stack.back(); stack.pop_back();
+					ScriptValueP& a = stack.back();
+					a = dependencyDummy;
+					break;
+				}
+			}
+		}
+	} catch (...) {
+		// cleanup after an exception
+		// the only place where exceptions should be possible is in someValue->getMember
+		if (scope) closeScope(scope); // restore scope
+		stack.resize(stack_size);     // restore stack
+		// delete jump records
+		while(jumps.empty()) {
+			delete jumps.top();
+			jumps.pop();
+		}
+		throw; // rethrow
+	}
+}
+
+void Context::getBindings(size_t scope, vector<Binding>& bindings) {
+	for (size_t i = scope + 1 ; i < shadowed.size() ; ++i) {
+		Binding b = {shadowed[i].variable, variables[shadowed[i].variable]};
+		bindings.push_back(b);
+	}
+}
+
+void Context::resetBindings(size_t scope) {
+	// same as closeScope()
+	while (shadowed.size() > scope) {
+		variables[shadowed.back().variable] = shadowed.back().value;
+		shadowed.pop_back();
+	}
+}

src/script/parser.cpp

@@ -0,0 +1,506 @@
+//+----------------------------------------------------------------------------+
+//| Description:  Magic Set Editor - Program to make Magic (tm) cards          |
+//| Copyright:    (C) 2001 - 2006 Twan van Laarhoven                           |
+//| License:      GNU General Public License 2 or later (see file COPYING)     |
+//+----------------------------------------------------------------------------+
+
+// ----------------------------------------------------------------------------- : Includes
+
+#include <script/script.hpp>
+#include <script/parser.hpp>
+#include <util/error.hpp>
+#include <stack>
+#include <boost/lexical_cast.hpp> //%%
+
+DECLARE_TYPEOF_COLLECTION(int);
+
+// ----------------------------------------------------------------------------- : Tokenizing : class
+
+enum TokenType
+{	TOK_NAME	// abc
+,	TOK_INT		// 123
+,	TOK_DOUBLE	// 123.0
+,	TOK_STRING	// "asdf"
+,	TOK_OPER	// + - * / . ;
+,	TOK_LPAREN	// ( { [
+,	TOK_RPAREN	// ) } ]
+,	TOK_NEWLINE	// newline
+,	TOK_EOF		// end of input
+};
+
+/// Tokens produced by the TokenIterator
+struct Token {
+	TokenType type;
+	String    value;
+	
+	inline operator == (TokenType     t) const { return type  == t; }
+	inline operator != (TokenType     t) const { return type  != t; }
+	inline operator == (const String& s) const { return type != TOK_STRING && value == s; }
+	inline operator != (const String& s) const { return type == TOK_STRING || value != s; }
+};
+
+
+/// Iterator over a string, one token at a time
+class TokenIterator {
+  public:
+	TokenIterator(const String& str);
+	
+	/// Peek at the next token, doesn't move to the one after that
+	/** Can peek further forward by using higher values of offset.
+	 *  offset=0 returns the last token that was read, or newline if putBack() was used.
+	 */
+	const Token& peek(size_t offset = 1);
+	/// Retrieve the next token
+	const Token& read();
+	/// Put back a token
+	/** Only one token can be correctly put back, the put back token will read as a newline.
+	 */
+	void putBack();
+	
+  private:
+	String input;
+	size_t pos;
+	vector<Token> buffer;     // buffer of unread tokens, front() = current
+	stack<bool>   openBraces; // braces we entered, true if the brace was from a smart string escape
+	/// Read the next token, and add it to the buffer
+	void addToken();
+	/// Read the next token which is a string (after the opening ")
+	void addStringToken();
+};
+
+// ----------------------------------------------------------------------------- : Characters
+
+// TODO: isxx -> isXX!
+
+bool isAlpha_(Char c) { return isAlpha(c) || c==_('_'); }
+bool isAlnum_(Char c) { return isAlnum(c) || c==_('_'); }
+bool isOper  (Char c) { return c==_('+') || c==_('-') || c==_('*') || c==_('/') || c==_('!') || c==_('.') ||
+                               c==_(':') || c==_('=') || c==_('<') || c==_('>') || c==_(';') || c==_(',');  }
+bool isLparen(Char c) { return c==_('(') || c==_('[') || c==_('{'); }
+bool isRparen(Char c) { return c==_(')') || c==_(']') || c==_('}'); }
+bool isDigitOrDot(Char c) { return isDigit(c) || c==_('.'); }
+bool isLongOper(const String& s) { return s==_(":=") || s==_("==") || s==_("!=") || s==_("<=") || s==_(">="); }
+
+// ----------------------------------------------------------------------------- : Tokenizing
+
+TokenIterator::TokenIterator(const String& str)
+	: input(str)
+	, pos(0)
+{}
+
+const Token& TokenIterator::peek(size_t offset) {
+	// read the next token until we have enough
+	while (buffer.size() <= offset) {
+		addToken();
+	}
+	return buffer[offset];
+}
+
+const Token& TokenIterator::read() {
+	if (!buffer.empty()) buffer.erase(buffer.begin());
+	return peek(0);
+}
+
+void TokenIterator::putBack() {
+	Token t = {TOK_NEWLINE, "\n"};
+	buffer.insert(buffer.begin(), t);
+}
+
+void TokenIterator::addToken() {
+	if (pos >= input.size()) {
+		// EOF
+		Token t = {TOK_EOF, "end of input"};
+		buffer.push_back(t);
+		return;
+	}
+	// read a character from the input
+	Char c = input[pos++];			//% input.GetChar(pos++);
+	if (c == _('\n')) {
+		Token t = { TOK_NEWLINE, "newline" };
+		buffer.push_back(t);
+	} else if (isSpace(c)) {
+		// ignore
+	} else if (isAlpha(c)) {
+		// name
+		size_t start = pos - 1;
+		while (pos < input.size() && isalnum(input[pos])) ++pos; //%% isAlnum_(input.getChar(pos))) pos++;
+		Token t = {TOK_NAME, cannocialNameForm(input.substr(start, pos-start)) }; // convert name to cannocial form
+		buffer.push_back(t);
+	} else if (isDigit(c)) {
+		// number
+		size_t start = pos - 1;
+		while (pos < input.size() && isDigitOrDot(input[pos])) ++pos;
+		String num = input.substr(start, pos-start);
+		Token t = {
+			num.find_first_of('.') == String::npos ? TOK_INT : TOK_DOUBLE,
+			num
+		};
+		buffer.push_back(t);
+	} else if (isOper(c)) {
+		// operator
+		Token t = { TOK_OPER };
+		if (pos < input.size() && isLongOper(input.substr(pos - 1, 2))) {
+			// long operator
+			t.value = input.substr(pos - 1, 2);
+			pos += 1;
+		} else {
+			t.value = input.substr(pos - 1, 1);
+		}
+		buffer.push_back(t);
+	} else if (c==_('"')) {
+		// string
+		addStringToken();
+	} else if (c == _('}') && !openBraces.empty() && openBraces.top()) {
+		// closing smart string, resume to string parsing
+		//   "a{e}b"  -->  "a"  "{  e  }"  "b"
+		openBraces.pop();
+		Token t2 = {TOK_RPAREN, _("}\"")};
+		buffer.push_back(t2);
+		addStringToken();
+	} else if (isLparen(c)) {
+		// paranthesis/brace
+		openBraces.push(false);
+		Token t = { TOK_LPAREN, String(1,c) };
+		buffer.push_back(t);
+	} else if (isRparen(c)) {
+		// paranthesis/brace
+		if (!openBraces.empty()) openBraces.pop();
+		Token t = { TOK_RPAREN, String(1,c) };
+		buffer.push_back(t);
+	} else if(c==_('#')) {
+		// comment untill end of line
+		while (pos < input.size() && input[pos] != _('\n')) ++pos;
+	} else {
+		throw ScriptParseError(_("Unknown character in script: '") + String(1,c) + _("'"));
+		assert(false);
+	}
+}
+
+void TokenIterator::addStringToken() {
+	Token t = {TOK_STRING};
+	while (true) {
+		if (pos >= input.size()) throw ScriptParseError(_("Unexpected end of input in string constant"));
+		Char c = input[pos++];			//% input.GetChar(pos++);
+		// parse the string constant
+		if (c == _('"')) {
+			// end of string
+			buffer.push_back(t);
+			return;
+		} else if (c == _('\\')) {
+			// escape
+			if (pos >= input.size()) throw ScriptParseError(_("Unexpected end of input in string constant"));
+			c = input[pos++];
+			if (c == _('n')) t.value += _('\n');
+			if (c == _('<')) t.value += _('\1'); // escape for <
+			else             t.value += c;       // \ or { or "
+		} else if (c == _('{')) {
+			// smart string
+			//   "a{e}b"  -->  "a"  "{  e  }"  "b"
+			buffer.push_back(t);
+			openBraces.push(true);
+			Token t2 = {TOK_LPAREN, _("\"{")};
+			buffer.push_back(t2);
+			return;
+		} else {
+			t.value += c;
+		}
+	}
+}
+
+// ----------------------------------------------------------------------------- : Parsing
+
+/// Precedence levels for parsing, higher = tighter
+enum Precedence
+{	PREC_ALL
+,	PREC_NEWLINE	// newline ;
+,	PREC_SEQ		// ;
+,	PREC_SET		// :=
+,	PREC_AND		// and or
+,	PREC_CMP		// == != < > <= >=
+,	PREC_ADD		// + -
+,	PREC_MUL		// * / mod
+,	PREC_UNARY		// - not    (unary operators)
+,	PREC_FUN		// [] () .  (function call, member)
+,	PREC_STRING		// +{ }+    (smart string operators)
+,	PREC_NONE
+};
+
+/// Parse an expression
+/** @param input   Read tokens from the input
+ *  @param scrip   Add resulting instructions to the script
+ *  @param minPrec Minimum precedence level for operators
+ *  NOTE: The net stack effect of an expression should be +1
+ */
+void parseExpr(TokenIterator& input, Script& script, Precedence minPrec);
+
+/// Parse an expression, possibly with operators applied. Optionally adds an instruction at the end.
+/** @param input     Read tokens from the input
+ *  @param scrip     Add resulting instructions to the script
+ *  @param minPrec   Minimum precedence level for operators
+ *  @param closeWith Add this instruction at the end
+ *  @param closeWithData Data for the instruction at the end
+ *  NOTE: The net stack effect of an expression should be +1
+ */
+void parseOper(TokenIterator& input, Script& script, Precedence minPrec, InstructionType closeWith = I_NOP, int closeWithData = 0);
+
+ScriptP parse(const String& s) {
+	TokenIterator input(s);
+	ScriptP script(new Script);
+	parseOper(input, *script, PREC_ALL, I_RET);
+	if (input.peek() != TOK_EOF) {
+		throw ScriptParseError(_("end of input"), input.peek().value);
+	} else {
+		return script;
+	}
+}
+
+// Expect a token, throws if it is not found
+void expectToken(TokenIterator& input, const Char* expect) {
+	Token token = input.read();
+	while (token == TOK_NEWLINE) token = input.read(); // skip newlines
+	if (token != expect) {
+		throw ScriptParseError(expect, token.value);
+	}
+}
+
+void parseExpr(TokenIterator& input, Script& script, Precedence minPrec) {
+	// usually loop only once, unless we encounter newlines
+	while (true) {
+		const Token& token = input.read();
+		if (token == _("(")) {
+			// Parentheses = grouping for precedence of expressions
+			parseOper(input, script, PREC_ALL);
+			expectToken(input, _(")"));
+		} else if (token == _("{")) {
+			// {} = function block. Parse a new Script
+			intrusive_ptr<Script> subScript(new Script);
+			parseOper(input, *subScript, PREC_ALL, I_RET);
+			expectToken(input, _("}"));
+			script.addInstruction(I_PUSH_CONST, subScript);
+		} else if (minPrec <= PREC_UNARY && token == _("-")) {
+			parseOper(input, script, PREC_UNARY, I_UNARY, I_NEGATE); // unary negation
+		} else if (token == TOK_NAME) {
+			if (minPrec <= PREC_UNARY && token == _("not")) {
+				parseOper(input, script, PREC_UNARY, I_UNARY, I_NOT); // unary not
+			} else if (token == _("true")) {
+				script.addInstruction(I_PUSH_CONST, scriptTrue); // boolean constant : true
+			} else if (token == _("false")) {
+				script.addInstruction(I_PUSH_CONST, scriptFalse); // boolean constant : false
+			} else if (token == _("if")) {
+				// if AAA then BBB else CCC
+				unsigned int jmpElse, jmpEnd;
+				parseOper(input, script, PREC_SET);						// AAA
+				jmpElse = script.getLabel();							//		jmp_else:
+				script.addInstruction(I_JUMP_IF_NOT, 0xFFFF);			//		jnz lbl_else
+				expectToken(input, _("then"));							// then
+				parseOper(input, script, PREC_SET);						// BBB
+				jmpEnd = script.getLabel();								//		jmp_end:
+				script.addInstruction(I_JUMP, 0xFFFF);					//		jump lbl_end
+				script.comeFrom(jmpElse);								//		lbl_else:
+				if (input.read() == _("else")) {						// else
+					parseOper(input, script, PREC_SET);					// CCC
+				} else {
+					script.addInstruction(I_PUSH_CONST, scriptNil);
+				}
+				script.comeFrom(jmpEnd);								//		lbl_end:
+			} else if (token == _("for")) {
+				unsigned int lblStart;
+				// 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
+					if (name != TOK_NAME) throw ScriptParseError(_("name"), name.value);
+					expectToken(input, _("in"));						// in
+					parseOper(input, script, PREC_SET);					// BBB
+					script.addInstruction(I_UNARY, I_ITERATOR_C);		//		iterator_collection
+					script.addInstruction(I_PUSH_CONST, scriptNil);		//		push nil
+					lblStart = script.getLabel();						//		lbl_start:
+					script.addInstruction(I_LOOP, 0xFFFF);				//		loop
+					expectToken(input, _("do"));						// do
+					script.addInstruction(I_SET_VAR,
+										stringToVariable(name.value));	//		set name
+					script.addInstruction(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_SET);					// BBB
+					expectToken(input, _("to"));						// to
+					parseOper(input, script, PREC_SET);					// CCC
+					script.addInstruction(I_BINARY, I_ITERATOR_R);		//		iterator_range
+					script.addInstruction(I_PUSH_CONST, scriptNil);		//		push nil
+					lblStart = script.getLabel();						//		lbl_start:
+					script.addInstruction(I_LOOP, 0xFFFF);				//		loop
+					expectToken(input, _("do"));						// do
+					script.addInstruction(I_SET_VAR,
+										stringToVariable(name.value));	//		set name
+					script.addInstruction(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:
+				}
+			} else if (token == _("rgb")) {
+				// rgb(r, g, b)
+				expectToken(input, _("("));
+				parseOper(input, script, PREC_ALL); // r
+				expectToken(input, _(","));
+				parseOper(input, script, PREC_ALL); // g
+				expectToken(input, _(","));
+				parseOper(input, script, PREC_ALL); // b
+				expectToken(input, _(")"));
+				script.addInstruction(I_TERNARY, I_RGB);
+			} else {
+				// variable
+				unsigned int var = stringToVariable(token.value);
+				script.addInstruction(I_GET_VAR, var);
+			}
+		} else if (token == TOK_INT) {
+			long l;
+			l = lexical_cast<long>(token.value);
+			//token.value.toLong(l);
+			script.addInstruction(I_PUSH_CONST, toScript(l));
+		} else if (token == TOK_DOUBLE) {
+			double d;
+			d = lexical_cast<double>(token.value);
+			//token.value.toDouble(d);
+			script.addInstruction(I_PUSH_CONST, toScript(d));
+		} else if (token == TOK_STRING) {
+			script.addInstruction(I_PUSH_CONST, toScript(token.value));
+		} else if (token == TOK_NEWLINE) {
+			continue; // ignore
+		} else {
+			throw ScriptParseError(_("Unexpected token '") + token.value + _("'"));
+		}
+		break;
+	}
+}
+
+void parseOper(TokenIterator& input, Script& script, Precedence minPrec, InstructionType closeWith, int closeWithData) {
+	parseExpr(input, script, minPrec); // first argument
+	bool newlines = false; // did we skip any newlines?
+	// read any operators after an expression
+	// EBNF:                    expr = expr | expr oper expr
+	// without left recursion:  expr = expr (oper expr)*
+	while (true) {
+		const Token& token = input.read();
+		bool newlines2 = newlines;
+		newlines = false;
+		if (token == TOK_OPER || token == TOK_NAME) {
+			if (minPrec <= PREC_SEQ && token==_(";")) {
+				Token next = input.peek(1);
+				if (next == TOK_RPAREN || next == TOK_EOF) {
+					// allow ; at end of expression without errors
+					return;
+				}
+				script.addInstruction(I_POP); // discard result of first expression
+				parseOper(input, script, PREC_SET);
+			} else if (minPrec <= PREC_SET && token==_(":=")) {
+				// We made a mistake, the part before the := should be a variable name,
+				// not an expression. Remove that instruction.
+				Instruction instr = script.getInstructions().back();
+				if (instr.instr != I_GET_VAR) {
+					throw ScriptParseError("Can only assign to variables");
+				} else {
+					script.getInstructions().pop_back();
+					parseOper(input, script, PREC_SET,  I_SET_VAR, instr.data);
+				}
+			}
+			else if (minPrec <= PREC_AND    && token==_("and"))   parseOper(input, script, PREC_CMP,   I_BINARY, I_AND);
+			else if (minPrec <= PREC_AND    && token==_("or" ))   parseOper(input, script, PREC_CMP,   I_BINARY, I_OR);
+			else if (minPrec <= PREC_CMP    && token==_("="))     parseOper(input, script, PREC_ADD,   I_BINARY, I_EQ);
+			else if (minPrec <= PREC_CMP    && token==_("=="))    parseOper(input, script, PREC_ADD,   I_BINARY, I_EQ);
+			else if (minPrec <= PREC_CMP    && token==_("!="))    parseOper(input, script, PREC_ADD,   I_BINARY, I_NEQ);
+			else if (minPrec <= PREC_CMP    && token==_("<"))     parseOper(input, script, PREC_ADD,   I_BINARY, I_LT);
+			else if (minPrec <= PREC_CMP    && token==_(">"))     parseOper(input, script, PREC_ADD,   I_BINARY, I_GT);
+			else if (minPrec <= PREC_CMP    && token==_("<="))    parseOper(input, script, PREC_ADD,   I_BINARY, I_LE);
+			else if (minPrec <= PREC_CMP    && token==_(">="))    parseOper(input, script, PREC_ADD,   I_BINARY, I_GE);
+			else if (minPrec <= PREC_ADD    && token==_("+"))     parseOper(input, script, PREC_MUL,   I_BINARY, I_ADD);
+			else if (minPrec <= PREC_ADD    && token==_("-"))     parseOper(input, script, PREC_MUL,   I_BINARY, I_SUB);
+			else if (minPrec <= PREC_MUL    && token==_("*"))     parseOper(input, script, PREC_UNARY, I_BINARY, I_MUL);
+			else if (minPrec <= PREC_MUL    && token==_("/"))     parseOper(input, script, PREC_UNARY, I_BINARY, I_DIV);
+			else if (minPrec <= PREC_MUL    && token==_("mod"))   parseOper(input, script, PREC_UNARY, I_BINARY, I_MOD);
+			else if (minPrec <= PREC_FUN    && token==_(".")) { // get member by name
+				const Token& token = input.read();
+				if (token == TOK_NAME || token == TOK_INT || token == TOK_DOUBLE || token == TOK_STRING) {
+					script.addInstruction(I_MEMBER_C, token.value);
+				} else {
+					throw ScriptParseError(_("name"), input.peek().value);
+				}
+			} else {
+				input.putBack();
+				newlines = newlines2; // remember newlines
+				break; // unknown operator
+			}
+		} else if (token==TOK_LPAREN) {
+			if (minPrec <= PREC_FUN && token==_("(")) {
+				// function call, read arguments
+				vector<int> arguments;
+				Token t = input.peek();
+				while (t != _(")")) {
+					if (input.peek(2) == _(":")) {
+						// name: ...
+						arguments.push_back(stringToVariable(t.value));
+						input.read(); // skip the name
+						input.read(); // and the :
+						parseOper(input, script, PREC_SEQ);
+					} else {
+						// implicit "input" argument
+						arguments.push_back(stringToVariable(_("input")));
+						parseOper(input, script, PREC_SEQ);
+					}
+					t = input.peek();
+					if (t == _(",")) {
+						// Comma separating the arguments
+						input.read();
+						t = input.peek();
+					}
+				}
+				input.read(); // skip the )
+				// generate instruction
+				script.addInstruction(I_CALL, (unsigned int)arguments.size());
+				FOR_EACH(arg,arguments) {
+					script.addInstruction(I_NOP, arg);
+				}
+			} else if (minPrec <= PREC_FUN && token==_("[")) { // get member by expr
+				parseOper(input, script, PREC_ALL, I_BINARY, I_MEMBER);
+				expectToken(input, _("]"));
+			} else if (minPrec <= PREC_STRING && token==_("\"{")) {
+				// for smart strings: "x" {{ e }} "y"
+				parseOper(input, script, PREC_ALL,  I_BINARY, I_ADD);	// e
+				expectToken(input, _("}\""));
+				parseOper(input, script, PREC_NONE, I_BINARY, I_ADD);	// y
+			} else {
+				input.putBack();
+				newlines = newlines2; // remember newlines
+				break; // unknown LPAREN, has to be {
+			}
+		} else if (token == TOK_NEWLINE) {
+			const Token& next = input.peek(1);
+			if (minPrec <= PREC_NEWLINE && (next == TOK_NAME || next == TOK_LPAREN)) {
+				// function as ;
+				script.addInstruction(I_POP);
+				parseOper(input, script, PREC_SET);
+			} else {
+				// skip newlines
+				newlines = true;
+			}
+		} else {
+			input.putBack();
+			newlines = newlines2; // remember newlines
+			break;
+		}
+	}
+	if (newlines) {
+		// we accidentally ate a newline, restore it
+		input.putBack();
+	}
+	// add closing instruction
+	if (closeWith != I_NOP) {
+		script.addInstruction(closeWith, closeWithData);
+	}
+}

src/script/parser.hpp

@@ -0,0 +1,21 @@
+//+----------------------------------------------------------------------------+
+//| Description:  Magic Set Editor - Program to make Magic (tm) cards          |
+//| Copyright:    (C) 2001 - 2006 Twan van Laarhoven                           |
+//| License:      GNU General Public License 2 or later (see file COPYING)     |
+//+----------------------------------------------------------------------------+
+
+#ifndef HEADER_SCRIPT_PARSER
+#define HEADER_SCRIPT_PARSER
+
+// ----------------------------------------------------------------------------- : Includes
+
+#include <util/prec.hpp>
+#include <script/script.hpp>
+
+// ----------------------------------------------------------------------------- : Parser
+
+// Parse a String to a Script
+ScriptP parse(const String& s);
+
+// ----------------------------------------------------------------------------- : EOF
+#endif

src/script/script.cpp

@@ -0,0 +1,165 @@
+//+----------------------------------------------------------------------------+
+//| Description:  Magic Set Editor - Program to make Magic (tm) cards          |
+//| Copyright:    (C) 2001 - 2006 Twan van Laarhoven                           |
+//| License:      GNU General Public License 2 or later (see file COPYING)     |
+//+----------------------------------------------------------------------------+
+
+// ----------------------------------------------------------------------------- : Includes
+
+#include <script/script.hpp>
+#include <script/context.hpp>
+#include <boost/lexical_cast.hpp>
+
+// ----------------------------------------------------------------------------- : Variables
+
+typedef map<string, unsigned int> Variables;
+Variables variables;
+DECLARE_TYPEOF(Variables);
+
+/// Return a unique name for a variable to allow for faster loopups
+unsigned int stringToVariable(const String& s) {
+	map<string, unsigned int>::iterator it = variables.find(s);
+	if (it == variables.end()) {
+		unsigned int v = (unsigned int)variables.size();
+		variables.insert(make_pair(s,v));
+		return v;
+	} else {
+		return it->second;
+	}
+}
+
+/// Get the name of a vaiable
+/** Warning: this function is slow, it should only be used for error messages and such.
+ */
+String variableToString(unsigned int v) {
+	FOR_EACH(vi, variables) {
+		if (vi.second == v) return vi.first;
+	}
+	throw "Variable not found: " + lexical_cast<String>(v);
+}
+
+// ----------------------------------------------------------------------------- : Script
+
+ScriptType Script::type() const {
+	return SCRIPT_SCRIPT_FUN;
+}
+String Script::typeName() const {
+	return "function";
+}
+ScriptValueP Script::eval(Context& ctx) const {
+	return ctx.eval(*this);
+}
+ScriptValueP Script::dependencies(Context& ctx, const Dependency& dep) const {
+	return ctx.dependencies(dep, *this);
+}
+	
+void Script::addInstruction(InstructionType t) {
+	//if (t == I_MEMBER_V && !instructions.empty() && instructions.back().instr == I_PUSH_CONST) {
+	//	// optimize: push x ; member_v -->  member x
+	//	instructions.back().instr = I_MEMBER;
+	//} else {
+	Instruction i = {t, 0};
+	instructions.push_back(i);
+	//}
+}
+void Script::addInstruction(InstructionType t, unsigned int d) {
+	Instruction i = {t, d};
+	instructions.push_back(i);
+}
+void Script::addInstruction(InstructionType t, const ScriptValueP& c) {
+	constants.push_back(c);
+	Instruction i = {t, (unsigned int)constants.size() - 1};
+	instructions.push_back(i);
+}
+void Script::addInstruction(InstructionType t, const String& s) {
+	constants.push_back(toScript(s));
+	Instruction i = {t, (unsigned int)constants.size() - 1};
+	instructions.push_back(i);
+}
+
+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).data = (unsigned int)instructions.size();
+}
+
+unsigned int Script::getLabel() const {
+	return (unsigned int)instructions.size();
+}
+
+DECLARE_TYPEOF_COLLECTION(Instruction);
+
+String Script::dumpScript() const {
+	String ret;
+	int pos = 0;
+	FOR_EACH_CONST(i, instructions) {
+		ret += dumpInstr(pos++, i) + "\n";
+	}
+	return ret;
+}
+
+String Script::dumpInstr(unsigned int pos, Instruction i) const {
+	String ret = lexical_cast<String>(pos) + ":\t";
+	// instruction
+	switch (i.instr) {
+		case I_NOP:			ret += "nop";		break;
+		case I_PUSH_CONST:	ret += "push";		break;
+		case I_POP:			ret += "pop";		break;
+		case I_JUMP:		ret += "jump";		break;
+		case I_JUMP_IF_NOT:	ret += "jnz";		break;
+		case I_GET_VAR:		ret += "get";		break;
+		case I_SET_VAR:		ret += "set";		break;
+		case I_MEMBER_C:	ret += "member_c";	break;
+		case I_LOOP:		ret += "loop";		break;
+		case I_CALL:		ret += "call";		break;
+		case I_RET:			ret += "ret";		break;
+		case I_UNARY:		ret += "unary\t";
+			switch (i.instr1) {
+				case I_ITERATOR_C:	ret += "iterator_c";break;
+				case I_NEGATE:		ret += "negate";	break;
+				case I_NOT:			ret += "not";		break;
+			}
+			break;
+		case I_BINARY:		ret += "binary\t";
+			switch (i.instr2) {
+				case I_ITERATOR_R:	ret += "iterator_r";break;
+				case I_MEMBER:		ret += "member";	break;
+				case I_ADD:			ret += "+";			break;
+				case I_SUB:			ret += "-";			break;
+				case I_MUL:			ret += "*";			break;
+				case I_DIV:			ret += "/";			break;
+				case I_MOD:			ret += "*";			break;
+				case I_AND:			ret += "and";		break;
+				case I_OR:			ret += "or";		break;
+				case I_EQ:			ret += "==";		break;
+				case I_NEQ:			ret += "!=";		break;
+				case I_LT:			ret += "<";			break;
+				case I_GT:			ret += ">";			break;
+				case I_LE:			ret += "<=";		break;
+				case I_GE:			ret += ">=";		break;
+			}
+			break;
+		case I_TERNARY:		ret += "ternary\t";
+			switch (i.instr3) {
+				case I_RGB:			ret += "rgb";		break;
+			}
+			break;
+	}
+	// arg
+	switch (i.instr) {
+		case I_PUSH_CONST: case I_MEMBER_C:							// const
+			ret += "\t" + (String)*constants[i.data];
+			ret += "\t(" + constants[i.data]->typeName();
+			ret += ", #" + lexical_cast<String>(i.data) + ")";
+			break;
+		case I_JUMP: case I_JUMP_IF_NOT: case I_LOOP: case I_CALL:	// int
+			ret += "\t" + lexical_cast<String>(i.data);
+			break;
+		case I_GET_VAR: case I_SET_VAR: case I_NOP:					// variable
+			ret += "\t" + variableToString(i.data) + "\t$" + lexical_cast<String>(i.data);
+			break;
+	}
+	return ret;
+}
+

src/script/script.hpp

@@ -0,0 +1,155 @@
+//+----------------------------------------------------------------------------+
+//| Description:  Magic Set Editor - Program to make Magic (tm) cards          |
+//| Copyright:    (C) 2001 - 2006 Twan van Laarhoven                           |
+//| License:      GNU General Public License 2 or later (see file COPYING)     |
+//+----------------------------------------------------------------------------+
+
+#ifndef HEADER_SCRIPT_SCRIPT
+#define HEADER_SCRIPT_SCRIPT
+
+// ----------------------------------------------------------------------------- : Includes
+
+#include <util/prec.hpp>
+#include <script/value.hpp>
+
+DECLARE_POINTER_TYPE(Script);
+
+// ----------------------------------------------------------------------------- : Instructions
+
+/// A type of instruction to be performed in a script
+/** The reason for the negative values is that the compiler (at least MSVC) considers the bitfield signed
+ */
+enum InstructionType
+	// Basic
+{	I_NOP			= 0  ///< no operation, used as placeholder for extra data values
+,	I_PUSH_CONST	= 1  ///< arg = value : push a constant onto the stack
+,	I_POP			= 2  ///< pop the top value from the stack (used for ; operator)
+,	I_JUMP			= 3  ///< arg = int   : move the instruction pointer to the given position
+,	I_JUMP_IF_NOT	= 4  ///< arg = int   : move the instruction pointer if the top of the stack is false
+	// Variables
+,	I_GET_VAR		= 5  ///< arg = int   : find a variable, push its value onto the stack, it is an error if the variable is not found
+,	I_SET_VAR		= 6  ///< arg = int   : assign the top value from the stack to a variable (doesn't pop)
+	// Objects
+,	I_MEMBER_C		= 7  ///< arg = name  : finds a member of the top of the stack replaces the top of the stack with the member
+,	I_LOOP			= -8 ///< arg = int   : 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!
+	// Functions
+,	I_CALL			= -7 ///< arg = int, int+ : 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_RET			= -6 ///< return from the current function
+	// Simple instructions
+,	I_UNARY			= -5 ///< pop 1 value,  apply a function, push the result
+,	I_BINARY		= -4 ///< pop 2 values, apply a function, push the result
+,	I_TERNARY		= -3 ///< pop 3 values, apply a function, push the result
+};
+
+/// Types of unary instructions (taking one argument from the stack)
+enum UnaryInstructionType
+{	I_ITERATOR_C		///< Make an iterator for a collection
+,	I_NEGATE
+,	I_NOT
+};
+
+/// Types of binary instructions (taking two arguments from the stack)
+enum BinaryInstructionType
+{	I_ITERATOR_R	///< Make an iterator for a range (two integers)
+,	I_MEMBER		///< Member of an object
+// Arithmatic
+,	I_ADD			///< add     
+,	I_SUB			///< subtract
+,	I_MUL			///< multiply
+,	I_DIV			///< divide  
+,	I_MOD			///< modulus
+// Logical
+,	I_AND			///< logical and			
+,	I_OR			///< logical or
+// Comparison
+,	I_EQ			///< operator ==
+,	I_NEQ			///< operator !=
+,	I_LT			///< operator <
+,	I_GT			///< operator >
+,	I_LE			///< operator <=
+,	I_GE			///< operator >=
+};
+
+/// Types of ternary instructions (taking three arguments from the stack)
+enum TernaryInstructionType
+{	I_RGB			///< pop r,g,b, push a color value
+};
+
+/// An instruction in a script, consists of the opcode and data
+/** If the opcode is one of I_UNARY,I_BINARY,I_TERNARY,
+ *  Then the instr? member gives the actual instruction to perform
+ */
+struct Instruction {
+	InstructionType instr : 4;
+	union {
+		unsigned int			data   : 28;
+		UnaryInstructionType	instr1 : 28;
+		BinaryInstructionType	instr2 : 28;
+		TernaryInstructionType	instr3 : 28;
+	};
+};
+
+// ----------------------------------------------------------------------------- : Variables
+
+/// Return a unique name for a variable to allow for faster loopups
+unsigned int stringToVariable(const String& s);
+
+/// Get the name of a vaiable
+/** Warning: this function is slow, it should only be used for error messages and such.
+ */
+String variableToString(unsigned int v);
+
+// ----------------------------------------------------------------------------- : Script
+
+/// A script that can be executed
+/** Represent a function that returns a single value.
+ *  The script is itself a ScriptValue
+ */
+class Script : public ScriptValue {
+  public:
+	/// Set the script to be executed
+	//void setScript(const String& script);
+	
+	virtual ScriptType type() const;
+	virtual String typeName() const;
+	virtual ScriptValueP eval(Context& ctx) const;
+	virtual ScriptValueP dependencies(Context& ctx, const Dependency&) const;
+	
+	/// Add an instruction with no data
+	void addInstruction(InstructionType t);
+	/// Add an instruction with integer data
+	void addInstruction(InstructionType t, unsigned int d);
+	/// Add an instruction with constant data
+	void addInstruction(InstructionType t, const ScriptValueP& c);
+	/// Add an instruction with string data
+	void addInstruction(InstructionType t, const String& s);
+	
+	/// Update an instruction to point to the current position
+	/** The instruction at pos must be a jumping instruction, it is changed so the current position
+	 *  'comes from' pos (in addition to other control flow).
+	 *  The position must be a label just before the instruction to be updated.
+	 */
+	void comeFrom(unsigned int pos);
+	/// Get the current instruction position
+	unsigned int getLabel() const;
+	
+	/// Get access to the vector of instructions
+	inline vector<Instruction>& getInstructions() { return instructions; }
+	
+	/// Output the instructions in a human readable format
+	String dumpScript() const;
+	/// Output an instruction in a human readable format
+	String dumpInstr(unsigned int pos, Instruction i) const;
+	
+  private:
+	/// Data of the instructions that make up this script
+	vector<Instruction>  instructions;
+	/// Constant values that can be referred to from the script
+	vector<ScriptValueP> constants;
+	
+	friend class Context;
+};
+
+// ----------------------------------------------------------------------------- : EOF
+#endif

src/script/value.cpp

@@ -0,0 +1,161 @@
+//+----------------------------------------------------------------------------+
+//| Description:  Magic Set Editor - Program to make Magic (tm) cards          |
+//| Copyright:    (C) 2001 - 2006 Twan van Laarhoven                           |
+//| License:      GNU General Public License 2 or later (see file COPYING)     |
+//+----------------------------------------------------------------------------+
+
+// ----------------------------------------------------------------------------- : Includes
+
+#include <script/value.hpp>
+#include <util/error.hpp>
+#include <boost/lexical_cast.hpp> //%%
+#include <boost/pool/singleton_pool.hpp>
+
+// ----------------------------------------------------------------------------- : ScriptValue
+// Base cases
+
+ScriptValue::operator String() const { return "[[" + typeName() + "]]"; }
+ScriptValue::operator int()    const { throw ScriptError("Can't convert from "+typeName()+" to integer number"); }
+ScriptValue::operator double() const { throw ScriptError("Can't convert from "+typeName()+" to real number"   ); }
+ScriptValue::operator Color()  const { throw ScriptError("Can't convert from "+typeName()+" to color"         ); }
+ScriptValueP ScriptValue::eval(Context&) const
+                                     { throw ScriptError("Can't convert from "+typeName()+" to function"      ); }
+ScriptValueP ScriptValue::getMember(const String& name) const
+                                     { throw (typeName() + " has no member '" + name + "'"); }
+ScriptValueP ScriptValue::next()               { throw InternalError("Can't convert from "+typeName()+" to iterator"); }
+ScriptValueP ScriptValue::makeIterator() const { throw ScriptError("Can't convert from "+typeName()+" to collection"); }
+
+void ScriptValue::signalDependent(Context&, const Dependency&, const String& name) {}
+ScriptValueP ScriptValue::dependencies(   Context&, const Dependency&) const { return scriptNil; }
+
+
+// ----------------------------------------------------------------------------- : Iterators
+
+ScriptType ScriptIterator::type() const { return SCRIPT_OBJECT; }
+String ScriptIterator::typeName() const { return "iterator"; }
+
+// Iterator over a range of integers
+class ScriptRangeIterator : public ScriptIterator {
+  public:
+	// Construct a range iterator with the given bounds (inclusive)
+	ScriptRangeIterator(int start, int end)
+		: pos(start), end(end) {}
+	virtual ScriptValueP next() {
+		if (pos <= end) {
+			return toScript(pos++);
+		} else {
+			return ScriptValueP();
+		}
+	}
+  private:
+	int pos, end;
+};
+
+ScriptValueP rangeIterator(int start, int end) {
+	return new_intrusive2<ScriptRangeIterator>(start, end);
+}
+
+// ----------------------------------------------------------------------------- : Integers
+
+// Integer values
+class ScriptInt : public ScriptValue {
+  public:
+	ScriptInt(int v) : value(v) {}
+	virtual ScriptType type() const { return SCRIPT_INT; }
+	virtual String typeName() const { return "integer number"; }
+	virtual operator String() const { return lexical_cast<String>(value); }
+	virtual operator double() const { return value; }
+	virtual operator int()    const { return value; }
+  protected:
+	virtual void destroy() {
+		boost::singleton_pool<ScriptValue, sizeof(ScriptInt)>::free(this);
+	}
+  private:
+	int value;
+};
+
+ScriptValueP toScript(int v) {
+//	return new_intrusive1<ScriptInt>(v);
+	return ScriptValueP(
+			new(boost::singleton_pool<ScriptValue, sizeof(ScriptInt)>::malloc())
+				ScriptInt(v));
+}
+
+// use integers to represent true/false
+ScriptValueP scriptTrue  = toScript((int)true);
+ScriptValueP scriptFalse = toScript((int)false);
+
+
+// ----------------------------------------------------------------------------- : Doubles
+
+// Double values
+class ScriptDouble : public ScriptValue {
+  public:
+	ScriptDouble(double v) : value(v) {}
+	virtual ScriptType type() const { return SCRIPT_DOUBLE; }
+	virtual String typeName() const { return "real number"; }
+	virtual operator String() const { return lexical_cast<String>(value); }
+	virtual operator double() const { return value; }
+	virtual operator int()    const { return (int)value; }
+  private:
+	double value;
+};
+
+ScriptValueP toScript(double v) {
+	return new_intrusive1<ScriptDouble>(v);
+}
+
+// ----------------------------------------------------------------------------- : String type
+
+// String values
+class ScriptString : public ScriptValue {
+  public:
+	ScriptString(const String& v) : value(v) {}
+	virtual ScriptType type() const { return SCRIPT_STRING; }
+	virtual String typeName() const { return "string"; }
+	virtual operator String() const { return value; }
+	virtual operator double() const { return lexical_cast<double>(value); }
+	virtual operator int()    const { return lexical_cast<int>(value); }
+  private:
+	String value;
+};
+
+ScriptValueP toScript(const String& v) {
+	return new_intrusive1<ScriptString>(v);
+}
+
+
+// ----------------------------------------------------------------------------- : Color
+
+// Color values
+class ScriptColor : public ScriptValue {
+  public:
+	ScriptColor(const Color& v) : value(v) {}
+	virtual ScriptType type() const { return SCRIPT_COLOR; }
+	virtual String typeName() const { return "color"; }
+  private:
+	Color value;
+};
+
+ScriptValueP toScript(const Color& v) {
+	return new_intrusive1<ScriptColor>(v);
+}
+
+
+// ----------------------------------------------------------------------------- : Nil type
+
+// the nil object
+class ScriptNil : public ScriptValue {
+  public:
+	virtual ScriptType type() const { return SCRIPT_NIL; }
+	virtual String typeName() const { return "nil"; }
+	virtual operator String() const { return ""; }
+	virtual operator double() const { return 0.0; }
+	virtual operator int()    const { return 0; }
+};
+
+/// The preallocated nil value
+ScriptValueP scriptNil(new ScriptNil);
+
+
+// ----------------------------------------------------------------------------- : EOF

src/script/value.hpp

@@ -0,0 +1,260 @@
+//+----------------------------------------------------------------------------+
+//| Description:  Magic Set Editor - Program to make Magic (tm) cards          |
+//| Copyright:    (C) 2001 - 2006 Twan van Laarhoven                           |
+//| License:      GNU General Public License 2 or later (see file COPYING)     |
+//+----------------------------------------------------------------------------+
+
+#ifndef HEADER_SCRIPT_VALUE
+#define HEADER_SCRIPT_VALUE
+
+// ----------------------------------------------------------------------------- : Includes
+
+#include <util/prec.hpp>
+#include <boost/intrusive_ptr.hpp>
+#include <boost/lexical_cast.hpp> //%%
+
+//#ifndef WINVER
+//#define WINVER 0x0501
+//#endif
+//#include <winresrc.h>
+//#include <windef.h>
+//#include <winbase.h> // Interlocked*crement
+#include <windows.h>
+#define TokenType TokenType_
+
+extern "C" {
+   LONG  __cdecl _InterlockedIncrement(LONG volatile *Addend);
+   LONG  __cdecl _InterlockedDecrement(LONG volatile *Addend);
+}
+#pragma intrinsic (_InterlockedIncrement)
+#define InterlockedIncrement _InterlockedIncrement
+#pragma intrinsic (_InterlockedDecrement)
+#define InterlockedDecrement _InterlockedDecrement
+
+//long __declspec(dllimport) __stdcall InterlockedDecrement(long volatile* Addend);
+//long __declspec(dllimport) __stdcall InterlockedIncrement(long volatile* Addend);
+//#pragma intrinsic(_InterlockedIncrement)
+//#pragma intrinsic( _InterlockedDecrement )
+
+class Context;
+class Dependency;
+
+// ----------------------------------------------------------------------------- : ScriptValue
+
+//DECLARE_POINTER_TYPE(ScriptValue);
+class ScriptValue;
+typedef boost::intrusive_ptr<ScriptValue> ScriptValueP;
+
+enum ScriptType
+{	SCRIPT_NIL
+,	SCRIPT_INT
+,	SCRIPT_DOUBLE
+,	SCRIPT_STRING
+,	SCRIPT_COLOR
+,	SCRIPT_BUILDIN_FUN
+,	SCRIPT_SCRIPT_FUN
+,	SCRIPT_OBJECT
+,	SCRIPT_DUMMY
+};
+
+/// A value that can be handled by the scripting engine.
+/// Actual values are derived types
+class ScriptValue {
+  public:
+	inline ScriptValue() : refCount(0) {}
+	virtual ~ScriptValue() {}
+	
+	/// Information on the type of this value
+	virtual ScriptType type() const = 0;
+	/// Name of the type of value
+	virtual String typeName() const = 0;
+	
+	/// Convert this value to a string
+	virtual operator String() const;
+	/// Convert this value to a double
+	virtual operator double() const;
+	/// Convert this value to an integer
+	virtual operator int()    const;
+	/// Convert this value to a color
+	virtual operator Color()  const;
+		
+	/// Get a member variable from this value
+	virtual ScriptValueP getMember(const String& name) const;
+	
+	/// Evaluate this value (if it is a function)
+	virtual ScriptValueP eval(Context&) const;
+	
+	/// Return an iterator for the current collection, an iterator is a value that has next()
+	virtual ScriptValueP makeIterator() const;
+	/// Return the next item for this iterator, or ScriptValueP() if there is no such item
+	virtual ScriptValueP next();
+	
+	/// Signal that a script depends on a member of this value
+	virtual void signalDependent(Context&, const Dependency&, const String& name);
+	/// Mark the scripts that this function depends on
+	/** Return value is an abstract version of the return value of eval */
+	virtual ScriptValueP dependencies(Context&, const Dependency&) const;
+	
+  protected:
+	/// Delete this object
+	virtual void destroy() {
+		delete this;
+	}
+  private:
+	volatile LONG refCount;
+	friend void intrusive_ptr_add_ref(ScriptValue*);
+	friend void intrusive_ptr_release(ScriptValue*);
+};
+
+inline void intrusive_ptr_add_ref(ScriptValue* p) {
+	//p->refCount += 1;
+	InterlockedIncrement(&p->refCount);
+}
+inline void intrusive_ptr_release(ScriptValue* p) {
+	if (InterlockedDecrement(&p->refCount) == 0) {
+	//if (--p->refCount == 0) {
+		p->destroy();
+	}
+}
+
+extern ScriptValueP scriptNil;   ///< The preallocated nil value
+extern ScriptValueP scriptTrue;  ///< The preallocated true value
+extern ScriptValueP scriptFalse; ///< The preallocated false value
+
+
+// ----------------------------------------------------------------------------- : Iterators
+
+// Iterator over a collection
+struct ScriptIterator : public ScriptValue {
+	virtual ScriptType type() const;// { return SCRIPT_OBJECT; }
+	virtual String typeName() const;// { return "iterator"; }
+	
+	/// Return the next item for this iterator, or ScriptValueP() if there is no such item
+	virtual ScriptValueP next() = 0;
+};
+
+// make an iterator over a range
+ScriptValueP rangeIterator(int start, int end);
+
+// ----------------------------------------------------------------------------- : Collections
+
+// Iterator over a collection
+template <typename Collection>
+class ScriptCollectionIterator : public ScriptIterator {
+  public:	
+	ScriptCollectionIterator(const Collection* col) : pos(0), col(col) {}
+	virtual ScriptValueP next() {
+		if (pos < col->size()) {
+			return toScript(col->at(pos++));
+		} else {
+			return ScriptValueP();
+		}
+	}
+  private:
+	size_t pos;
+	const Collection* col;
+};
+
+/// Script value containing a collection
+template <typename Collection>
+class ScriptCollection : public ScriptValue {
+  public:
+	inline ScriptCollection(const Collection* v) : value(v) {}
+	virtual ScriptType type() const { return SCRIPT_OBJECT; }
+	virtual String typeName() const { return "collection"; }
+	virtual ScriptValueP getMember(const String& name) const {
+		int index = lexical_cast<int>(name);
+		return toScript(value->at(index));
+	}
+	virtual ScriptValueP makeIterator() const {
+		return new_intrusive1<ScriptCollectionIterator<Collection> >(value);
+	}
+  private:
+	/// Store a pointer to a collection, collections are only ever used for structures owned outside the script
+	const Collection* value;
+};
+
+// ----------------------------------------------------------------------------- : Objects
+
+/// Script value containing an object (pointer)
+template <typename T>
+class ScriptObject : public ScriptValue {
+  public:
+	inline ScriptObject(const shared_ptr<T>& v) : value(v) {}
+	virtual ScriptType type() const { return SCRIPT_OBJECT; }
+	virtual String typeName() const { return "object"; }
+	virtual ScriptValueP getMember(const String& name) const {
+		GetMember gm(name);
+		gm.handle(*value);
+		if (gm.result()) return gm.result();
+		else             throw  ScriptError(_("Object has no member '") + name + _("'"));
+	}
+  private:
+	shared_ptr<T> value; ///< The object
+};
+
+// ----------------------------------------------------------------------------- : Creating
+
+/// Convert a value to a script value
+ScriptValueP toScript(int           v);
+ScriptValueP toScript(double        v);
+ScriptValueP toScript(const String& v);
+ScriptValueP toScript(const Color&  v);
+inline ScriptValueP toScript(bool                 v) { return v ? scriptTrue : scriptFalse; }
+template <typename T>
+inline ScriptValueP toScript(const vector<T>*     v) { return new_intrusive1<ScriptCollection<vector<T> > >(v); }
+template <typename T>
+inline ScriptValueP toScript(const shared_ptr<T>& v) { return new_intrusive1<ScriptObject<T> >(v); }
+
+
+// ----------------------------------------------------------------------------- : Buildin functions
+
+/// Macro to declare a new script function
+/** Usage:
+ *  @code
+ *   SCRIPT_FUNCTION(my_function) {
+ *      // function code goes here
+ *   }
+ *  @endcode
+ *  This declares a value 'script_my_function' which can be added as a variable to a context
+ *  using:
+ *  @code
+ *   extern ScriptValueP script_my_function;
+ *   context.setVariable("my_function", script_my_function);
+ *  @endcode
+ */
+#define SCRIPT_FUNCTION(name) SCRIPT_FUNCTION_AUX(name,virtual)
+
+/// Macro to declare a new script function with custom dependency handling
+#define SCRIPT_FUNCTION_DEP(name) SCRIPT_FUNCTION_AUX(name,virtual) //TODO
+
+// helper for SCRIPT_FUNCTION and SCRIPT_FUNCTION_DEP
+#define SCRIPT_FUNCTION_AUX(name,dep)							\
+		class ScriptBuildin_##name : public ScriptValue {		\
+			dep													\
+			/* virtual */ ScriptType type() const				\
+				{ return SCRIPT_BUILDIN_FUN; }					\
+			virtual String typeName() const						\
+				{ return _("build in function '") _(#name) _("'"); }	\
+			virtual ScriptValueP eval(Context&) const;			\
+		};														\
+		ScriptValueP script_##name(new ScriptBuildin_##name);	\
+		ScriptValueP ScriptBuildin_##name::eval(Context& ctx) const
+
+/// Retrieve a parameter to a SCRIPT_FUNCTION with the given name and type
+/** Usage:
+ *  @code
+ *   SCRIPT_FUNCTION(my_function) {
+ *      SCRIPT_PARAM(String, my_string_param);
+ *   }
+ *  @endcode
+ *  Throws an error if the parameter is not found.
+ */
+#define SCRIPT_PARAM(Type, name)								\
+		Type name = *ctx.getVariable(_(#name))
+
+/// Return a value from a SCRIPT_FUNCTION
+#define SCRIPT_RETURN(value) return toScript(value)
+
+// ----------------------------------------------------------------------------- : EOF
+#endif

src/util/io/get_member.cpp

@@ -0,0 +1,22 @@
+//+----------------------------------------------------------------------------+
+//| Description:  Magic Set Editor - Program to make Magic (tm) cards          |
+//| Copyright:    (C) 2001 - 2006 Twan van Laarhoven                           |
+//| License:      GNU General Public License 2 or later (see file COPYING)     |
+//+----------------------------------------------------------------------------+
+
+// ----------------------------------------------------------------------------- : Includes
+
+#include <util/io/get_member.hpp>
+#include <script/value.hpp>
+
+// ----------------------------------------------------------------------------- : GetMember
+
+GetMember::GetMember(const String& name)
+	: targetName(name)
+{}
+
+void GetMember::store(const String&       v) { value = toScript(v); }
+void GetMember::store(const int           v) { value = toScript(v); }
+void GetMember::store(const unsigned int  v) { value = toScript((int)v); }
+void GetMember::store(const double        v) { value = toScript(v); }
+void GetMember::store(const bool          v) { value = toScript(v); }

src/util/io/get_member.hpp

@@ -0,0 +1,100 @@
+//+----------------------------------------------------------------------------+
+//| Description:  Magic Set Editor - Program to make Magic (tm) cards          |
+//| Copyright:    (C) 2001 - 2006 Twan van Laarhoven                           |
+//| License:      GNU General Public License 2 or later (see file COPYING)     |
+//+----------------------------------------------------------------------------+
+
+#ifndef HEADER_UTIL_IO_GET_MEMBER
+#define HEADER_UTIL_IO_GET_MEMBER
+
+// ----------------------------------------------------------------------------- : Includes
+
+#include <util/prec.hpp>
+
+class ScriptValue;
+typedef boost::intrusive_ptr<ScriptValue> ScriptValueP;
+inline void intrusive_ptr_add_ref(ScriptValue* p);
+inline void intrusive_ptr_release(ScriptValue* p);
+
+// ----------------------------------------------------------------------------- : GetMember
+
+/// Find a member with a specific name using reflection
+/** The member is wrapped in a ScriptValue */
+class GetMember {
+  public:
+	/// Construct a member getter that looks for the given name
+	GetMember(const String& name);
+	
+	/// Tell the reflection code we are not reading
+	inline bool reading() const { return false; }
+	
+	/// The result, or scriptNil if the member was not found
+	inline ScriptValueP result() { return value; } 
+	
+	// --------------------------------------------------- : Handling objects
+	
+	/// Handle an object: we are done if the name matches
+	template <typename T>
+	void handle(const Char* name, const T& object) {
+		if (!value && name == targetName) store(object);
+	}
+	template <typename T>
+	void handle(const T&);
+	
+	/// Store something in the return value
+	void store(const String&       v);
+	void store(const int           v);
+	void store(const unsigned int  v);
+	void store(const double        v);
+	void store(const bool          v);
+	/// Store a vector in the return value
+	template <typename T> void store(const vector<T>& vector) {
+		value = toScript(&vector);
+	}
+	/// Store a shared_ptr in the return value
+	template <typename T> void store(const shared_ptr<T>& pointer) {
+		value = toScript(pointer);
+	}
+	
+  private:
+	const String& targetName;	///< The name we are looking for
+	ScriptValueP  value;		///< The value we found (if any)
+};
+
+// ----------------------------------------------------------------------------- : Reflection
+
+/// Implement reflection as used by GetMember
+#define REFLECT_OBJECT_GET_MEMBER(Cls)							\
+	template<> void GetMember::handle<Cls>(const Cls& object) {	\
+		const_cast<Cls&>(object).reflect(*this);				\
+	}
+
+// ----------------------------------------------------------------------------- : Reflection for enumerations
+
+/// Implement enum reflection as used by Writer
+#define REFLECT_ENUM_WRITER(Enum)								\
+	template<> void Writer::handle<Enum>(const Enum& enum_) {	\
+		EnumGetMember gm(*this);								\
+		reflect_ ## Enum(const_cast<Enum&>(enum_), gm);			\
+	}
+
+/// 'Tag' to be used when reflecting enumerations for GetMember
+class EnumGetMember {
+  public:
+	inline EnumGetMember(GetMember& getMember)
+		: getMember(getMember) {}
+	
+	/// Handle a possible value for the enum, if the name matches the name in the input
+	template <typename Enum>
+	inline void handle(const Char* name, Enum value, Enum enum_) {
+		if (enum_ == value) {
+			writer.store(name);
+		}
+	}
+	
+  private:
+	GetMember& getMember;  ///< The writer to write output to
+};
+
+// ----------------------------------------------------------------------------- : EOF
+#endif