Some new list functions and better error handling

New list functions include (append) (at) (rest) and (reverse). Single quotes now supported for strings.

src/env.c

@@ -28,7 +28,7 @@ Object fetchFromEnvironment(const char *name, struct Environment *env)
         debugObj(&env->objects[i]);
         if(strcmp(name, env->strings[i]) == 0) {
             printd("Returning!\n");
-            return env->objects[i];
+            return cloneObject(env->objects[i]);
         }
     }
 
@@ -191,10 +191,16 @@ struct Environment defaultEnv()
     addFunc("=", &equ, &e);
     addFunc(">", &gth, &e);
     addFunc("<", &lth, &e);
-    addFunc("len", &len, &e);
+
     addFunc("cat", &catObjects, &e);
     addFunc("fil", &filter, &e);
 
+    addFunc("len", &len, &e);
+    addFunc("ap", &append, &e);
+    addFunc("at", &at, &e);
+    addFunc("rest", &rest, &e);
+    addFunc("rev", &reverse, &e);
+
     int i = 0;
     while(codes[i]) {
         parseEval(codes[i++], &e);

src/object.c

@@ -33,7 +33,13 @@ int listLength(const Object *listObj)
 }
 
 Object len(Object obj1, Object o_ignore, struct Environment *e_ignore)
-    { return numberObject(listLength(&obj1)); }
+{
+    Object o = numberObject(listLength(&obj1));
+    if(o.number < 0) {
+        return errorObject(NOT_A_LIST);
+    }
+    return o;
+}
 
 /**
  * Returns a pointer to the Object at the given index in a given list
@@ -207,7 +213,9 @@ static const char *errorText[] = {
     "LISTS_NOT_SAME_SIZE",
     "SYMBOLS_CANT_START_WITH_DIGITS",
     "UNSUPPORTED_NUMBER_TYPE",
-    "NOT_A_SYMBOL"
+    "NOT_A_SYMBOL",
+    "ONLY_ONE_ARGUMENT",
+    "NOT_A_LIST"
 };
 
 /**
@@ -285,7 +293,11 @@ char* stringObj(char *dest, const Object *obj)
             stringList(dest, obj);
             break;
         case TYPE_ERROR:
+            #ifdef STANDALONE
+            snprintf(dest, RESULT_LENGTH, "%s", errorText[(int)(obj->err)]);
+            #else
             snprintf(dest, RESULT_LENGTH, "E%d", obj->err);
+            #endif
             break;
         case TYPE_FUNC:
         case TYPE_LAMBDA:
@@ -352,7 +364,6 @@ void _printObj(const Object *obj, int newline)
         printf("%s\n", temp);
     else
         printf("%s", temp);
-    printErr(obj);
 }
 
 /**
@@ -361,7 +372,7 @@ void _printObj(const Object *obj, int newline)
  * If the DEBUG flag is set, the Object's type will be printed first
  * @param obj The Object to print
  */
-void printObj(const Object *obj)
+inline void printObj(const Object *obj)
 {
     _printObj(obj, 1);
 }
@@ -661,6 +672,11 @@ inline Object constructLambda(const Object *params, const Object *body)
     return o;
 }
 
+inline int isError(const Object obj, const enum errorCode err)
+{
+    return obj.type == TYPE_ERROR && obj.err == err;
+}
+
 inline Object errorObject(enum errorCode err)
 {
     Object o = newObject(TYPE_ERROR);

src/object.h

@@ -17,8 +17,6 @@
 #define P1 POINTER
 #define P2 _element2
 
-#define SKIP_FIRST() if(_element == _list->list) {continue;}
-
 enum errorCode {
     MISMATCHED_PARENS,
     BAD_LIST_OF_SYMBOL_STRINGS,
@@ -36,7 +34,9 @@ enum errorCode {
     LISTS_NOT_SAME_SIZE,
     SYMBOLS_CANT_START_WITH_DIGITS,
     UNSUPPORTED_NUMBER_TYPE,
-    NOT_A_SYMBOL
+    NOT_A_SYMBOL,
+    ONLY_ONE_ARGUMENT,
+    NOT_A_LIST
 };
 
 #define MALLOC_FLAG 64
@@ -101,6 +101,7 @@ void appendList(Object *dest, const Object *src);
 
 int isStringy(const Object test);
 int isValidType(const Object test);
+int isError(const Object obj, const enum errorCode err);
 
 Object cloneList(const Object src);
 Object cloneString(Object obj);

src/pebblisp.c

@@ -40,7 +40,7 @@ Object evalMapArgs(const Object *argForms, struct Environment *env)
     if(!argForms)
         return errorObject(NULL_MAP_ARGS);
     
-    const Object lambda = eval(argForms, env);
+    Object lambda = eval(argForms, env);
     const Object *inputList = argForms->forward;
 
     if(lambda.type != TYPE_LAMBDA || inputList->type != TYPE_LIST)
@@ -61,6 +61,7 @@ Object evalMapArgs(const Object *argForms, struct Environment *env)
         deleteEnv(&newEnv);
         cleanObject(&tempList);
     }
+    cleanObject(&lambda);
 
     return list;
 }
@@ -130,6 +131,12 @@ Object eval(const Object *obj, struct Environment *env)
                 eval_forms(rest, obj, env);
 
                 Object func_eval = rest[0];
+                if(length == 1) {
+                    func_eval = first_eval.func(
+                            func_eval, errorObject(ONLY_ONE_ARGUMENT), env);
+                    if(isError(func_eval, ONLY_ONE_ARGUMENT)) // Consider it a partial function
+                        return cloneObject(*obj);
+                } else {
                     for(int i = 1; i < length; i++) {
                         Object toClean = func_eval;
                         func_eval = first_eval.func(func_eval, rest[i], env);
@@ -137,10 +144,7 @@ Object eval(const Object *obj, struct Environment *env)
                             cleanObject(&toClean);
                         cleanObject(&rest[i]);
                     }
-
+                }
-                // Consider the object a partial function
-                if(length == 1)
-                    return cloneObject(*obj);
 
                 return func_eval;
 
@@ -149,6 +153,7 @@ Object eval(const Object *obj, struct Environment *env)
                         envForLambda(&first_eval.lambda->params, first_form->forward, env);
                 Object ret = eval(&first_eval.lambda->body, &newEnv);
                 deleteEnv(&newEnv);
+                cleanObject(&first_eval);
                 return ret;
 
             } else {
@@ -233,6 +238,9 @@ Object _basicOp(const Object *obj1, const Object *obj2, const char op,
 Object basicOp(const Object *obj1, const Object *obj2, const char op,
                struct Environment *env)
 {
+    if(isError(*obj2, ONLY_ONE_ARGUMENT))
+        return *obj2;
+
     int lists = (obj1->type == TYPE_LIST) + (obj2->type == TYPE_LIST);
     if(lists == 0) {
         return _basicOp(obj1, obj2, op, env);
@@ -285,14 +293,56 @@ Object filter(Object obj1, Object obj2, struct Environment *env)
     FOR_POINTER_IN_LIST(filteringList) {
         Object conditional = cloneObject(obj1);
         nf_addToList(&conditional, *POINTER); // cloneObject()?
-        conditional = eval(&conditional, env);
+        Object result = eval(&conditional, env);
-        if(conditional.number == 1) {
+        cleanObject(&conditional);
+        if(result.number == 1) {
             nf_addToList(&filteredList, *POINTER);
         }
     }
     return filteredList;
 }
 
+Object append(Object list, Object newElement, struct Environment *env)
+{
+    Object newList = cloneObject(list);
+    nf_addToList(&newList, newElement);
+    return newList;
+}
+
+Object at(Object index, Object list, struct Environment *env)
+{
+    return cloneObject(*itemAt(&list, index.number));
+}
+
+Object rest(Object list, Object ignore, struct Environment *env)
+{
+    Object ret = listObject();
+    Object *l = &list;
+    FOR_POINTER_IN_LIST(l) {
+        if(POINTER == l->list)
+            continue;
+        nf_addToList(&ret, *POINTER);
+    }
+    return ret;
+}
+
+Object reverse(Object _list, Object ignore, struct Environment *ignore2)
+{
+    const Object *list = &_list;
+    Object rev = listObject();
+
+    Object *tail = NULL;
+    FOR_POINTER_IN_LIST(list) {
+        Object *oldTail = tail;
+        allocObject(&tail, cloneObject(*POINTER));
+        if(oldTail)
+            tail->forward = oldTail;
+    }
+
+    rev.list = tail;
+    return rev;
+}
+
 void copySlice(char * dest, struct Slice *src)
 {
     if(!dest || !src)
@@ -343,6 +393,8 @@ Result readSeq(struct Slice *tokens)
             return result(res, rest);
         }
         Result r = parse(tokens);
+        if(r.obj.type == TYPE_ERROR)
+            return r;
         nf_addToList(&res, cloneObject(r.obj));
         tokens = r.slices;
         cleanObject(&r.obj);
@@ -377,7 +429,7 @@ Object parseAtom(struct Slice *s)
     } else if (s->length == 1 && (s->text[0] == 'F' || s->text[0] == 'f')) {
         return boolObject(0);
 
-    } else if (s->text[0] == '"') {
+    } else if (s->text[0] == '"' || s->text[0] == '\'') {
         return objFromSlice(s->text, s->length);
     } else {
         return symFromSlice(s->text, s->length);
@@ -411,6 +463,8 @@ Object parseEval(const char *input, struct Environment *env)
     struct Slice *tok = tokens;
     if(tok[i].text[0] != '(') {
         Object parsed = parse(tok).obj;
+        if(parsed.type == TYPE_ERROR)
+            return parsed;
         obj = eval(&parsed, env);
         cleanObject(&parsed);
     } else {
@@ -422,6 +476,8 @@ Object parseEval(const char *input, struct Environment *env)
                 if(parens == 0) {
                     cleanObject(&obj);
                     Object parsed = parse(tok).obj;
+                    if(parsed.type == TYPE_ERROR)
+                        return parsed;
                     tok = &tok[i + 1];
                     i = -1;
                     //printObj(&parsed);

src/pebblisp.h

@@ -50,5 +50,9 @@ BASIC_OP(gth); BASIC_OP(lth);
 #undef BASIC_OP
 Object catObjects(const Object obj1, const Object obj2, struct Environment *env);
 Object filter(Object obj1, Object obj2, struct Environment *env);
+Object append(Object list, Object newElement, struct Environment *env);
+Object at(Object index, Object list, struct Environment *env);
+Object rest(Object list, Object ignore, struct Environment *env);
+Object reverse(Object _list, Object ignore, struct Environment *ignore2);
 
 #endif

src/tokens.c

@@ -79,8 +79,9 @@ struct Slice *nf_tokenize(const char *input)
         if(isSingle(input[i])) {
             i++;
 
-        } else if(input[i] == '"') {
+        } else if(input[i] == '"' || input[i] == '\'') {
-            while(input[++i] != '"' && input[i] != '\0') {
+            const char quote = input[i];
+            while(input[++i] != quote && input[i] != '\0') {
                 l++;
             }
             i++;