erlang and js

gleam-lang · Oct 21, 2024 · 3c61469 · 3c61469
1 parent d380a57
commit 3c61469
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Showing 19 changed files with 2,396 additions and 793 deletions.
diff --git a/compiler-core/src/erlang.rs b/compiler-core/src/erlang.rs
@@ -46,6 +46,7 @@ struct Env<'a> {
     module: &'a str,
     function: &'a str,
     line_numbers: &'a LineNumbers,
+    echo_used: bool,
     current_scope_vars: im::HashMap<String, usize>,
     erl_function_scope_vars: im::HashMap<String, usize>,
 }
@@ -56,6 +57,7 @@ impl<'env> Env<'env> {
         Self {
             current_scope_vars: vars.clone(),
             erl_function_scope_vars: vars,
+            echo_used: false,
             line_numbers,
             function,
             module,
@@ -217,21 +219,35 @@ fn module_document<'a>(
 
     let src_path = EcoString::from(module.type_info.src_path.as_str());
 
-    let statements = join(
-        module
-            .definitions
-            .iter()
-            .flat_map(|s| module_statement(s, &module.name, line_numbers, &src_path)),
+    let mut echo_used = false;
+    let mut statements = Vec::with_capacity(module.definitions.len());
+    for definition in module.definitions.iter() {
+        if let Some((statement_document, env)) =
+            module_statement(definition, &module.name, line_numbers, &src_path)
+        {
+            echo_used = echo_used || env.echo_used;
+            statements.push(statement_document);
+        }
+    }
+
+    let module = docvec![
+        header,
+        "-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).",
         lines(2),
-    );
+        exports,
+        type_defs,
+        join(statements, lines(2)),
+    ];
 
-    Ok(header
-        .append("-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).")
-        .append(lines(2))
-        .append(exports)
-        .append(type_defs)
-        .append(statements)
-        .append(line()))
+    let module = if echo_used {
+        module
+            .append(lines(2))
+            .append(std::include_str!("../templates/echo.erl").to_doc())
+    } else {
+        module
+    };
+
+    Ok(module.append(line()))
 }
 
 fn register_imports(
@@ -354,7 +370,7 @@ fn module_statement<'a>(
     module: &'a str,
     line_numbers: &'a LineNumbers,
     src_path: &EcoString,
-) -> Option<Document<'a>> {
+) -> Option<(Document<'a>, Env<'a>)> {
     match statement {
         Definition::TypeAlias(TypeAlias { .. })
         | Definition::CustomType(CustomType { .. })
@@ -372,7 +388,7 @@ fn module_function<'a>(
     module: &'a str,
     line_numbers: &'a LineNumbers,
     src_path: EcoString,
-) -> Option<Document<'a>> {
+) -> Option<(Document<'a>, Env<'a>)> {
     // Private external functions don't need to render anything, the underlying
     // Erlang implementation is used directly at the call site.
     if function.external_erlang.is_some() && function.publicity.is_private() {
@@ -424,16 +440,19 @@ fn module_function<'a>(
         })
         .unwrap_or_else(|| statement_sequence(&function.body, &mut env));
 
-    Some(docvec![
-        file_attribute,
-        line(),
-        spec,
-        atom_string(escape_erlang_existing_name(function_name).to_string()),
-        arguments,
-        " ->",
-        line().append(body).nest(INDENT).group(),
-        ".",
-    ])
+    Some((
+        docvec![
+            file_attribute,
+            line(),
+            spec,
+            atom_string(escape_erlang_existing_name(function_name).to_string()),
+            arguments,
+            " ->",
+            line().append(body).nest(INDENT).group(),
+            ".",
+        ],
+        env,
+    ))
 }
 
 fn file_attribute<'a>(
@@ -1738,7 +1757,8 @@ fn panic<'a>(location: SrcSpan, message: Option<&'a TypedExpr>, env: &mut Env<'a
 }
 
 fn echo<'a>(body: Document<'a>, env: &mut Env<'a>) -> Document<'a> {
-    module_fn_with_args("mmmh", "echo", vec![body], env)
+    env.echo_used = true;
+    "echo".to_doc().append(wrap_args(vec![body]))
 }
 
 fn erlang_error<'a>(

diff --git a/...-core/src/erlang/tests/snapshots/gleam_core__erlang__tests__echo__echo_in_a_pipeline.snap b/...-core/src/erlang/tests/snapshots/gleam_core__erlang__tests__echo__echo_in_a_pipeline.snap
@@ -16,5 +16,177 @@ wibble(N) ->
 -spec main() -> list(integer()).
 main() ->
     _pipe = [1, 2, 3],
-    mmmh:echo(_pipe),
+    echo(_pipe),
     wibble(_pipe).
+
+-define(is_lowercase_char(X), (X > 96 andalso X < 123)).
+-define(is_underscore_char(X), (X == 95)).
+-define(is_digit_char(X), (X > 47 andalso X < 58)).
+-define(could_be_record(Tuple),
+    is_tuple(Tuple) andalso
+        is_atom(element(1, Tuple)) andalso
+        element(1, Tuple) =/= false andalso
+        element(1, Tuple) =/= true andalso
+        element(1, Tuple) =/= nil
+).
+-define(is_atom_char(C),
+    (?is_lowercase_char(C) orelse
+        ?is_underscore_char(C) orelse
+        ?is_digit_char(C))
+).
+
+echo(Value) ->
+    String = echo@inspect(Value),
+    io:put_chars(standard_error, [String, $\n]),
+    Value.
+
+echo@inspect(Value) ->
+    case Value of
+        nil -> "Nil";
+        true -> "True";
+        false -> "False";
+        Int when is_integer(Int) -> erlang:integer_to_list(Int);
+        Float when is_float(Float) -> io_lib_format:fwrite_g(Float);
+        Bits when is_bitstring(Bits) -> inspect@bit_array(Bits);
+        Binary when is_binary(Binary) -> inspect@binary(Binary);
+        Atom when is_atom(Atom) -> inspect@atom(Atom);
+        List when is_list(List) -> inspect@list(List);
+        Map when is_map(Map) -> inspect@map(Map);
+        Record when ?could_be_record(Record) -> inspect@record(Record);
+        Tuple when is_tuple(Tuple) -> inspect@tuple(Tuple);
+        Function when is_function(Function) -> inspect@function(Function);
+        Any -> ["//erl(", io_lib:format("~p", [Any]), ")"]
+    end.
+
+inspect@bit_array(Bits) ->
+    Pieces = inspect@bit_array_pieces(Bits, []),
+    Inner = string:join(lists:reverse(Pieces), <<", ">>),
+    <<"<<", Inner/binary, ">>">>.
+
+inspect@bit_array_pieces(Bits, Acc) ->
+    case Bits of
+        <<>> ->
+            Acc;
+        <<Byte, Rest/bitstring>> ->
+            inspect@bit_array_pieces(Rest, [integer_to_binary(Byte) | Acc]);
+        _ ->
+            Size = bit_size(Bits),
+            <<RemainingBits:Size>> = Bits,
+            SizeString = <<":size(", (integer_to_binary(Size)), ")">>,
+            Piece = <<(integer_to_binary(RemainingBits)), SizeString>>,
+            inspect@bit_array_pieces(<<>>, [Piece | Acc])
+    end.
+
+inspect@binary(Binary) ->
+    case inspect@maybe_utf8_string(Binary, <<>>) of
+        {ok, InspectedUtf8String} ->
+            InspectedUtf8String;
+        {error, not_a_utf8_string} ->
+            Segments = [integer_to_list(X) || <<X>> <= Binary],
+            ["<<", lists:join(", ", Segments), ">>"]
+    end.
+
+inspect@atom(Atom) ->
+    Binary = erlang:atom_to_binary(Atom),
+    case inspect@maybe_gleam_atom(Binary, none, <<>>) of
+        {ok, Inspected} -> Inspected;
+        {error, _} -> ["atom.create_from_string(\"", Binary, "\")"]
+    end.
+
+inspect@list(List) ->
+    case inspect@proper_or_improper_list(List) of
+        {proper, Elements} -> ["[", Elements, "]"];
+        {improper, Elements} -> ["//erl([", Elements, "])"]
+    end.
+
+inspect@map(Map) ->
+    Fields = [
+        [<<"#(">>, echo@inspect(Key), <<", ">>, echo@inspect(Value), <<")">>]
+     || {Key, Value} <- maps:to_list(Map)
+    ],
+    ["dict.from_list([", lists:join(", ", Fields), "])"].
+
+inspect@record(Record) ->
+    [Atom | ArgsList] = erlang:tuple_to_list(Record),
+    Args = lists:join(", ", lists:map(fun echo@inspect/1, ArgsList)),
+    [echo@inspect(Atom), "(", Args, ")"].
+
+inspect@tuple(Tuple) ->
+    Elements = lists:map(fun echo@inspect/1, erlang:tuple_to_list(Tuple)),
+    ["#(", lists:join(", ", Elements), ")"].
+
+inspect@function(Function) ->
+    {arity, Arity} = erlang:fun_info(Function, arity),
+    ArgsAsciiCodes = lists:seq($a, $a + Arity - 1),
+    Args = lists:join(", ", lists:map(fun(Arg) -> <<Arg>> end, ArgsAsciiCodes)),
+    ["//fn(", Args, ") { ... }"].
+
+inspect@maybe_utf8_string(Binary, Acc) ->
+    case Binary of
+        <<>> ->
+            {ok, <<$", Acc/binary, $">>};
+        <<First/utf8, Rest/binary>> ->
+            Escaped = inspect@escape_grapheme(First),
+            inspect@maybe_utf8_string(Rest, <<Acc/binary, Escaped/binary>>);
+        _ ->
+            {error, not_a_utf8_string}
+    end.
+
+inspect@escape_grapheme(Char) ->
+    case Char of
+        $" -> <<$\\, $">>;
+        $\\ -> <<$\\, $\\>>;
+        $\r -> <<$\\, $r>>;
+        $\n -> <<$\\, $n>>;
+        $\t -> <<$\\, $t>>;
+        $\f -> <<$\\, $f>>;
+        X when X > 126, X < 160 -> inspect@convert_to_u(X);
+        X when X < 32 -> inspect@convert_to_u(X);
+        Other -> <<Other/utf8>>
+    end.
+
+inspect@convert_to_u(Code) ->
+    list_to_binary(io_lib:format("\\u{~4.16.0B}", [Code])).
+
+inspect@proper_or_improper_list(List) ->
+    case List of
+        [] ->
+            {proper, []};
+        [First] ->
+            {proper, [echo@inspect(First)]};
+        [First | Rest] when is_list(Rest) ->
+            {Kind, Inspected} = inspect@list(Rest),
+            {Kind, [echo@inspect(First), ", " | Inspected]};
+        [First | ImproperRest] ->
+            {improper, [echo@inspect(First), " | ", echo@inspect(ImproperRest)]}
+    end.
+
+inspect@maybe_gleam_atom(Atom, PrevChar, Acc) ->
+    case {Atom, PrevChar} of
+        {<<>>, none} ->
+            {error, nil};
+        {<<First, _/binary>>, none} when ?is_digit_char(First) ->
+            {error, nil};
+        {<<"_", _/binary>>, none} ->
+            {error, nil};
+        {<<"_">>, _} ->
+            {error, nil};
+        {<<"_", _/binary>>, $_} ->
+            {error, nil};
+        {<<First, _/binary>>, _} when not ?is_atom_char(First) ->
+            {error, nil};
+        {<<First, Rest/binary>>, none} ->
+            inspect@maybe_gleam_atom(Rest, First, <<Acc, (inspect@uppercase(First))>>);
+        {<<"_", Rest/binary>>, _} ->
+            inspect@maybe_gleam_atom(Rest, $_, Acc);
+        {<<First, Rest/binary>>, $_} ->
+            inspect@maybe_gleam_atom(Rest, First, <<Acc, (inspect@uppercase(First))>>);
+        {<<First, Rest/binary>>, _} ->
+            inspect@maybe_gleam_atom(Rest, First, <<Acc, First>>);
+        {<<>>, _} ->
+            {ok, Acc};
+        _ ->
+            throw({gleam_error, echo, Atom, PrevChar, Acc})
+    end.
+
+inspect@uppercase(X) -> X - 32.