add CLI option to identify a command with a custom name

CLI option `--name` can be used to define the name to identify a
command. If not passed, then the command itself is used. Commands
and names are paired in the same order: The first command executed gets
the first name passed as option.

Close #326

src/hyperfine/app.rs

@@ -226,6 +226,16 @@ fn build_app() -> App<'static, 'static> {
                      when trying to benchmark output speed.",
                 ),
         )
+        .arg(
+            Arg::with_name("command-name")
+                .long("name")
+                .short("n")
+                .takes_value(true)
+                .multiple(true)
+                .number_of_values(1)
+                .value_name("NAME")
+                .help("Give a meaningful name to a command"),
+        )
         .help_message("Print this help message.")
         .version_message("Show version information.")
 }

src/hyperfine/benchmark.rs

@@ -202,12 +202,20 @@ pub fn run_benchmark(
     shell_spawning_time: TimingResult,
     options: &HyperfineOptions,
 ) -> io::Result<BenchmarkResult> {
+    let shell_cmd = cmd.get_shell_command();
+    let command_name = if let Some(names) = &options.names {
+        names.get(num).unwrap_or(&shell_cmd)
+    } else {
+        &shell_cmd
+    };
+    let command_name = command_name.to_string();
+
     if options.output_style != OutputStyleOption::Disabled {
         println!(
             "{}{}: {}",
             "Benchmark #".bold(),
             (num + 1).to_string().bold(),
-            cmd
+            &command_name
         );
     }
 
@@ -415,7 +423,7 @@ pub fn run_benchmark(
     run_cleanup_command(&options.shell, &cleanup_cmd, options.show_output)?;
 
     Ok(BenchmarkResult::new(
-        cmd.get_shell_command(),
+        command_name,
         t_mean,
         t_stddev,
         t_median,

src/hyperfine/types.rs

@@ -210,11 +210,14 @@ pub struct HyperfineOptions {
 
     /// Which time unit to use for CLI & Markdown output
     pub time_unit: Option<Unit>,
+
+    pub names: Option<Vec<String>>,
 }
 
 impl Default for HyperfineOptions {
     fn default() -> HyperfineOptions {
         HyperfineOptions {
+            names: None,
             warmup_count: 0,
             runs: Runs::default(),
             min_time_sec: 3.0,

src/main.rs

@@ -127,6 +127,10 @@ fn build_hyperfine_options(matches: &ArgMatches<'_>) -> Result<HyperfineOptions,
         (None, None) => {}
     };
 
+    options.names = matches
+        .values_of("command-name")
+        .map(|values| values.map(String::from).collect::<Vec<String>>());
+
     options.preparation_command = matches
         .values_of("prepare")
         .map(|values| values.map(String::from).collect::<Vec<String>>());