Some echo()/print() fixes. (0.37.12)

src/vm.c

@@ -269,6 +269,8 @@ void vm_clear_output(VM *vm) {
         free_value(vm->output[i]);
     }
     vm->output_count = 0;
+    // reset partial flags
+    for (int i = 0; i < OUTPUT_SIZE; ++i) vm->output_is_partial[i] = 0;
 }
 
 void vm_free(VM *vm) {
@@ -420,6 +422,7 @@ void vm_init(VM *vm) {
     vm->sp = -1;
     vm->fp = -1;
     vm->output_count = 0;
+    for (int i = 0; i < OUTPUT_SIZE; ++i) vm->output_is_partial[i] = 0;
     vm->instr_count = 0;
     vm->exit_code = 0;
     vm->trace_enabled = 0;
@@ -475,6 +478,12 @@ static void vm_pop_frame(VM *vm) {
 void vm_print_output(VM *vm) {
     for (int i = 0; i < vm->output_count; ++i) {
         print_value(&vm->output[i]);
+        if (!vm->output_is_partial[i]) {
+            printf("\n");
+        }
+    }
+    /* If the last item was partial (from echo), terminate the line for cleanliness */
+    if (vm->output_count > 0 && vm->output_is_partial[vm->output_count - 1]) {
         printf("\n");
     }
 }

src/vm.h

@@ -72,6 +72,7 @@ struct VM {
 
     Value output[OUTPUT_SIZE]; // store printed values
     int output_count;
+    int output_is_partial[OUTPUT_SIZE]; // 1 when the corresponding output entry should not end with newline (echo)
 
     long long instr_count; // executed instructions in the last vm_run
 

src/vm/echo.c

@@ -1,12 +1,22 @@
 /**
  * Implements OP_ECHO: print top-of-stack value without trailing newline.
- * Does not store into VM output buffer; writes directly to stdout and flushes.
+ * Now stores the value into the VM's output buffer and marks it as partial,
+ * so the CLI can render echo output together with following print output.
  */
 
 case OP_ECHO: {
     Value v = pop_value(vm);
-    print_value(&v);
-    fflush(stdout);
+    Value snap = deep_copy_value(&v);
     free_value(v);
+    if (vm->output_count < OUTPUT_SIZE) {
+        int idx = vm->output_count;
+        vm->output[idx] = snap;
+        vm->output_is_partial[idx] = 1; // ECHO does not end the line
+        vm->output_count++;
+    } else {
+        free_value(snap);
+        fprintf(stderr, "Runtime error: output buffer overflow\n");
+        exit(1);
+    }
     break;
 }

src/vm/print.c

@@ -32,7 +32,10 @@ case OP_PRINT: {
     Value snap = deep_copy_value(&v);
     free_value(v);
     if (vm->output_count < OUTPUT_SIZE) {
-        vm->output[vm->output_count++] = snap;
+        int idx = vm->output_count;
+        vm->output[idx] = snap;
+        vm->output_is_partial[idx] = 0; // PRINT terminates the line
+        vm->output_count++;
     } else {
         free_value(snap);
         fprintf(stderr, "Runtime error: output buffer overflow\n");