MOHAWK: Implement stringLen and substring LBCode functions.

2 files changed, 29 insertions, 2 deletions

diff --git a/engines/mohawk/livingbooks_code.cpp b/engines/mohawk/livingbooks_code.cpp
index e9ef2516e2..6531f65753 100644
--- a/engines/mohawk/livingbooks_code.cpp
+++ b/engines/mohawk/livingbooks_code.cpp
@@ -686,8 +686,8 @@ struct CodeCommandInfo {
 CodeCommandInfo generalCommandInfo[NUM_GENERAL_COMMANDS] = {
 	{ "eval", &LBCode::cmdEval },
 	{ "random", &LBCode::cmdRandom },
-	{ "stringLen", 0 },
-	{ "substring", 0 },
+	{ "stringLen", &LBCode::cmdStringLen },
+	{ "substring", &LBCode::cmdSubstring },
 	{ "max", 0 },
 	{ "min", 0 },
 	{ "abs", 0 },
@@ -861,6 +861,31 @@ void LBCode::cmdRandom(const Common::Array<LBValue> &params) {
 	_stack.push(_vm->_rnd->getRandomNumberRng(min, max));
 }
 
+void LBCode::cmdStringLen(const Common::Array<LBValue> &params) {
+	if (params.size() != 1)
+		error("incorrect number of parameters (%d) to stringLen", params.size());
+
+	const Common::String &string = params[0].toString();
+	_stack.push(string.size());
+}
+
+void LBCode::cmdSubstring(const Common::Array<LBValue> &params) {
+	if (params.size() != 3)
+		error("incorrect number of parameters (%d) to substring", params.size());
+
+	const Common::String &string = params[0].toString();
+	uint begin = params[1].toInt();
+	uint end = params[2].toInt();
+	if (begin == 0)
+		error("invalid substring call (%d to %d)", begin, end);
+	if (begin > end || end > string.size()) {
+		_stack.push(Common::String());
+		return;
+	}
+	Common::String substring(string.c_str() + (begin - 1), end - begin + 1);
+	_stack.push(substring);
+}
+
 void LBCode::cmdGetRect(const Common::Array<LBValue> &params) {
 	if (params.size() < 2) {
 		_stack.push(getRectFromParams(params));
diff --git a/engines/mohawk/livingbooks_code.h b/engines/mohawk/livingbooks_code.h
index 9c58ed7a46..79c9af94f7 100644
--- a/engines/mohawk/livingbooks_code.h
+++ b/engines/mohawk/livingbooks_code.h
@@ -222,6 +222,8 @@ public:
 	void cmdUnimplemented(const Common::Array<LBValue> &params);
 	void cmdEval(const Common::Array<LBValue> &params);
 	void cmdRandom(const Common::Array<LBValue> &params);
+	void cmdStringLen(const Common::Array<LBValue> &params);
+	void cmdSubstring(const Common::Array<LBValue> &params);
 	void cmdGetRect(const Common::Array<LBValue> &params);
 	void cmdTopLeft(const Common::Array<LBValue> &params);
 	void cmdBottomRight(const Common::Array<LBValue> &params);