From 8b9d97cd64d872d5aeac82f6cd2fb44a501076d2 Mon Sep 17 00:00:00 2001
From: gwenn <gtreguier@gmail.com>
Date: Wed, 24 Aug 2016 20:34:39 +0200
Subject: [PATCH] Introduce longest_common_prefix function
---
src/completion.rs | 49 +++++++++++++++++++++++++++++++++++++++++++++++
src/lib.rs | 18 +++++++++++++++--
2 files changed, 65 insertions(+), 2 deletions(-)
diff --git a/src/completion.rs b/src/completion.rs
index 042c9873..0c9ebbd4 100644
--- a/src/completion.rs
+++ b/src/completion.rs
@@ -159,6 +159,33 @@ pub fn extract_word<'l>(line: &'l str,
}
}
+pub fn longest_common_prefix(candidates: &[String]) -> Option<String> {
+ if candidates.is_empty() {
+ return None;
+ } else if candidates.len() == 1 {
+ return Some(candidates[0].clone());
+ }
+ let mut longest_common_prefix = 0;
+ 'o: loop {
+ for i in 0..candidates.len() - 1 {
+ let b1 = candidates[i].as_bytes();
+ let b2 = candidates[i + 1].as_bytes();
+ if b1.len() <= longest_common_prefix || b2.len() <= longest_common_prefix ||
+ b1[i] != b2[i] {
+ break 'o;
+ }
+ }
+ longest_common_prefix += 1;
+ }
+ while !candidates[0].is_char_boundary(longest_common_prefix) {
+ longest_common_prefix -= 1;
+ }
+ if longest_common_prefix == 0 {
+ return None;
+ }
+ Some(String::from(&candidates[0][0..longest_common_prefix]))
+}
+
#[cfg(test)]
mod tests {
use std::collections::BTreeSet;
@@ -170,4 +197,26 @@ mod tests {
assert_eq!((4, "/usr/local/b"),
super::extract_word(line, line.len(), &break_chars));
}
+
+ #[test]
+ pub fn longest_common_prefix() {
+ let mut candidates = vec![];
+ let lcp = super::longest_common_prefix(&candidates);
+ assert!(lcp.is_none());
+
+ let c1 = String::from("User");
+ candidates.push(c1.clone());
+ let lcp = super::longest_common_prefix(&candidates);
+ assert_eq!(Some(c1.clone()), lcp);
+
+ let c2 = String::from("Users");
+ candidates.push(c2.clone());
+ let lcp = super::longest_common_prefix(&candidates);
+ assert_eq!(Some(c1), lcp);
+
+ let c3 = String::from("");
+ candidates.push(c3.clone());
+ let lcp = super::longest_common_prefix(&candidates);
+ assert!(lcp.is_none());
+ }
}
diff --git a/src/lib.rs b/src/lib.rs
index efcf868a..1dca7924 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -46,7 +46,7 @@ use std::sync::atomic;
#[cfg(unix)]
use nix::sys::signal;
-use completion::Completer;
+use completion::{Completer, longest_common_prefix};
use consts::KeyPress;
use history::History;
use line_buffer::{LineBuffer, MAX_LINE, WordAction};
@@ -587,9 +587,23 @@ fn complete_line<R: Read>(rdr: &mut tty::RawReader<R>,
}
}
Ok(Some(key))
- } else {
+ } else if CompletionMode::List == completion_mode {
+ // beep if ambiguous
+ if candidates.len() > 1 {
+ try!(beep());
+ }
+ if let Some(lcp) = longest_common_prefix(&candidates) {
+ // if we can extend the item, extend it and return to main loop
+ if lcp.len() > s.line.pos() - start {
+ completer.update(&mut s.line, start, &lcp);
+ try!(s.refresh_line());
+ return Ok(None);
+ }
+ }
// TODO ...
Ok(None)
+ } else {
+ Ok(None)
}
}
--
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