Dedicated getPrompt() function.

Can now handle strings or lambdas.

src/pebblisp.c

@@ -1,9 +1,6 @@
 #ifdef STANDALONE
 #define _GNU_SOURCE
 
-#include <signal.h>
-#include <ucontext.h>
-
 #endif
 
 #include "pebblisp.h"
@@ -19,6 +16,9 @@
 #include <readline/readline.h>
 #include <readline/history.h>
 
+#include <signal.h>
+#include <ucontext.h>
+
 #include "web.h"
 
 #endif
@@ -596,21 +596,39 @@ int _readFile(FILE* input, struct Environment* env)
     return 0;
 }
 
+char* getPrompt(struct Environment* env)
+{
+    Object prompt = fetchFromEnvironment("prompt", env);
+    prompt = cloneObject(prompt);
+    if (prompt.type == TYPE_STRING) {
+        char* ret = readline(prompt.string);
+        cleanObject(&prompt);
+        return ret;
+    }
+    Object param = stringFromSlice("", 1);
+    Object e = listEvalLambda(&prompt, &param, 2, env);
+    cleanObject(&prompt);
+    cleanObject(&param);
+    char* ret = readline(e.string);
+    cleanObject(&e);
+    return ret;
+}
+
 void repl(struct Environment* env)
 {
     char* buf;
-    Object prompt;
     using_history();
 
-    while ((buf = readline((prompt = fetchFromEnvironment("prompt", env)).string)) != NULL) {
+    while ((buf = getPrompt(env)) != NULL) {
-        cleanObject(&prompt);
         if (strcmp("q", buf) == 0) {
             free(buf);
             break;
         }
-        if (buf[0] != '\0') {
+        if (buf[0] == '\0') {
-            add_history(buf);
+            free(buf);
+            continue;
         }
+        add_history(buf);
         if (buf[0] == '?' && (buf[1] == ' ' || buf[1] == '\0')) {
             char* oldBuf = buf;
             buf = malloc(sizeof(char) * strlen(buf + 3));
@@ -633,7 +651,6 @@ void repl(struct Environment* env)
         free(output);
         printf("\n");
     }
-    cleanObject(&prompt);
 }
 
 void loadArgsIntoEnv(int argc, const char* argv[], struct Environment* env)