Convert to zero args

build.roc

@@ -15,16 +15,16 @@ import cli.Env
 main! : _ => Result {} _
 main! = |_args|
 
-    roc_cmd = Env.var!("ROC") |> Result.with_default("roc")
+    roc_cmd = Env.var!("ROC") ?? "roc"
 
     debug_mode =
         when Env.var!("DEBUG") is
-            Ok(str) if !(Str.is_empty(str)) -> Debug
+            Ok(str) if !Str.is_empty(str) -> Debug
             _ -> Release
 
     roc_version!(roc_cmd)?
 
-    os_and_arch = get_os_and_arch!({})?
+    os_and_arch = get_os_and_arch!()?
 
     stub_lib_path = "platform/libapp.${stub_file_extension(os_and_arch)}"
 
@@ -49,11 +49,11 @@ roc_version! = |roc_cmd|
     Cmd.exec!(roc_cmd, ["version"])
     |> Result.map_err(RocVersionCheckFailed)
 
-get_os_and_arch! : {} => Result OSAndArch _
-get_os_and_arch! = |{}|
+get_os_and_arch! : () => Result OSAndArch _
+get_os_and_arch! = ||
     info!("Getting the native operating system and architecture ...")?
 
-    convert_os_and_arch!(Env.platform!({}))
+    convert_os_and_arch!(Env.platform!())
 
 OSAndArch : [
     MacosArm64,
@@ -117,7 +117,7 @@ get_rust_target_folder! = |debug_mode|
 cargo_build_host! : [Debug, Release] => Result {} _
 cargo_build_host! = |debug_mode|
 
-    cargo_build_args! = |{}|
+    cargo_build_args! = ||
         when debug_mode is
             Debug ->
                 info!("Building rust host in debug mode...")?
@@ -127,7 +127,7 @@ cargo_build_host! = |debug_mode|
                 info!("Building rust host ...")?
                 Ok(["build", "--release"])
 
-    args = cargo_build_args!({})?
+    args = cargo_build_args!()?
 
     Cmd.exec!("cargo", args)
     |> Result.map_err(ErrBuildingHostBinaries)

examples/command.roc

@@ -6,21 +6,22 @@ import pf.Stdout
 import pf.Cmd
 
 main! = |_args|
-    status_example!({})?
+    status_example!()?
 
-    output_example!({})?
+    output_example!()?
 
-    exec_example!({})?
+    exec_example!()?
 
     Ok({})
 
-exec_example! : {} => Result {} _
-exec_example! = |{}| Cmd.exec!("echo", ["EXEC"])
+exec_example! : () => Result {} _
+exec_example! = ||
+    Cmd.exec!("echo", ["EXEC"])
 
 # Run "env" with verbose option, clear all environment variables, and pass in
 # "FOO" and "BAZ".
-status_example! : {} => Result {} _
-status_example! = |{}|
+status_example! : () => Result {} _
+status_example! = ||
     result =
         Cmd.new("env")
         |> Cmd.arg("-v")
@@ -35,8 +36,8 @@ status_example! = |{}|
 
 # Run "env" with verbose option, clear all environment variables, and pass in
 # only as an environment variable "FOO"
-output_example! : {} => Result {} _
-output_example! = |{}|
+output_example! : () => Result {} _
+output_example! = ||
 
     output =
         Cmd.new("env")
@@ -45,6 +46,6 @@ output_example! = |{}|
         |> Cmd.args(["-v"])
         |> Cmd.output!
 
-    msg = Str.from_utf8(output.stdout) |> Result.with_default("Failed to decode stdout")
+    msg = Str.from_utf8(output.stdout) ?? "Failed to decode stdout"
 
     Stdout.write!(msg)

examples/countdown.roc

@@ -7,14 +7,14 @@ import pf.Stdout
 
 main! = |_args|
     Stdout.line!("\nLet's count down from 3 together - all you have to do is press <ENTER>.")?
-    _ = Stdin.line!({})
+    _ = Stdin.line!()
     tick!(3)
 
 tick! = |n|
     if n == 0 then
         Stdout.line!("🎉 SURPRISE! Happy Birthday! 🎂")?
         Ok({})
     else
-        Stdout.line!("${Num.to_str n}...")?
-        _ = Stdin.line!({})
+        Stdout.line!("${Num.to_str(n)}...")?
+        _ = Stdin.line!()
         tick!(n - 1)

examples/echo.roc

@@ -7,14 +7,14 @@ import pf.Stdout
 
 main! = |_args|
     Stdout.line!("Shout into this cave and hear the echo!")?
-    tick!({})
+    tick!()
 
-tick! : {} => Result {} [StdoutErr _]
-tick! = |{}|
-    when Stdin.line!({}) is
+tick! : () => Result {} [StdoutErr _]
+tick! = ||
+    when Stdin.line!() is
         Ok(str) ->
             Stdout.line!(echo(str))?
-            tick!({})
+            tick!()
 
         Err(EndOfFile) ->
             Stdout.line!(echo("Received end of input (EOF)."))?
@@ -32,10 +32,10 @@ echo = |shout|
     |> Str.to_utf8
     |> List.map_with_index(
         |_, i|
-            length = (List.len(Str.to_utf8(shout)) - i)
-            phrase = (List.split_at(Str.to_utf8(shout), length)).before
+            length = List.len(Str.to_utf8(shout)) - i
+            { before: phrase} = List.split_at(Str.to_utf8(shout), length)
 
-            List.concat(silence((if i == 0 then 2 * length else length)), phrase),
+            List.concat(silence(if i == 0 then 2 * length else length), phrase),
     )
     |> List.join
     |> Str.from_utf8

examples/file-mixed.roc

@@ -11,9 +11,9 @@ import pf.Dir
 
 out_txt_path = "out.txt"
 
-task! = |{}|
+task! = ||
 
-    cwd_str = Path.display(Env.cwd!({})?)
+    cwd_str = Path.display(Env.cwd!()?)
 
     Stdout.line!("cwd: ${cwd_str}")?
 
@@ -34,7 +34,7 @@ task! = |{}|
     Ok({})
 
 main! = |_args|
-    when task!({}) is
+    when task!() is
         Ok({}) -> Stdout.line!("Successfully wrote a string to out.txt")
         Err(err) ->
             msg =

examples/file-read.roc

@@ -7,7 +7,7 @@ import pf.File
 
 main! = |_args|
 
-    run!({})
+    run!()
     ? |err|
         msg =
             when err is
@@ -21,9 +21,9 @@ main! = |_args|
 
     Ok({})
 
-run! = |{}|
+run! = ||
     file_name = "LICENSE"
     contents = File.read_utf8!(file_name)?
     lines = Str.split_on(contents, "\n")
 
-    Stdout.line!(Str.concat("First line of ${file_name}: ", (List.first(lines) |> Result.with_default("err"))))
+    Stdout.line!(Str.concat("First line of ${file_name}: ", List.first(lines) ?? "err"))

examples/form.roc

@@ -9,10 +9,10 @@ main! = |_args|
 
     Stdout.line!("What's your first name?")?
 
-    first = Stdin.line!({})?
+    first = Stdin.line!()?
 
     Stdout.line!("What's your last name?")?
 
-    last = Stdin.line!({})?
+    last = Stdin.line!()?
 
     Stdout.line!("Hi, ${first} ${last}! 👋")

examples/piping.roc

@@ -11,6 +11,6 @@ main! = |_args|
     Stdout.line!("I read ${Num.to_str(lines)} lines from stdin.")
 
 count! = |n|
-    when Stdin.line!({}) is
-        Ok(_) -> count!((n + 1))
+    when Stdin.line!() is
+        Ok(_) -> count!(n + 1)
         Err(_) -> n

examples/stdin.roc

@@ -9,7 +9,7 @@ import pf.Stdin
 main! = |_args|
     Stdout.line!("Enter a series of number characters (0-9):")?
 
-    number_bytes = take_number_bytes!({})?
+    number_bytes = take_number_bytes!()?
 
     if List.is_empty(number_bytes) then
         Stderr.line!("Expected a series of number characters (0-9)")
@@ -21,9 +21,9 @@ main! = |_args|
             Err(_) ->
                 Stderr.line!("Error, bad utf8")
 
-take_number_bytes! : {} => Result (List U8) _
-take_number_bytes! = |{}|
-    bytes_read = Stdin.bytes!({})?
+take_number_bytes! : () => Result (List U8) _
+take_number_bytes! = ||
+    bytes_read = Stdin.bytes!()?
 
     number_bytes =
         List.walk(

examples/tcp-client.roc

@@ -8,7 +8,7 @@ import pf.Stderr
 # To run this example: check the README.md in this folder
 
 main! = |_args|
-    when run!({}) is
+    when run!() is
         Ok({}) -> Ok({})
         Err(err) -> handle_err!(err)
 
@@ -42,8 +42,8 @@ handle_err! = |error|
 
         other -> Stderr.line!("Got other error: ${Inspect.to_str(other)}")
 
-run! : {} => Result {} _
-run! = |{}|
+run! : () => Result {} _
+run! = ||
 
     stream = Tcp.connect!("127.0.0.1", 8085)?
 
@@ -58,7 +58,7 @@ tick! : Tcp.Stream => Result {} _
 tick! = |stream|
     Stdout.write!("> ")?
 
-    out_msg = Stdin.line!({})?
+    out_msg = Stdin.line!()?
 
     Tcp.write_utf8!(stream, "${out_msg}\n")?
 

examples/temp-dir.roc

@@ -12,7 +12,7 @@ import pf.Path
 ## for example: `roc build examples/temp-dir.roc --linker=legacy`
 main! = |_args|
 
-    temp_dir_str = Path.display(Env.temp_dir!({}))
+    temp_dir_str = Path.display(Env.temp_dir!())
 
     Stdout.line!("The temp dir path is ${temp_dir_str}")
     |> Result.map_err(|err| Exit(1, "Failed to print temp dir:\n\t${Inspect.to_str(err)}"))

examples/time.roc

@@ -7,11 +7,11 @@ import pf.Sleep
 # To run this example: check the README.md in this folder
 
 main! = |_args|
-    start = Utc.now!({})
+    start = Utc.now!()
 
     Sleep.millis!(1500)
 
-    finish = Utc.now!({})
+    finish = Utc.now!()
 
     duration = Num.to_str(Utc.delta_as_nanos(start, finish))
 

platform/Env.roc

@@ -16,9 +16,9 @@ import Host
 
 ## Reads the [current working directory](https://en.wikipedia.org/wiki/Working_directory)
 ## from the environment. File operations on relative [Path]s are relative to this directory.
-cwd! : {} => Result Path [CwdUnavailable]
-cwd! = |{}|
-    bytes = Host.cwd!({}) |> Result.with_default([])
+cwd! : () => Result Path [CwdUnavailable]
+cwd! = ||
+    bytes = Host.cwd!() ?? []
 
     if List.is_empty(bytes) then
         Err(CwdUnavailable)
@@ -30,13 +30,12 @@ cwd! = |{}|
 ## to this directory.
 set_cwd! : Path => Result {} [InvalidCwd]
 set_cwd! = |path|
-    Host.set_cwd!(InternalPath.to_bytes(path))
-    |> Result.map_err(|{}| InvalidCwd)
+    Host.set_cwd!(InternalPath.to_bytes(path)) |> Result.map_err(|_| InvalidCwd)
 
 ## Gets the path to the currently-running executable.
-exe_path! : {} => Result Path [ExePathUnavailable]
-exe_path! = |{}|
-    when Host.exe_path!({}) is
+exe_path! : () => Result Path [ExePathUnavailable]
+exe_path! = ||
+    when Host.exe_path!() is
         Ok(bytes) -> Ok(InternalPath.from_os_bytes(bytes))
         Err({}) -> Err(ExePathUnavailable)
 
@@ -46,8 +45,7 @@ exe_path! = |{}|
 ## [Unicode replacement character](https://unicode.org/glossary/#replacement_character) ('�').
 var! : Str => Result Str [VarNotFound]
 var! = |name|
-    Host.env_var!(name)
-    |> Result.map_err(|{}| VarNotFound)
+    Host.env_var!(name) |> Result.map_err(|_| VarNotFound)
 
 ## Reads the given environment variable and attempts to decode it.
 ##
@@ -81,17 +79,16 @@ decode! = |name|
         Err({}) -> Err(VarNotFound)
         Ok(var_str) ->
             Str.to_utf8(var_str)
-            |> Decode.from_bytes(EnvDecoding.format({}))
+            |> Decode.from_bytes(EnvDecoding.format())
             |> Result.map_err(|_| DecodeErr(TooShort))
 
 ## Reads all the process's environment variables into a [Dict].
 ##
 ## If any key or value contains invalid Unicode, the [Unicode replacement character](https://unicode.org/glossary/#replacement_character)
 ## will be used in place of any parts of keys or values that are invalid Unicode.
-dict! : {} => Dict Str Str
-dict! = |{}|
-    Host.env_dict!({})
-    |> Dict.from_list
+dict! : () => Dict Str Str
+dict! = ||
+    Dict.from_list(Host.env_dict!())
 
 # ## Walks over the process's environment variables as key-value arguments to the walking function.
 # ##
@@ -135,10 +132,10 @@ OS : [LINUX, MACOS, WINDOWS, OTHER Str]
 ##
 ## Note these values are constants from when the platform is built.
 ##
-platform! : {} => { arch : ARCH, os : OS }
-platform! = |{}|
+platform! : () => { arch : ARCH, os : OS }
+platform! = ||
 
-    from_rust = Host.current_arch_os!({})
+    from_rust = Host.current_arch_os!()
 
     arch =
         when from_rust.arch is
@@ -166,7 +163,6 @@ platform! = |{}|
 ## to create a uniquely named file. Creating a file or directory with a fixed or predictable name may
 ## result in “insecure temporary file” security vulnerabilities.
 ##
-temp_dir! : {} => Path
-temp_dir! = |{}|
-    Host.temp_dir!({})
-    |> InternalPath.from_os_bytes
+temp_dir! : () => Path
+temp_dir! = ||
+    InternalPath.from_os_bytes(Host.temp_dir!())

platform/EnvDecoding.roc

@@ -26,8 +26,8 @@ EnvFormat := {} implements [
         },
     ]
 
-format : {} -> EnvFormat
-format = |{}| @EnvFormat({})
+format : () -> EnvFormat
+format = || @EnvFormat({})
 
 decode_bytes_to_num = |bytes, transformer|
     when Str.from_utf8(bytes) is