...

c_bindings/test.c

@@ -413,11 +413,11 @@ int main(int argc, char** argv) {
 
     PRINT_TITLE("test py_repr");
     check(pkpy_eval(vm, "['1', 2, (3, '4')]"));
-    check(pkpy_py_repr(vm, -1));
+    check(pkpy_py_repr(vm));
     check(pkpy_to_string(vm, -1, &r_string));
     for(int i = 0; i < r_string.size; i++) putchar(r_string.data[i]);
     putchar('\n');
-    check(pkpy_pop(vm, 2));
+    check(pkpy_pop_top(vm));
     check(pkpy_stack_size(vm) == 0);
     return 0;
 }

docs/C-API/stack.md

@@ -6,6 +6,10 @@ order: 8
 
 ### Basic manipulation
 
++ `bool pkpy_dup(pkpy_vm*, int)`
+
+    Duplicate the value at the given index.
+
 + `bool pkpy_pop(pkpy_vm*, int)`
 
     Pop `n` values from the stack.
@@ -70,7 +74,7 @@ PK_EXPORT bool pkpy_is_none(pkpy_vm*, int i);
 
 + `pkpy_push_null(pkpy_vm*)`
 
-    Push a `PY_NULL` onto the stack.
+    Push a `PY_NULL` onto the stack. It is used for `pkpy_vectorcall`.
 
 + `pkpy_push_function(pkpy_vm*, const char* sig, pkpy_CFunction f)`
 
@@ -140,10 +144,10 @@ PK_EXPORT bool pkpy_is_none(pkpy_vm*, int i);
     ```
     [obj] -> [obj.<name> self]
     ```
-+ `bool pkpy_py_repr(pkpy_vm*, int i)`
++ `bool pkpy_py_repr(pkpy_vm*)`
 
-    Get the repr of the value at the given index and push it onto the stack.
+    Get the repr of the value at the top of the stack.
 
     ```
-    [..., value, ...] -> [..., value, ..., repr(value)]
+    [value] -> [repr(value)]
     ```

include/pocketpy/pocketpy_c.h

@@ -27,6 +27,7 @@ PK_EXPORT bool pkpy_exec(pkpy_vm*, const char* source);
 PK_EXPORT bool pkpy_exec_2(pkpy_vm*, const char* source, const char* filename, int mode, const char* module);
 
 /* Stack Manipulation */
+PK_EXPORT bool pkpy_dup(pkpy_vm*, int);
 PK_EXPORT bool pkpy_pop(pkpy_vm*, int);
 PK_EXPORT bool pkpy_pop_top(pkpy_vm*);
 PK_EXPORT bool pkpy_dup_top(pkpy_vm*);
@@ -75,7 +76,7 @@ PK_EXPORT bool pkpy_setglobal(pkpy_vm*, pkpy_CName);
 PK_EXPORT bool pkpy_eval(pkpy_vm*, const char* source);
 PK_EXPORT bool pkpy_unpack_sequence(pkpy_vm*, int size);
 PK_EXPORT bool pkpy_get_unbound_method(pkpy_vm*, pkpy_CName);
-PK_EXPORT bool pkpy_py_repr(pkpy_vm*, int i);
+PK_EXPORT bool pkpy_py_repr(pkpy_vm*);
 
 /* Error Handling */
 PK_EXPORT bool pkpy_error(pkpy_vm*, const char* name, pkpy_CString);

src/pocketpy_c.cpp

@@ -89,6 +89,16 @@ bool pkpy_exec_2(pkpy_vm* vm_handle, const char* source, const char* filename, i
     return res != nullptr;
 }
 
+bool pkpy_dup(pkpy_vm* vm_handle, int n){
+    VM* vm = (VM*) vm_handle;
+    PK_ASSERT_NO_ERROR()
+    PK_PROTECTED(
+        PyObject* item = stack_item(vm, n);
+        vm->s_data.push(item);
+    )
+    return true;
+}
+
 bool pkpy_pop(pkpy_vm* vm_handle, int n){
     VM* vm = (VM*) vm_handle;
     PK_ASSERT_NO_ERROR()
@@ -461,15 +471,15 @@ bool pkpy_get_unbound_method(pkpy_vm* vm_handle, pkpy_CName name){
     return true;
 }
 
-bool pkpy_py_repr(pkpy_vm* vm_handle, int i) {
+bool pkpy_py_repr(pkpy_vm* vm_handle) {
     VM* vm = (VM*) vm_handle;
     PK_ASSERT_NO_ERROR()
     PK_ASSERT_N_EXTRA_ELEMENTS(1)
+    PyObject* item = vm->s_data.top();
     PK_PROTECTED(
-        PyObject* item = stack_item(vm, i);
+        item = vm->py_repr(item);
-        PyObject* repr = vm->py_repr(item);
-        vm->s_data.push(repr);
     )
+    vm->s_data.top() = item;
     return true;
 }