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perf: replace list length-checks with pattern matching #128

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Merged
mhanberg merged 1 commit into from
Apr 23, 2026
Merged

perf: replace list length-checks with pattern matching #128

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21 changes: 13 additions & 8 deletions lib/spitfire.ex
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Original file line number Diff line number Diff line change
Expand Up @@ -964,16 +964,21 @@ defmodule Spitfire do
defp invalid_assoc_call_meta?([_entry | meta]), do: invalid_assoc_call_meta?(meta)

defp invalid_assoc_key_in_map?({name, meta, args}) when is_atom(name) and is_list(meta) and is_list(args) do
arity = length(args)
case args do
[_, _ | _] ->
arity = length(args)
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@katafrakt katafrakt Apr 15, 2026

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We still need arity here to pass to Macro.operator? and Macro.special_form?, but we calculate it only if we know it's more than one.


arity > 1 and
not Macro.operator?(name, arity) and
not Macro.special_form?(name, arity) and
invalid_assoc_call_meta?(meta)
not Macro.operator?(name, arity) and
not Macro.special_form?(name, arity) and
invalid_assoc_call_meta?(meta)

_ ->
false
end
end

defp invalid_assoc_key_in_map?({{:., _, [_lhs, _rhs]}, meta, args}) when is_list(meta) and is_list(args) do
length(args) > 1 and invalid_assoc_call_meta?(meta)
match?([_, _ | _], args) and invalid_assoc_call_meta?(meta)
end

defp invalid_assoc_key_in_map?({{name, meta, args}, _value}) when is_atom(name) and is_list(meta) and is_list(args) do
Expand Down Expand Up @@ -3196,7 +3201,7 @@ defmodule Spitfire do
{Enum.reverse(pairs), parser}
end

if length(pairs) == 2 do
if match?([_, _], pairs) do
tuple = encode_literal(parser, pairs |> List.wrap() |> List.to_tuple(), orig_meta)
parser = Map.put(parser, :nesting, old_nesting)
{tuple, parser}
Expand Down Expand Up @@ -3418,7 +3423,7 @@ defmodule Spitfire do

true ->
meta =
if identifier == :op_identifier && length(args) == 1 do
if identifier == :op_identifier && match?([_], args) do
[{:ambiguous_op, nil} | meta]
else
meta
Expand Down
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