refactor completion and signature help using hooks

helix-stdx/Cargo.toml

@@ -14,6 +14,7 @@ homepage.workspace = true
 [dependencies]
 dunce = "1.0"
 etcetera = "0.8"
+ropey = { version = "1.6.1", default-features = false }
 
 [dev-dependencies]
 tempfile = "3.9"

helix-stdx/src/lib.rs

@@ -1,2 +1,3 @@
 pub mod env;
 pub mod path;
+pub mod rope;

helix-stdx/src/rope.rs

@@ -0,0 +1,26 @@
+use ropey::RopeSlice;
+
+pub trait RopeSliceExt: Sized {
+    fn ends_with(self, text: &str) -> bool;
+    fn starts_with(self, text: &str) -> bool;
+}
+
+impl RopeSliceExt for RopeSlice<'_> {
+    fn ends_with(self, text: &str) -> bool {
+        let len = self.len_bytes();
+        if len < text.len() {
+            return false;
+        }
+        self.get_byte_slice(len - text.len()..)
+            .map_or(false, |end| end == text)
+    }
+
+    fn starts_with(self, text: &str) -> bool {
+        let len = self.len_bytes();
+        if len < text.len() {
+            return false;
+        }
+        self.get_byte_slice(..len - text.len())
+            .map_or(false, |start| start == text)
+    }
+}