Fix String factory

object.c

@@ -249,13 +249,23 @@ oop makeString(char *value)
 // value will be used directly
 oop makeStringFrom(char *value, size_t l)
 {
-    oop newString = memcheck(malloc(sizeof(union object)));
+    oop newString = malloc(sizeof(union object));
     newString->type = String;
     newString->String.value = value;
     newString->String.size = l;
     return newString;
 }
 
+oop makeStringFromChar(char c, int repeat)
+{
+    char *str= malloc(sizeof(char) * (repeat + 1));
+    for (int i=0; i<repeat; ++i) {
+        str[i]= c;
+    }
+    str[repeat]= '\0';
+    return makeStringFrom(str, repeat);
+}
+
 size_t string_size(oop s)
 {
     return get(s, String, size);

parse.leg

@@ -1948,8 +1948,39 @@ oop prim_import(oop scope, oop params)
 
 oop prim_String(oop scope, oop params)
 {
-    if (!map_hasIntegerKey(params, 0)) return null;
-    return makeString(printString(get(params, Map, elements)[0].value));
+    if (!map_hasIntegerKey(params, 0)) return makeString("");
+    oop arg= get(params, Map, elements)[0].value;
+    switch (getType(arg)) {
+        case Undefined: {
+            return makeString("");
+        }
+        case Integer: {
+            int repeat= getInteger(arg);
+            if (!map_hasIntegerKey(params, 1)) {
+                // I put 0 otherwise '\0' won't be printed and can't be seen
+                return makeStringFromChar('0', repeat);
+            }
+            char c= getInteger(get(params, Map, elements)[1].value);
+            return makeStringFromChar(c, repeat);
+        }
+        case String: {
+            return clone(arg);
+        }
+        case Map: {
+            if (map_isArray(arg)) {
+                size_t len= map_size(arg);
+                char *str= malloc(sizeof(char) * len + 1);
+                for (size_t i=0; i < len; ++i) {
+                    str[i]= getInteger(get(arg, Map, elements)[i].value);
+                }
+                return makeStringFrom(str, len);
+            }
+        }
+        case Symbol: {
+            return makeString(get(arg, Symbol, name));
+        }
+    }
+    return null;
 }
 
 oop prim_Integer(oop scope, oop params)