mruby-bin-mirb: add colored output for results and errors

Result values are shown in cyan, errors in bold red.
The arrow " => " uses gray for subtle appearance.

Co-authored-by: Claude <noreply@anthropic.com>

mrbgems/mruby-bin-mirb/tools/mirb/mirb.c

@@ -45,26 +45,22 @@
 #endif
 
 static void
-p(mrb_state *mrb, mrb_value obj)
+p(mrb_state *mrb, mrb_value obj, mirb_highlighter *hl)
 {
   mrb_value val = mrb_funcall_argv(mrb, obj, MRB_SYM(inspect), 0, NULL);
-  if (!mrb->exc) {
-    fputs(" => ", stdout);
-  }
-  else {
+  if (mrb->exc) {
     val = mrb_exc_get_output(mrb, mrb->exc);
   }
   if (!mrb_string_p(val)) {
     val = mrb_obj_as_string(mrb, obj);
   }
   char* msg = mrb_locale_from_utf8(RSTRING_PTR(val), (int)RSTRING_LEN(val));
-  fwrite(msg, strlen(msg), 1, stdout);
+  mirb_highlight_print_result(hl, msg);
   mrb_locale_free(msg);
-  putc('\n', stdout);
 }
 
 static void
-p_error(mrb_state *mrb, struct RObject* exc, mrb_ccontext *cxt)
+p_error(mrb_state *mrb, struct RObject* exc, mrb_ccontext *cxt, mirb_highlighter *hl)
 {
   mrb_value val = mrb_exc_get_output(mrb, exc);
   if (!mrb_string_p(val)) {
@@ -104,9 +100,8 @@ p_error(mrb_state *mrb, struct RObject* exc, mrb_ccontext *cxt)
   }
 
   char* msg = mrb_locale_from_utf8(RSTRING_PTR(val), (int)RSTRING_LEN(val));
-  fwrite(msg, strlen(msg), 1, stdout);
+  mirb_highlight_print_error(hl, msg);
   mrb_locale_free(msg);
-  putc('\n', stdout);
 }
 
 /* Guess if the user might want to enter more
@@ -762,7 +757,7 @@ main(int argc, char **argv)
         /* did an exception occur? */
         if (mrb->exc) {
           MRB_EXC_CHECK_EXIT(mrb, mrb->exc);
-          p_error(mrb, mrb->exc, cxt);
+          p_error(mrb, mrb->exc, cxt, &editor.highlight);
           mrb->exc = 0;
         }
         else {
@@ -770,7 +765,7 @@ main(int argc, char **argv)
           if (!mrb_respond_to(mrb, result, MRB_SYM(inspect))){
             result = mrb_any_to_s(mrb, result);
           }
-          p(mrb, result);
+          p(mrb, result, &editor.highlight);
 #ifndef MRB_NO_MIRB_UNDERSCORE
           *(mrb->c->ci->stack + 1) = result;
 #endif

mrbgems/mruby-bin-mirb/tools/mirb/mirb_highlight.c

@@ -23,6 +23,9 @@
 #define DARK_IVAR      "\033[34m"    /* blue */
 #define DARK_GVAR      "\033[1;34m"  /* bold blue */
 #define DARK_REGEXP    "\033[31m"    /* red */
+#define DARK_RESULT    "\033[36m"    /* cyan (same as number) */
+#define DARK_ERROR     "\033[1;31m"  /* bold red */
+#define DARK_ARROW     "\033[90m"    /* gray */
 
 /* Light theme colors (dark colors on light background) */
 #define LIGHT_KEYWORD  "\033[35m"    /* magenta */
@@ -34,6 +37,9 @@
 #define LIGHT_IVAR     "\033[34m"    /* blue */
 #define LIGHT_GVAR     "\033[34m"    /* blue */
 #define LIGHT_REGEXP   "\033[31m"    /* red */
+#define LIGHT_RESULT   "\033[36m"    /* cyan */
+#define LIGHT_ERROR    "\033[31m"    /* red */
+#define LIGHT_ARROW    "\033[90m"    /* gray */
 
 #define COLOR_RESET    "\033[0m"
 
@@ -456,3 +462,50 @@ mirb_highlight_print_line(mirb_highlighter *hl, const char *line)
     putchar(*p++);
   }
 }
+
+/*
+ * Print result value with highlighting
+ */
+void
+mirb_highlight_print_result(mirb_highlighter *hl, const char *result)
+{
+  if (!hl->enabled) {
+    fputs(" => ", stdout);
+    fputs(result, stdout);
+    putchar('\n');
+    return;
+  }
+
+  if (hl->theme == MIRB_THEME_DARK) {
+    fputs(DARK_ARROW " => " COLOR_RESET, stdout);
+    fputs(DARK_RESULT, stdout);
+  }
+  else {
+    fputs(LIGHT_ARROW " => " COLOR_RESET, stdout);
+    fputs(LIGHT_RESULT, stdout);
+  }
+  fputs(result, stdout);
+  fputs(COLOR_RESET "\n", stdout);
+}
+
+/*
+ * Print error message with highlighting
+ */
+void
+mirb_highlight_print_error(mirb_highlighter *hl, const char *error)
+{
+  if (!hl->enabled) {
+    fputs(error, stdout);
+    putchar('\n');
+    return;
+  }
+
+  if (hl->theme == MIRB_THEME_DARK) {
+    fputs(DARK_ERROR, stdout);
+  }
+  else {
+    fputs(LIGHT_ERROR, stdout);
+  }
+  fputs(error, stdout);
+  fputs(COLOR_RESET "\n", stdout);
+}

mrbgems/mruby-bin-mirb/tools/mirb/mirb_highlight.h

@@ -81,4 +81,15 @@ void mirb_highlight_print_line(mirb_highlighter *hl, const char *line);
  */
 void mirb_highlight_reset(mirb_highlighter *hl);
 
+/*
+ * Print result value with highlighting
+ * Prints " => " prefix and the result string with appropriate colors
+ */
+void mirb_highlight_print_result(mirb_highlighter *hl, const char *result);
+
+/*
+ * Print error message with highlighting
+ */
+void mirb_highlight_print_error(mirb_highlighter *hl, const char *error);
+
 #endif /* MIRB_HIGHLIGHT_H */