Mercurial > cpython-lru_cache-weakref
diff Python/symtable.c @ 58250:edfed0e32ced legacy-trunk
Issue #2333: Backport set and dict comprehensions syntax.
| author | Alexandre Vassalotti <alexandre@peadrop.com> |
|---|---|
| date | Mon, 11 Jan 2010 22:36:12 +0000 |
| parents | c2fdf25329ff |
| children | fd25030223b0 |
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--- a/Python/symtable.c Mon Jan 11 17:15:13 2010 +0000 +++ b/Python/symtable.c Mon Jan 11 22:36:12 2010 +0000 @@ -166,6 +166,8 @@ static int symtable_visit_stmt(struct symtable *st, stmt_ty s); static int symtable_visit_expr(struct symtable *st, expr_ty s); static int symtable_visit_genexp(struct symtable *st, expr_ty s); +static int symtable_visit_setcomp(struct symtable *st, expr_ty e); +static int symtable_visit_dictcomp(struct symtable *st, expr_ty e); static int symtable_visit_arguments(struct symtable *st, arguments_ty); static int symtable_visit_excepthandler(struct symtable *st, excepthandler_ty); static int symtable_visit_alias(struct symtable *st, alias_ty); @@ -177,7 +179,8 @@ static int symtable_implicit_arg(struct symtable *st, int pos); -static identifier top = NULL, lambda = NULL, genexpr = NULL; +static identifier top = NULL, lambda = NULL, genexpr = NULL, setcomp = NULL, + dictcomp = NULL; #define GET_IDENTIFIER(VAR) \ ((VAR) ? (VAR) : ((VAR) = PyString_InternFromString(# VAR))) @@ -1222,6 +1225,14 @@ if (!symtable_visit_genexp(st, e)) return 0; break; + case SetComp_kind: + if (!symtable_visit_setcomp(st, e)) + return 0; + break; + case DictComp_kind: + if (!symtable_visit_dictcomp(st, e)) + return 0; + break; case Yield_kind: if (e->v.Yield.value) VISIT(st, expr, e->v.Yield.value); @@ -1462,28 +1473,81 @@ return 1; } -static int -symtable_visit_genexp(struct symtable *st, expr_ty e) +static int +symtable_new_tmpname(struct symtable *st) { + char tmpname[256]; + identifier tmp; + + PyOS_snprintf(tmpname, sizeof(tmpname), "_[%d]", + ++st->st_cur->ste_tmpname); + tmp = PyString_InternFromString(tmpname); + if (!tmp) + return 0; + if (!symtable_add_def(st, tmp, DEF_LOCAL)) + return 0; + Py_DECREF(tmp); + return 1; +} + +static int +symtable_handle_comprehension(struct symtable *st, expr_ty e, + identifier scope_name, asdl_seq *generators, + expr_ty elt, expr_ty value) +{ + int is_generator = (e->kind == GeneratorExp_kind); + int needs_tmp = !is_generator; comprehension_ty outermost = ((comprehension_ty) - (asdl_seq_GET(e->v.GeneratorExp.generators, 0))); + asdl_seq_GET(generators, 0)); /* Outermost iterator is evaluated in current scope */ VISIT(st, expr, outermost->iter); - /* Create generator scope for the rest */ - if (!GET_IDENTIFIER(genexpr) || - !symtable_enter_block(st, genexpr, FunctionBlock, (void *)e, e->lineno)) { + /* Create comprehension scope for the rest */ + if (!scope_name || + !symtable_enter_block(st, scope_name, FunctionBlock, (void *)e, 0)) { return 0; } - st->st_cur->ste_generator = 1; + st->st_cur->ste_generator = is_generator; /* Outermost iter is received as an argument */ if (!symtable_implicit_arg(st, 0)) { symtable_exit_block(st, (void *)e); return 0; } + /* Allocate temporary name if needed */ + if (needs_tmp && !symtable_new_tmpname(st)) { + symtable_exit_block(st, (void *)e); + return 0; + } VISIT_IN_BLOCK(st, expr, outermost->target, (void*)e); VISIT_SEQ_IN_BLOCK(st, expr, outermost->ifs, (void*)e); VISIT_SEQ_TAIL_IN_BLOCK(st, comprehension, - e->v.GeneratorExp.generators, 1, (void*)e); - VISIT_IN_BLOCK(st, expr, e->v.GeneratorExp.elt, (void*)e); + generators, 1, (void*)e); + if (value) + VISIT_IN_BLOCK(st, expr, value, (void*)e); + VISIT_IN_BLOCK(st, expr, elt, (void*)e); return symtable_exit_block(st, (void *)e); } + +static int +symtable_visit_genexp(struct symtable *st, expr_ty e) +{ + return symtable_handle_comprehension(st, e, GET_IDENTIFIER(genexpr), + e->v.GeneratorExp.generators, + e->v.GeneratorExp.elt, NULL); +} + +static int +symtable_visit_setcomp(struct symtable *st, expr_ty e) +{ + return symtable_handle_comprehension(st, e, GET_IDENTIFIER(setcomp), + e->v.SetComp.generators, + e->v.SetComp.elt, NULL); +} + +static int +symtable_visit_dictcomp(struct symtable *st, expr_ty e) +{ + return symtable_handle_comprehension(st, e, GET_IDENTIFIER(dictcomp), + e->v.DictComp.generators, + e->v.DictComp.key, + e->v.DictComp.value); +}
