Add system calls and some char processing.

Color REPL error output.
Add 'clear' shorthand to REPL.
Add basic switch to lib.

src/env.c

@@ -217,13 +217,16 @@ struct Environment defaultEnv()
         {"cat", &catObjects}, {"fil", &filter}, {"len", &len},
         {"ap", &append}, {"pre", &prepend},
         {"at", &at}, {"rest", &rest},
+        {"chat", &charAt},
 #ifndef LOW_MEM
         {"rev", &reverse},
 #endif
         {"isnum", &isNum}, {"isstr", &isString}, {"iserr", &isErr},
+        {"char", &charVal},
         {"eval", &parseEvalO},
         #ifdef STANDALONE
         {"prn", &print}, {"pch", &pChar}, {"penv", &printEnvO},
+        {"sys", &systemCall},
         {"loadfile", &loadFile},
         {"inp", &takeInput},
         #endif

src/examples/lib.pbl

@@ -25,14 +25,13 @@
 ; Return the smaller of the two
 (def min (fn (a b) (if (< a b) a b)))
 
-;(def switch (fn (pair_list)
-;  (if (= 0 (len pair_list))
-;  "no match"
-;  (
-;    (def _pair (at 0 pair_list))
-;    (if (at 0 _pair)
-;      (at 1 _pair)
-;      (switch (rest pair_list))
-;    )
-;  ))
-;))
+; Switch expression
+; Doesn't yet work with lambdas
+(def switch (fn (val pair_list)
+  (if (= 0 (len pair_list)) "no match" (
+    (def current (at 0 pair_list))
+    (if (= val (at 0 current)) (at 1 current) (
+      (switch val (rest pair_list))
+    ))
+  ))
+))

src/examples/repl.pbl

@@ -3,8 +3,18 @@
   (prn "pebblisp::> ")
   (def input (inp))
   (if (= input "q") () (
-      (prnl (eval input))
-      (repl)))
+      ;(switch input (
+      ;  ("clear" (fn () (sys "clear")))
+      ;))
+
+      (if (= input "") () (
+        (if (= input "clear") (sys "clear") (
+        (def ret (eval input))
+        (if (iserr ret) (prn "X  =>  ") (prn "Ok =>  "))
+        (prnl ret)
+        (prn "")))))
+      (repl)
+  ))
 )))
 
 (repl)

src/object.c

@@ -771,14 +771,20 @@ inline enum errorCode getErrorCode(const Object obj)
 #ifndef SIMPLE_ERRORS
 inline void errorAddContext(Object *o, const char* context)
 {
+    printf("o: %p\n", o);
+    printf("o->error: %s\n", o->error);
+    printf("o->error->context: %s\n", o->error->context);
     o->error->context = calloc(sizeof(char), RESULT_LENGTH);
+    printf("context: %p\n", context);
     strncpy(o->error->context, context, RESULT_LENGTH);
 }
 
 inline Object errorWithContext(enum errorCode err, const char* context)
 {
     Object o = errorObject(err);
-    errorAddContext(&o, context);
+    if (context) {
+        errorAddContext(&o, context);
+    }
     return o;
 }
 #endif

src/pebblisp.c

@@ -215,8 +215,8 @@ Object listEvalFunc(
 Object listEvalLambda(
     Object *lambda,
     const Object *remaining,
-    struct Environment *env)
-{
+    struct Environment *env
+) {
     struct Environment newEnv = envForLambda(
             &lambda->lambda->params,
             remaining,
@@ -524,12 +524,29 @@ Object isString(Object test, Object ignore, struct Environment *ignore2)
         boolObject(1) : boolObject(0);
 }
 
+// Get the int value of a string's first character
+Object charVal(Object test, Object ignore, struct Environment *ignore2)
+{
+    return numberObject(test.string[0]);
+//    return test.type == TYPE_STRING && test.string[0] == '\0' ?
+//        boolObject(1) : boolObject(0);
+}
+
 Object isErr(Object test, Object ignore, struct Environment *ignore2)
 {
     return test.type == TYPE_ERROR ?
         boolObject(1) : boolObject(0);
 }
 
+Object charAt(Object string, Object at, struct Environment *ignore)
+{
+    char* c = malloc(sizeof(char) * 2);
+    c[0] = string.string[at.number];
+    c[1] = '\0';
+    string.string = c;
+    return string;
+}
+
 #ifdef STANDALONE
 Object print(Object p, Object ignore, struct Environment *env)
 {
@@ -828,6 +845,13 @@ Object loadFile(Object filename, Object _, struct Environment *env) {
     return numberObject(1);
 }
 
+Object systemCall(Object process, Object _, struct Environment *env) {
+    if (isStringy(process)) {
+        return numberObject(system(process.string));
+    }
+    return numberObject(255);
+}
+
 void repl(struct Environment *env) {
     if (readFile(SCRIPTDIR "/repl.pbl", env) == 1) {
         fprintf(stderr, "Could not read '%s'\n", SCRIPTDIR "/repl.pbl");

src/pebblisp.h

@@ -59,6 +59,9 @@ Object isNum(Object test, Object ignore, struct Environment *ignore2);
 Object isString(Object test, Object ignore, struct Environment *ignore2);
 Object isErr(Object test, Object ignore, struct Environment *ignore2);
 
+Object charAt(Object string, Object at, struct Environment *ignore);
+Object charVal(Object test, Object ignore, struct Environment *ignore2);
+
 Object print(Object p, Object ignore, struct Environment *ignore2);
 Object pChar(Object c, Object i1, struct Environment *i2);
 Object printEnvO(Object i1, Object i2, struct Environment *env);
@@ -66,6 +69,7 @@ Object parseEvalO(Object text, Object ignore, struct Environment *env);
 
 #ifdef STANDALONE
 Object takeInput(Object i1, Object i2, struct Environment *i3);
+Object systemCall(Object call, Object _, struct Environment *i3);
 Object loadFile(Object filename, Object _, struct Environment *env);
 #endif