diff options
| -rw-r--r-- | Python/ast.c | 34 |
1 files changed, 30 insertions, 4 deletions
diff --git a/Python/ast.c b/Python/ast.c index 5594ef3..94998d3 100644 --- a/Python/ast.c +++ b/Python/ast.c @@ -1388,7 +1388,10 @@ ast_for_binop(struct compiling *c, const node *n) static expr_ty ast_for_trailer(struct compiling *c, const node *n, expr_ty left_expr) { - /* trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME */ + /* trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME + subscriptlist: subscript (',' subscript)* [','] + subscript: '.' '.' '.' | test | [test] ':' [test] [sliceop] + */ REQ(n, trailer); if (TYPE(CHILD(n, 0)) == LPAR) { if (NCH(n) == 2) @@ -1404,25 +1407,48 @@ ast_for_trailer(struct compiling *c, const node *n, expr_ty left_expr) REQ(CHILD(n, 0), LSQB); REQ(CHILD(n, 2), RSQB); n = CHILD(n, 1); - if (NCH(n) <= 2) { + if (NCH(n) == 1) { slice_ty slc = ast_for_slice(c, CHILD(n, 0)); if (!slc) return NULL; return Subscript(left_expr, slc, Load, LINENO(n), c->c_arena); } else { + /* The grammar is ambiguous here. The ambiguity is resolved + by treating the sequence as a tuple literal if there are + no slice features. + */ int j; slice_ty slc; - asdl_seq *slices = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena); + expr_ty e; + bool simple; + asdl_seq *slices, *elts; + slices = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena); if (!slices) return NULL; for (j = 0; j < NCH(n); j += 2) { slc = ast_for_slice(c, CHILD(n, j)); if (!slc) return NULL; + if (slc->kind != Index_kind) + simple = false; asdl_seq_SET(slices, j / 2, slc); } - return Subscript(left_expr, ExtSlice(slices, c->c_arena), + if (!simple) { + return Subscript(left_expr, ExtSlice(slices, c->c_arena), + Load, LINENO(n), c->c_arena); + } + /* extract Index values and put them in a Tuple */ + elts = asdl_seq_new(asdl_seq_LEN(slices), c->c_arena); + for (j = 0; j < asdl_seq_LEN(slices); ++j) { + slc = (slice_ty)asdl_seq_GET(slices, j); + assert(slc->kind == Index_kind && slc->v.Index.value); + asdl_seq_SET(elts, j, slc->v.Index.value); + } + e = Tuple(elts, Load, LINENO(n), c->c_arena); + if (!e) + return NULL; + return Subscript(left_expr, Index(e, c->c_arena), Load, LINENO(n), c->c_arena); } } |