Allow "or else" construct to be used for error recovery

doc/function/to_int.txt

@@ -21,6 +21,10 @@ Convert any value to a [[type:int]].
 > to_int(true)  == 1
 > to_int(rgb(255,255,255)) == 255
 
+Use @or else@ to recover from errors:
+> to_number("not a number") or else 0  ==  0
+> to_number("123")          or else 0  ==  123
+
 --See also--
 | [[fun:to_real]]		Convert any value to a [[type:double]]
 | [[fun:to_number]]		Convert any value to a number

doc/function/to_number.txt

@@ -20,6 +20,10 @@ Otherwise it is converted to a [[type:double]].
 > to_number("1")   == 1
 > to_number("1.5") == 1.5
 
+Use @or else@ to recover from errors:
+> to_number("not a number") or else 0  ==  0
+> to_number("123")          or else 0  ==  123
+
 --See also--
 | [[fun:to_int]]		Convert any value to a [[type:int]]
 | [[fun:to_real]]		Convert any value to a [[type:double]]

doc/function/to_real.txt

@@ -16,6 +16,10 @@ Convert any value to a [[type:double]].
 > to_real(1)     == 1.0
 > to_real("1.5") == 1.5
 
+Use @or else@ to recover from errors:
+> to_number("not a number") or else 0.0  ==  0.0
+> to_number("123")          or else 0.0  ==  123.0
+
 --See also--
 | [[fun:to_int]]		Convert any value to a [[type:int]]
 | [[fun:to_number]]		Convert any value to a number

src/script/functions/basic.cpp

@@ -72,21 +72,29 @@ SCRIPT_FUNCTION(to_string) {
 SCRIPT_FUNCTION(to_int) {
 	ScriptValueP input = ctx.getVariable(SCRIPT_VAR_input);
 	ScriptType t = input->type();
-	int result;
-	if (t == SCRIPT_BOOL) {
-		result = (bool)*input ? 1 : 0;
-	} else if (t == SCRIPT_COLOR) {
-		AColor c = (AColor)*input;
-		result = (c.Red() + c.Blue() + c.Green()) / 3;
-	} else {
-		result = (int)*input;
+	try {
+		int result;
+		if (t == SCRIPT_BOOL) {
+			result = (bool)*input ? 1 : 0;
+		} else if (t == SCRIPT_COLOR) {
+			AColor c = (AColor)*input;
+			result = (c.Red() + c.Blue() + c.Green()) / 3;
+		} else {
+			result = (int)*input;
+		}
+		SCRIPT_RETURN(result);
+	} catch (const ScriptError& e) {
+		return new_intrusive1<ScriptDelayedError>(e);
 	}
-	SCRIPT_RETURN(result);
 }
 
 SCRIPT_FUNCTION(to_real) {
-	SCRIPT_PARAM_C(double, input);
-	SCRIPT_RETURN(input);
+	try {
+		SCRIPT_PARAM_C(double, input);
+		SCRIPT_RETURN(input);
+	} catch (const ScriptError& e) {
+		return new_intrusive1<ScriptDelayedError>(e);
+	}
 }
 
 SCRIPT_FUNCTION(to_number) {
@@ -100,25 +108,41 @@ SCRIPT_FUNCTION(to_number) {
 	} else if (t == SCRIPT_DOUBLE) {
 		SCRIPT_RETURN((double)*input);
 	} else {
-		SCRIPT_RETURN((int)*input);
+		String s = input->toString();
+		long l; double d;
+		if (s.ToLong(&l)) {
+			SCRIPT_RETURN((int)l);
+		} else if (s.ToDouble(&d)) {
+			SCRIPT_RETURN((double)d);
+		} else {
+			return delayError(_ERROR_2_("can't convert", input->typeName(), _TYPE_("double")));
+		}
 	}
 }
 
 SCRIPT_FUNCTION(to_boolean) {
 	ScriptValueP input = ctx.getVariable(SCRIPT_VAR_input);
-	ScriptType t = input->type();
-	bool result;
-	if (t == SCRIPT_INT) {
-		result = (int)*input != 0;
-	} else {
-		result = (bool)*input;
+	try {
+		ScriptType t = input->type();
+		bool result;
+		if (t == SCRIPT_INT) {
+			result = (int)*input != 0;
+		} else {
+			result = (bool)*input;
+		}
+		SCRIPT_RETURN(result);
+	} catch (const ScriptError& e) {
+		return new_intrusive1<ScriptDelayedError>(e);
 	}
-	SCRIPT_RETURN(result);
 }
 
 SCRIPT_FUNCTION(to_color) {
-	SCRIPT_PARAM_C(AColor, input);
-	SCRIPT_RETURN(input);
+	try {
+		SCRIPT_PARAM_C(AColor, input);
+		SCRIPT_RETURN(input);
+	} catch (const ScriptError& e) {
+		return new_intrusive1<ScriptDelayedError>(e);
+	}
 }
 
 // ----------------------------------------------------------------------------- : Math

tools/website/drupal/mse-drupal-modules/highlight.inc

@@ -8,8 +8,13 @@ $built_in_functions = array(
 	'to_string'		=>'',
 	'to_int'		=>'',
 	'to_real'		=>'',
+	'to_number'		=>'',
 	'to_boolean'		=>'',
 	'to_color'		=>'',
+	// numbers
+	'abs'			=>'',
+	'random_int'		=>'',
+	'random_real'		=>'',
 	// text
 	'to_upper'		=>'',
 	'to_lower'		=>'',
@@ -36,6 +41,8 @@ $built_in_functions = array(
 	'number_of_items'	=>'',
 	'sort_list'		=>'',
 	'filter_list'		=>'',
+	'random_shuffle'	=>'',
+	'random_select'		=>'',
 	// keywords
 	'expand_keywords'	=>'',	'expand_keywords_rule'=>'expand_keywords',
 	'keyword_usage'		=>'',
@@ -159,7 +166,7 @@ function highlight_script($code) {
 			if ($matches[2] == '{') $string .= 's';
 		} else if (preg_match("@^\\#.*@",$code, $matches)) {
 			$ret .= "<span class='hl-comment'>" . $matches[0] . "</span>";
-		} else if (preg_match("@^([-+*/=!.\@]|&lt;|&gt;)+|^:=@",$code, $matches)) {
+		} else if (preg_match("@^([-+*/=!.\@^]|&lt;|&gt;)+|^:=@",$code, $matches)) {
 			$ret .= "<span class='hl-op'>" . $matches[0] . "</span>";
 		} else if (preg_match("@^([}]|[\\(\\)\\[\\]{,]+)@",$code, $matches)) {
 			$ret .= "<span class='hl-paren'>" . $matches[0] . "</span>";