Improve macro to allow errors and fallthrough cases

Author: morr0ne

src/bin/mkdir.rs

@@ -1,40 +1,19 @@
-use std::io::{Write, stdout};
+use std::io::stdout;
 
-use coreutils::{Result, get_umask, help_text, version_text};
+use coreutils::{Result, cli, get_umask};
 use rustix::fs::{Mode, mkdir};
-use sap::{
-    Argument::{Long, Value},
-    Parser,
-};
-
-const VERSION: &str = version_text!("mkdir");
-const HELP: &str = help_text!("mkdir");
 
 fn main() -> Result {
     let mut stdout = stdout();
 
-    let mut arg_parser = Parser::from_env()?;
-
     let mut dirs = Vec::new();
 
-    while let Some(arg) = arg_parser.forward()? {
-        match arg {
-            Long("version") => {
-                stdout.write_all(VERSION.as_bytes())?;
-                stdout.flush()?;
-                return Ok(());
-            }
-            Long("help") => {
-                stdout.write_all(HELP.as_bytes())?;
-                stdout.flush()?;
-                return Ok(());
-            }
-            Value(value) => {
-                dirs.push(value.to_owned()); // FIXME: I am not a fan of all this allocation but we can't easily move out of arg_parser
-            }
-            argument => return Err(argument.into_error(None).into()),
+    cli! {
+        "mkdir", stdout, #error
+        Value(value) => {
+            dirs.push(value.to_owned()); // FIXME: I am not a fan of all this allocation but we can't easily move out of the argument parser
         }
-    }
+    };
 
     let mode = Mode::from_raw_mode(0o777) & !get_umask();
 

src/bin/uname.rs

@@ -22,7 +22,7 @@ fn main() -> Result {
     let mut stdout = stdout();
 
     cli! {
-        "uname", stdout, while,
+        "uname", stdout, #error
         Short('a') | Long("all") => {
             info_mask = Info::all();
         }
@@ -34,7 +34,6 @@ fn main() -> Result {
         Short('p') | Long("processor") => info_mask |= Info::PROCESSOR
         Short('i') | Long("hardware-platform") => info_mask |= Info::HARDWARE_PLATFORM
         Short('o') | Long("operating-system") => info_mask |= Info::OPERATING_SYSTEM
-        arg => return Err(arg.into_error(None).into())
     };
 
     if info_mask.is_empty() {

src/bin/whoami.rs

@@ -9,10 +9,7 @@ const CANNOT_FIND_UID: &[u8] = b"cannot find name for user ID: ";
 fn main() -> Result {
     let mut stdout = stdout();
 
-    cli! {
-        "whoami", stdout, if,
-        arg => return Err(arg.into_error(None).into())
-    };
+    cli! ("whoami", stdout, #error);
 
     let uid = geteuid();
 

src/bin/yes.rs

@@ -13,11 +13,10 @@ fn main() -> Result {
     let mut buffer: Option<Vec<u8>> = None;
 
     let arg_parser = cli! {
-        "yes", stdout, while,
+        "yes", stdout, #error
         Value(value) => {
             extend_buffer(&mut buffer, value.as_bytes().to_vec());
         }
-        arg => return Err(arg.into_error(None).into())
     };
 
     arg_parser

src/lib.rs

@@ -80,14 +80,14 @@ macro_rules! help_text {
 #[macro_export]
 #[doc(hidden)]
 macro_rules! _cli_impl {
-    ($name:literal, $stdout:ident, $loop_type:tt, $($item:pat => $matcher:expr)*) => {
+    ($name:literal, $stdout:ident, $($item:pat => $matcher:expr)*) => {
         {
             use std::io::Write;
             use sap::Argument::*;
 
             let mut arg_parser = sap::Parser::from_env()?;
 
-            $loop_type let Some(arg) = arg_parser.forward()? {
+            while let Some(arg) = arg_parser.forward()? {
                 match arg {
                     Long("version") => {
                         $stdout.write_all($crate::version_text!($name).as_bytes())?;
@@ -110,12 +110,16 @@ macro_rules! _cli_impl {
 
 #[macro_export]
 macro_rules! cli {
-    ($name:literal, $stdout:ident, while, $($item:pat => $matcher:expr)*) => {
-        $crate::_cli_impl!($name, $stdout, while, $($item => $matcher)*)
+    ($name:literal, $stdout:ident, $($item:pat => $matcher:expr)*) => {
+        $crate::_cli_impl!($name, $stdout, $($item => $matcher)*)
     };
 
-    ($name:literal, $stdout:ident, if, $($item:pat => $matcher:expr)*) => {
-        $crate::_cli_impl!($name, $stdout, if, $($item => $matcher)*)
+    ($name:literal, $stdout:ident, #fall $($item:pat => $matcher:expr)*) => {
+        $crate::_cli_impl!($name, $stdout, $($item => $matcher)* _ => {})
+    };
+
+    ($name:literal, $stdout:ident, #error $($item:pat => $matcher:expr)*) => {
+        $crate::_cli_impl!($name, $stdout, $($item => $matcher)* arg => return Err(arg.into_error(None).into()))
     };
 }