5 files changed, 83 insertions, 12 deletions

diff --git a/src/control.cc b/src/control.cc
index d0b96a1..5b7e1b1 100644
--- a/src/control.cc
+++ b/src/control.cc
@@ -149,12 +149,21 @@ AbstractNode *ControlModule::evaluate(const Context*, const ModuleInstantiation
 
 	if (type == IF)
 	{
-		if (inst->argvalues.size() > 0 && inst->argvalues[0].type == Value::BOOL && inst->argvalues[0].b)
-			foreach (ModuleInstantiation *v, inst->children) {
-				AbstractNode *n = v->evaluate(inst->ctx);
+		const IfElseModuleInstantiation *ifelse = dynamic_cast<const IfElseModuleInstantiation*>(inst);
+		if (ifelse->argvalues.size() > 0 && ifelse->argvalues[0].type == Value::BOOL && ifelse->argvalues[0].b) {
+			foreach (ModuleInstantiation *v, ifelse->children) {
+				AbstractNode *n = v->evaluate(ifelse->ctx);
 				if (n != NULL)
 					node->children.append(n);
 			}
+		}
+		else {
+			foreach (ModuleInstantiation *v, ifelse->else_children) {
+				AbstractNode *n = v->evaluate(ifelse->ctx);
+				if (n != NULL)
+					node->children.append(n);
+			}
+		}
 	}
 
 	return node;
diff --git a/src/lexer.l b/src/lexer.l
index b051a5d..5a5c0e9 100644
--- a/src/lexer.l
+++ b/src/lexer.l
@@ -96,6 +96,8 @@ extern const char *parser_source_path;
 
 "module"	return TOK_MODULE;
 "function"	return TOK_FUNCTION;
+"if"		return TOK_IF;
+"else"		return TOK_ELSE;
 
 "true"		return TOK_TRUE;
 "false"		return TOK_FALSE;
diff --git a/src/module.cc b/src/module.cc
index 51d191e..c165131 100644
--- a/src/module.cc
+++ b/src/module.cc
@@ -61,6 +61,12 @@ ModuleInstantiation::~ModuleInstantiation()
 		delete v;
 }
 
+IfElseModuleInstantiation::~IfElseModuleInstantiation()
+{
+	foreach (ModuleInstantiation *v, else_children)
+		delete v;
+}
+
 QString ModuleInstantiation::dump(QString indent) const
 {
 	QString text = indent;
diff --git a/src/module.h b/src/module.h
index 35cc872..20ea1af 100644
--- a/src/module.h
+++ b/src/module.h
@@ -22,12 +22,19 @@ public:
 	const class Context *ctx;
 
 	ModuleInstantiation() : tag_root(false), tag_highlight(false), tag_background(false), ctx(NULL) { }
-	~ModuleInstantiation();
+	virtual ~ModuleInstantiation();
 
 	QString dump(QString indent) const;
 	class AbstractNode *evaluate(const Context *ctx) const;
 };
 
+class IfElseModuleInstantiation : public ModuleInstantiation {
+public:
+	virtual ~IfElseModuleInstantiation();
+
+	QVector<ModuleInstantiation*> else_children;
+};
+
 class AbstractModule
 {
 public:
diff --git a/src/parser.y b/src/parser.y
index 7bee0c1..a0e4ac9 100644
--- a/src/parser.y
+++ b/src/parser.y
@@ -62,12 +62,15 @@ public:
 	class Value *value;
 	class Expression *expr;
 	class ModuleInstantiation *inst;
+	class IfElseModuleInstantiation *ifelse;
 	class ArgContainer *arg;
 	class ArgsContainer *args;
 }
 
 %token TOK_MODULE
 %token TOK_FUNCTION
+%token TOK_IF
+%token TOK_ELSE
 
 %token <text> TOK_ID
 %token <text> TOK_STRING
@@ -96,6 +99,9 @@ public:
 %type <expr> vector_expr
 
 %type <inst> module_instantiation
+%type <ifelse> if_statement
+%type <ifelse> ifelse_statement
+%type <inst> children_instantiation
 %type <inst> module_instantiation_list
 %type <inst> single_module_instantiation
 
@@ -161,29 +167,70 @@ statement:
 		delete $4;
 	} ';' ;
 
-module_instantiation:
-	single_module_instantiation ';' {
+/* Will return a dummy parent node with zero or more children */
+children_instantiation:
+	module_instantiation {
+		$$ = new ModuleInstantiation();
+		if ($1) {
+			$$->children.append($1);
+		} else {
+			delete $1;
+		}
+	} |
+	'{' module_instantiation_list '}' {
+		$$ = $2;
+	} ;
+
+if_statement:
+	TOK_IF '(' expr ')' children_instantiation {
+		$$ = new IfElseModuleInstantiation();
+		$$->modname = "if";
+		$$->argnames.append(QString());
+		$$->argexpr.append($3);
+
+		if ($$) {
+			$$->children = $5->children;
+		} else {
+			for (int i = 0; i < $5->children.count(); i++)
+				delete $5->children[i];
+		}
+		$5->children.clear();
+		delete $5;
+	} ;
+
+ifelse_statement:
+	if_statement {
 		$$ = $1;
 	} |
-	single_module_instantiation '{' module_instantiation_list '}' {
+	if_statement TOK_ELSE children_instantiation {
 		$$ = $1;
 		if ($$) {
-			$$->children = $3->children;
+			$$->else_children = $3->children;
 		} else {
 			for (int i = 0; i < $3->children.count(); i++)
 				delete $3->children[i];
 		}
 		$3->children.clear();
 		delete $3;
+	} ;
+
+module_instantiation:
+	single_module_instantiation ';' {
+		$$ = $1;
 	} |
-	single_module_instantiation module_instantiation {
+	single_module_instantiation children_instantiation {
 		$$ = $1;
 		if ($$) {
-			if ($2)
-				$$->children.append($2);
+			$$->children = $2->children;
 		} else {
-			delete $2;
+			for (int i = 0; i < $2->children.count(); i++)
+				delete $2->children[i];
 		}
+		$2->children.clear();
+		delete $2;
+	} |
+	ifelse_statement {
+		$$ = $1;
 	} ;
 
 module_instantiation_list: