feat: add support for elvish shell (#1725)

* feat: add support for elvish shell

* improve doc

* elvish 0.15 is out

* fix example init

* update systax for 0.15 stable

* udpate second init example too

* remove warning from swift module

* add warning to status module docs

* prefix elvish version with v

2 files changed, 43 insertions, 0 deletions

diff --git a/src/init/mod.rs b/src/init/mod.rs
index f80e8aedc..e8ff73ce2 100644
--- a/src/init/mod.rs
+++ b/src/init/mod.rs
@@ -166,6 +166,13 @@ fi"#,
             let script = format!("eval $({} init ion --print-full-init)", starship.sprint()?);
             Some(script)
         }
+        Some("elvish") => {
+            let script = format!(
+                "eval ({} init elvish --print-full-init | slurp)",
+                starship.sprint_posix()?
+            );
+            Some(script)
+        }
         None => {
             println!(
                 "Invalid shell name provided: {}\\n\
@@ -204,6 +211,7 @@ pub fn init_main(shell_name: &str) -> io::Result<()> {
         "fish" => print_script(FISH_INIT, &starship_path.sprint_posix()?),
         "powershell" => print_script(PWSH_INIT, &starship_path.sprint()?),
         "ion" => print_script(ION_INIT, &starship_path.sprint()?),
+        "elvish" => print_script(ELVISH_INIT, &starship_path.sprint_posix()?),
         _ => {
             println!(
                 "printf \"Shell name detection failed on phase two init.\\n\
@@ -245,3 +253,5 @@ const FISH_INIT: &str = include_str!("starship.fish");
 const PWSH_INIT: &str = include_str!("starship.ps1");
 
 const ION_INIT: &str = include_str!("starship.ion");
+
+const ELVISH_INIT: &str = include_str!("starship.elv");
diff --git a/src/init/starship.elv b/src/init/starship.elv
new file mode 100644
index 000000000..1b84632a8
--- /dev/null
+++ b/src/init/starship.elv
@@ -0,0 +1,33 @@
+set-env STARSHIP_SHELL "elvish"
+set-env STARSHIP_SESSION_KEY (::STARSHIP:: session)
+
+# Define Hooks
+local:cmd-start-time = 0
+local:cmd-end-time = 0
+
+fn starship-after-readline-hook [line]{
+    cmd-start-time = (::STARSHIP:: time)
+}
+
+fn starship-before-readline-hook {
+    cmd-end-time = (::STARSHIP:: time)
+}
+
+# Install Hooks
+edit:after-readline = [ $@edit:after-readline $starship-after-readline-hook~ ]
+edit:before-readline = [ $@edit:before-readline $starship-before-readline-hook~ ]
+
+# Install starship
+edit:prompt = {
+    # Note:
+    # Elvish does not appear to support exit status codes (--status)
+
+    if (== $cmd-start-time 0) {
+        ::STARSHIP:: prompt --jobs=$num-bg-jobs
+    } else {
+        ::STARSHIP:: prompt --jobs=$num-bg-jobs --cmd-duration=(- $cmd-end-time $cmd-start-time)
+    }
+}
+
+# Get rid of default rprompt
+edit:rprompt = { }