diff options
| -rw-r--r-- | lib/syntax_tools/src/erl_syntax.erl | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/lib/syntax_tools/src/erl_syntax.erl b/lib/syntax_tools/src/erl_syntax.erl index beae6f4a01..76a6a6dc36 100644 --- a/lib/syntax_tools/src/erl_syntax.erl +++ b/lib/syntax_tools/src/erl_syntax.erl @@ -2061,12 +2061,18 @@ revert_nil(Node) -> list_prefix(Node) -> case unwrap(Node) of - {cons, _, Head, _} -> - [Head]; + {cons, _, Head, Tail} -> + [Head | cons_prefix(Tail)]; Node1 -> (data(Node1))#list.prefix end. +%% collects sequences of conses; cf. cons_suffix/1 below +cons_prefix({cons, _, Head, Tail}) -> + [Head | cons_prefix(Tail)]; +cons_prefix(_) -> + []. + %% ===================================================================== %% @doc Returns the suffix subtree of a `list' node, if one @@ -2090,18 +2096,22 @@ list_prefix(Node) -> list_suffix(Node) -> case unwrap(Node) of {cons, _, _, Tail} -> - %% If there could be comments/annotations on the tail node, - %% we should not return `none' even if it has type `nil'. - case Tail of + case cons_suffix(Tail) of {nil, _} -> - none; % no interesting information is lost - _ -> - Tail + none; + Tail1 -> + Tail1 end; Node1 -> (data(Node1))#list.suffix end. +%% skips sequences of conses; cf. cons_prefix/1 above +cons_suffix({cons, _, _, Tail}) -> + cons_suffix(Tail); +cons_suffix(Tail) -> + Tail. + %% ===================================================================== %% @doc "Optimising" list skeleton cons operation. Creates an abstract |