Ternary operator in GDScript (a if x else b)

Fixes #1961

1 files changed, 40 insertions, 0 deletions

diff --git a/modules/gdscript/gd_compiler.cpp b/modules/gdscript/gd_compiler.cpp
index 3bbd8e8f0..40bcce91c 100644
--- a/modules/gdscript/gd_compiler.cpp
+++ b/modules/gdscript/gd_compiler.cpp
@@ -662,6 +662,46 @@ int GDCompiler::_parse_expression(CodeGen& codegen,const GDParser::Node *p_expre
 					return p_stack_level|GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS;
 
 				} break;
+				// ternary operators
+				case GDParser::OperatorNode::OP_TERNARY_IF: {
+
+					// x IF a ELSE y operator with early out on failure
+
+					int res = _parse_expression(codegen,on->arguments[0],p_stack_level);
+					if (res<0)
+						return res;
+					codegen.opcodes.push_back(GDFunction::OPCODE_JUMP_IF_NOT);
+					codegen.opcodes.push_back(res);
+					int jump_fail_pos=codegen.opcodes.size();
+					codegen.opcodes.push_back(0);
+
+
+					res = _parse_expression(codegen,on->arguments[1],p_stack_level);
+					if (res<0)
+						return res;
+					
+					codegen.alloc_stack(p_stack_level); //it will be used..
+					codegen.opcodes.push_back(GDFunction::OPCODE_ASSIGN);
+					codegen.opcodes.push_back(p_stack_level|GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS);
+					codegen.opcodes.push_back(res);
+					codegen.opcodes.push_back(GDFunction::OPCODE_JUMP);
+					int jump_past_pos=codegen.opcodes.size();
+					codegen.opcodes.push_back(0);
+					
+					codegen.opcodes[jump_fail_pos]=codegen.opcodes.size();
+					res = _parse_expression(codegen,on->arguments[2],p_stack_level);
+					if (res<0)
+						return res;
+					
+					codegen.opcodes.push_back(GDFunction::OPCODE_ASSIGN);
+					codegen.opcodes.push_back(p_stack_level|GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS);
+					codegen.opcodes.push_back(res);
+					
+					codegen.opcodes[jump_past_pos]=codegen.opcodes.size();
+					
+					return p_stack_level|GDFunction::ADDR_TYPE_STACK<<GDFunction::ADDR_BITS;
+
+				} break;
 				//unary operators
 				case GDParser::OperatorNode::OP_NEG: { if (!_create_unary_operator(codegen,on,Variant::OP_NEGATE,p_stack_level)) return -1;} break;
 				case GDParser::OperatorNode::OP_NOT: { if (!_create_unary_operator(codegen,on,Variant::OP_NOT,p_stack_level)) return -1;} break;