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dpgeorgedpgeorge
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py/parse: Treat constants that start with underscore as private.
Assignments of the form "_id = const(value)" are treated as private (following a similar CPython convention) and code is no longer emitted for the assignment to a global variable. See issue adafruit#2111.
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‎py/parse.c‎

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@@ -461,6 +461,8 @@ STATIC const mp_rom_map_elem_t mp_constants_table[] = {
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STATIC MP_DEFINE_CONST_MAP(mp_constants_map, mp_constants_table);
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#endif
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STATIC void push_result_rule(parser_t *parser, size_t src_line, const rule_t *rule, size_t num_args);
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#if MICROPY_COMP_CONST_FOLDING
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STATIC bool fold_constants(parser_t *parser, const rule_t *rule, size_t num_args) {
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// this code does folding of arbitrary integer expressions, eg 1 + 2 * 3 + 4
@@ -587,6 +589,15 @@ STATIC bool fold_constants(parser_t *parser, const rule_t *rule, size_t num_args
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assert(elem->value == MP_OBJ_NULL);
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elem->value = MP_OBJ_NEW_SMALL_INT(value);
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// If the constant starts with an underscore then treat it as a private
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// variable and don't emit any code to store the value to the id.
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if (qstr_str(id)[0] == '_') {
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pop_result(parser); // pop const(value)
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pop_result(parser); // pop id
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push_result_rule(parser, 0, rules[RULE_pass_stmt], 0); // replace with "pass"
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return true;
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}
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// replace const(value) with value
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pop_result(parser);
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push_result_node(parser, pn_value);

‎tests/micropython/const.py‎

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@@ -9,3 +9,15 @@ def f():
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print(X, Y + 1)
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f()
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_X = const(12)
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_Y = const(_X + 34)
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print(_X, _Y)
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class A:
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Z = const(1)
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_Z = const(2)
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print(Z, _Z)
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print(hasattr(A, 'Z'), hasattr(A, '_Z'))

‎tests/micropython/const.py.exp‎

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@@ -1,2 +1,5 @@
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123 580
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123 580
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12 46
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1 2
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True False

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