Add --show command line flag

notes

@@ -1,6 +1,8 @@
 notes
 -----
 
+- fix --show to not print final newline, add a helper that iterates over
+  (item, first, last)
 - look through all justfiles for features of make that I use. so far:
   . phony
   . SHELL := zsh
@@ -11,7 +13,6 @@ notes
 
 command line arguments:
 - --show recipe: print recipe information
-- --list recipes if  a bad recipe given
 
 execution:
 - indent for line continuation

src/lib.rs

@@ -41,7 +41,7 @@ fn re(pattern: &str) -> Regex {
   Regex::new(pattern).unwrap()
 }
 
-struct Recipe<'a> {
+pub struct Recipe<'a> {
   line:               usize,
   name:               &'a str,
   leading_whitespace: &'a str,
@@ -49,6 +49,16 @@ struct Recipe<'a> {
   dependencies:       BTreeSet<&'a str>,
 }
 
+impl<'a> Display for Recipe<'a> {
+  fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+    try!(writeln!(f, "{}:", self.name));
+    for command in self.commands.iter() {
+      try!(writeln!(f, "    {}", command));
+    }
+    Ok(())
+  }
+}
+
 #[cfg(unix)]
 fn error_from_signal<'a>(recipe: &'a str, exit_status: process::ExitStatus) -> RunError<'a> {
   use std::os::unix::process::ExitStatusExt;
@@ -300,6 +310,10 @@ impl<'a> Justfile<'a> {
     }
     Ok(())
   }
+
+  pub fn get(&self, name: &str) -> Option<&Recipe<'a>> {
+    self.recipes.get(name)
+  }
 }
 
 #[derive(Debug)]

src/main.rs

@@ -29,6 +29,11 @@ fn main() {
          .short("l")
          .long("list")
          .help("Lists available recipes"))
+    .arg(Arg::with_name("show")
+         .short("s")
+         .long("show")
+         .takes_value(true)
+         .help("Show information about a recipe"))
     .arg(Arg::with_name("recipe")
          .multiple(true)
          .help("recipe(s) to run, defaults to the first recipe in the justfile"))
@@ -70,6 +75,16 @@ fn main() {
     std::process::exit(0);
   }
 
+  if let Some(name) = matches.value_of("show") {
+    match justfile.get(name) {
+      Some(recipe) => {
+        warn!("{}", recipe);
+        std::process::exit(0);
+      }
+      None => die!("justfile contains no recipe \"{}\"", name)
+    }
+  }
+
   let names = if let Some(names) = matches.values_of("recipe") {
     names.collect::<Vec<_>>()
   } else if let Some(name) = justfile.first() {