Add chr() function to convert numbers to unicode characters.

src/func.cc

@@ -527,6 +527,17 @@ Value builtin_str(const Context *, const EvalContext *evalctx)
 	return Value(stream.str());
 }
 
+Value builtin_chr(const Context *, const EvalContext *evalctx)
+{
+	std::stringstream stream;
+	
+	for (size_t i = 0; i < evalctx->numArgs(); i++) {
+		const Value v = evalctx->getArgValue(i);
+		stream << v.chrString();
+	}
+	return Value(stream.str());
+}
+
 Value builtin_concat(const Context *, const EvalContext *evalctx)
 {
 	Value::VectorType result;
@@ -928,6 +939,7 @@ void register_builtin_functions()
 	Builtins::init("log", new BuiltinFunction(&builtin_log));
 	Builtins::init("ln", new BuiltinFunction(&builtin_ln));
 	Builtins::init("str", new BuiltinFunction(&builtin_str));
+	Builtins::init("chr", new BuiltinFunction(&builtin_chr));
 	Builtins::init("concat", new BuiltinFunction(&builtin_concat));
 	Builtins::init("lookup", new BuiltinFunction(&builtin_lookup));
 	Builtins::init("search", new BuiltinFunction(&builtin_search));

src/value.cc

@@ -248,6 +248,58 @@ std::string Value::toString() const
   return boost::apply_visitor(tostring_visitor(), this->value);
 }
 
+class chr_visitor : public boost::static_visitor<std::string> {
+public:
+	template <typename S> std::string operator()(const S &) const
+	{
+		return "";
+	}
+
+	std::string operator()(const double &v) const
+	{
+		char buf[8];
+		memset(buf, 0, 8);
+		if (v > 0) {
+			const gunichar c = v;
+			if (g_unichar_validate(c) && (c != 0)) {
+			    g_unichar_to_utf8(c, buf);
+			}
+		}
+		return std::string(buf);
+	}
+
+	std::string operator()(const Value::VectorType &v) const
+	{
+		std::stringstream stream;
+		for (size_t i = 0; i < v.size(); i++) {
+			stream << v[i].chrString();
+		}
+		return stream.str();
+	}
+
+	std::string operator()(const Value::RangeType &v) const
+	{
+		const boost::uint32_t steps = v.nbsteps();
+		if (steps >= 10000) {
+			PRINTB("WARNING: Bad range parameter in for statement: too many elements (%lu).", steps);
+			return "";
+		}
+
+		std::stringstream stream;
+		Value::RangeType range = v;
+		for (Value::RangeType::iterator it = range.begin();it != range.end();it++) {
+			const Value value(*it);
+			stream << value.chrString();
+		}
+		return stream.str();
+	}
+};
+
+std::string Value::chrString() const
+{
+  return boost::apply_visitor(chr_visitor(), this->value);
+}
+
 const Value::VectorType &Value::toVector() const
 {
   static VectorType empty;

src/value.h

@@ -87,6 +87,7 @@ public:
     /// return number of steps, max uint32_t value if step is 0
     boost::uint32_t nbsteps() const;
     
+    friend class chr_visitor;
     friend class tostring_visitor;
     friend class bracket_visitor;
   };
@@ -121,6 +122,7 @@ public:
   bool getDouble(double &v) const;
   bool toBool() const;
   std::string toString() const;
+  std::string chrString() const;
   const VectorType &toVector() const;
   bool getVec2(double &x, double &y) const;
   bool getVec3(double &x, double &y, double &z, double defaultval = 0.0) const;