Merge pull request #6063 from Goober5000/sexp_boolean

allow boolean and numeric scripted SEXPs to return special values

Author: Goober5000

code/parse/sexp/LuaSEXP.cpp

@@ -10,6 +10,7 @@
 #include "parse/parselo.h"
 #include "parse/sexp.h"
 #include "parse/sexp/sexp_lookup.h"
+#include "scripting/api/objs/enums.h"
 #include "scripting/api/objs/hudgauge.h"
 #include "scripting/api/objs/message.h"
 #include "scripting/api/objs/model.h"
@@ -32,7 +33,8 @@ using namespace luacpp;
 
 namespace sexp {
 
-static SCP_unordered_map<SCP_string, int> parameter_type_mapping{{ "boolean",      OPF_BOOL },
+static SCP_unordered_map<SCP_string, int> parameter_type_mapping {
+														  { "boolean",      OPF_BOOL },
 														  { "number",       OPF_NUMBER },
 														  { "ship",         OPF_SHIP },
 														  { "shipname",     OPF_SHIP },
@@ -337,6 +339,34 @@ luacpp::LuaValue LuaSEXP::sexpToLua(int node, int argnum, int parent_node) const
 		}
 	}
 }
+bool LuaSEXP::maybeExtractSexpSpecialRetVal(const luacpp::LuaValue& value, int& sexp_retval) {
+	// see if this return value is actually a SEXP_ enum
+	if (value.getValueType() == ValueType::USERDATA) {
+		try {
+			using namespace scripting::api;
+			enum_h enumeration;
+			value.getValue(l_Enum.Get(&enumeration));	// this might throw a LuaException
+			switch (enumeration.index) {
+				case LE_SEXP_TRUE:
+				case LE_SEXP_FALSE:
+				case LE_SEXP_KNOWN_FALSE:
+				case LE_SEXP_KNOWN_TRUE:
+				case LE_SEXP_UNKNOWN:
+				case LE_SEXP_NAN:
+				case LE_SEXP_NAN_FOREVER:
+				case LE_SEXP_CANT_EVAL:
+					sexp_retval = *enumeration.value;
+					return true;
+				default:
+					break;
+			}
+		} catch (const LuaException& le) {
+			// just ignore the exception because we follow a different code path if the conversion failed
+			SCP_UNUSED(le);
+		}
+	}
+	return false;
+}
 int LuaSEXP::getSexpReturnValue(const LuaValueList& retVals) const {
 	switch (_return_type) {
 	case OPR_NUMBER:
@@ -347,6 +377,10 @@ int LuaSEXP::getSexpReturnValue(const LuaValueList& retVals) const {
 					retVals.size());
 			return 0;
 		} else if (retVals[0].getValueType() != ValueType::NUMBER) {
+			int sexp_retval;
+			if (maybeExtractSexpSpecialRetVal(retVals[0], sexp_retval)) {
+				return sexp_retval;
+			}
 			Warning(LOCATION, "Wrong return type detected for Lua SEXP '%s', expected a number.", _name.c_str());
 			return 0;
 		} else {
@@ -360,6 +394,10 @@ int LuaSEXP::getSexpReturnValue(const LuaValueList& retVals) const {
 					retVals.size());
 			return SEXP_FALSE;
 		} else if (retVals[0].getValueType() != ValueType::BOOLEAN) {
+			int sexp_retval;
+			if (maybeExtractSexpSpecialRetVal(retVals[0], sexp_retval)) {
+				return sexp_retval;
+			}
 			Warning(LOCATION, "Wrong return type detected for Lua SEXP '%s', expected a boolean.", _name.c_str());
 			return SEXP_FALSE;
 		} else {

code/parse/sexp/LuaSEXP.h

@@ -30,6 +30,9 @@ class LuaSEXP : public DynamicSEXP {
 	// just a helper for parseTable
 	static bool parseCheckEndOfDescription();
 
+	// another helper
+	static bool maybeExtractSexpSpecialRetVal(const luacpp::LuaValue& value, int& sexp_retval);
+
  public:
 	static std::pair<SCP_string, int> get_parameter_type(const SCP_string& name);
 	static int get_return_type(const SCP_string& name);

code/scripting/api/objs/enums.cpp

@@ -172,6 +172,14 @@ const lua_enum_def_list Enumerations[] = {
 	{"SCROLLBACK_SOURCE_SATISFIED", LE_SCROLLBACK_SOURCE_SATISFIED, true},
 	{"SCROLLBACK_SOURCE_COMMAND", LE_SCROLLBACK_SOURCE_COMMAND, true},
 	{"SCROLLBACK_SOURCE_NETPLAYER", LE_SCROLLBACK_SOURCE_NETPLAYER, true},
+	{"SEXP_TRUE", LE_SEXP_TRUE, SEXP_TRUE, true},
+	{"SEXP_FALSE", LE_SEXP_FALSE, SEXP_FALSE, true},
+	{"SEXP_KNOWN_FALSE", LE_SEXP_KNOWN_FALSE, SEXP_KNOWN_FALSE, true},
+	{"SEXP_KNOWN_TRUE", LE_SEXP_KNOWN_TRUE, SEXP_KNOWN_TRUE, true},
+	{"SEXP_UNKNOWN", LE_SEXP_UNKNOWN, SEXP_UNKNOWN, true},
+	{"SEXP_NAN", LE_SEXP_NAN, SEXP_NAN, true},
+	{"SEXP_NAN_FOREVER", LE_SEXP_NAN_FOREVER, SEXP_NAN_FOREVER, true},
+	{"SEXP_CANT_EVAL", LE_SEXP_CANT_EVAL, SEXP_CANT_EVAL, true},
 };
 
 const size_t Num_enumerations = sizeof(Enumerations) / sizeof(lua_enum_def_list);

code/scripting/api/objs/enums.h

@@ -171,6 +171,14 @@ enum lua_enum : int32_t {
 	LE_SCROLLBACK_SOURCE_SATISFIED,
 	LE_SCROLLBACK_SOURCE_COMMAND,
 	LE_SCROLLBACK_SOURCE_NETPLAYER,
+	LE_SEXP_TRUE,
+	LE_SEXP_FALSE,
+	LE_SEXP_KNOWN_FALSE,
+	LE_SEXP_KNOWN_TRUE,
+	LE_SEXP_UNKNOWN,
+	LE_SEXP_NAN,
+	LE_SEXP_NAN_FOREVER,
+	LE_SEXP_CANT_EVAL,
 	ENUM_NEXT_INDEX,
 	ENUM_COMBINATION,
 	ENUM_INVALID