Refactor highlighting

.github/workflows/rust.yml

@@ -48,6 +48,13 @@ jobs:
         run: cargo check --workspace --no-default-features
         env:
           RUSTFLAGS: "-D warnings"
+      - name: Check split-highlight feature
+        run: |
+          cargo check --workspace --all-targets --features 'split-highlight'
+          cargo check --workspace --all-targets --features 'split-highlight ansi-str'
+          cargo check --workspace --all-targets --features 'split-highlight anstyle'
+          cargo check --workspace --all-targets --features 'split-highlight ansi-str derive'
+          cargo check --workspace --all-targets --features 'split-highlight anstyle derive'
 
   direct-minimal-versions:
     name: Test min versions

Cargo.toml

@@ -11,10 +11,7 @@ keywords = ["readline"]
 license = "MIT"
 categories = ["command-line-interface"]
 
-exclude = [
-  "/.github/*",
-  "/rustfmt.toml",
-]
+exclude = ["/.github/*", "/rustfmt.toml"]
 
 [badges]
 maintenance = { status = "actively-developed" }
@@ -23,6 +20,10 @@ maintenance = { status = "actively-developed" }
 members = ["rustyline-derive"]
 
 [dependencies]
+# For convenience / compatibilty, you can highlight the whole input buffer, ansi-str helps to split
+ansi-str = { version = "0.8.0", optional = true }
+# ansi_str::Style is immutable so we use anstyle::Style instead
+anstyle = { version = "1.0.8", optional = true }
 bitflags = "2.6"
 cfg-if = "1.0"
 # For file completion
@@ -69,6 +70,8 @@ with-file-history = ["fd-lock"]
 with-sqlite-history = ["rusqlite"]
 with-fuzzy = ["skim"]
 case_insensitive_history_search = ["regex"]
+# For continuation prompt, indentation, scrolling
+split-highlight = []
 
 [[example]]
 name = "custom_key_bindings"
@@ -96,7 +99,15 @@ name = "sqlite_history"
 required-features = ["with-sqlite-history"]
 
 [package.metadata.docs.rs]
-features = ["custom-bindings", "derive", "with-dirs", "with-file-history", "with-fuzzy"]
+features = [
+    "custom-bindings",
+    "derive",
+    "with-dirs",
+    "with-file-history",
+    "with-fuzzy",
+    "split-highlight",
+    "anstyle",
+]
 all-features = false
 no-default-features = true
 default-target = "x86_64-unknown-linux-gnu"

examples/example.rs

@@ -37,10 +37,20 @@ impl Highlighter for MyHelper {
         Owned("\x1b[1m".to_owned() + hint + "\x1b[m")
     }
 
+    #[cfg(any(not(feature = "split-highlight"), feature = "ansi-str"))]
     fn highlight<'l>(&self, line: &'l str, pos: usize) -> Cow<'l, str> {
         self.highlighter.highlight(line, pos)
     }
 
+    #[cfg(all(feature = "split-highlight", not(feature = "ansi-str")))]
+    fn highlight_line<'l>(
+        &self,
+        line: &'l str,
+        pos: usize,
+    ) -> impl Iterator<Item = impl 'l + rustyline::highlight::StyledBlock> {
+        self.highlighter.highlight_line(line, pos)
+    }
+
     fn highlight_char(&self, line: &str, pos: usize, kind: CmdKind) -> bool {
         self.highlighter.highlight_char(line, pos, kind)
     }

examples/read_password.rs

@@ -1,5 +1,3 @@
-use std::borrow::Cow::{self, Borrowed, Owned};
-
 use rustyline::config::Configurer;
 use rustyline::highlight::{CmdKind, Highlighter};
 use rustyline::{ColorMode, Editor, Result};
@@ -11,12 +9,31 @@ struct MaskingHighlighter {
 }
 
 impl Highlighter for MaskingHighlighter {
-    fn highlight<'l>(&self, line: &'l str, _pos: usize) -> Cow<'l, str> {
+    #[cfg(any(not(feature = "split-highlight"), feature = "ansi-str"))]
+    fn highlight<'l>(&self, line: &'l str, _pos: usize) -> std::borrow::Cow<'l, str> {
+        use unicode_width::UnicodeWidthStr;
+        if self.masking {
+            std::borrow::Cow::Owned(" ".repeat(line.width()))
+        } else {
+            std::borrow::Cow::Borrowed(line)
+        }
+    }
+
+    #[cfg(all(feature = "split-highlight", not(feature = "ansi-str")))]
+    fn highlight_line<'l>(
+        &self,
+        line: &'l str,
+        _pos: usize,
+    ) -> impl Iterator<Item = impl 'l + rustyline::highlight::StyledBlock> {
         use unicode_width::UnicodeWidthStr;
         if self.masking {
-            Owned(" ".repeat(line.width()))
+            vec![(
+                rustyline::highlight::AnsiStyle::default(),
+                " ".repeat(line.width()),
+            )]
+            .into_iter()
         } else {
-            Borrowed(line)
+            vec![(rustyline::highlight::AnsiStyle::default(), line.to_owned())].into_iter()
         }
     }
 

rustyline-derive/src/lib.rs

@@ -102,10 +102,20 @@ pub fn highlighter_macro_derive(input: TokenStream) -> TokenStream {
         quote! {
             #[automatically_derived]
             impl #impl_generics ::rustyline::highlight::Highlighter for #name #ty_generics #where_clause {
+                #[cfg(any(not(feature = "split-highlight"), feature = "ansi-str"))]
                 fn highlight<'l>(&self, line: &'l str, pos: usize) -> ::std::borrow::Cow<'l, str> {
                     ::rustyline::highlight::Highlighter::highlight(&self.#field_name_or_index, line, pos)
                 }
 
+                #[cfg(all(feature = "split-highlight", not(feature = "ansi-str")))]
+                fn highlight_line<'l>(
+                    &self,
+                    line: &'l str,
+                    pos: usize,
+                ) -> impl Iterator<Item = impl 'l + ::rustyline::highlight::StyledBlock> {
+                    ::rustyline::highlight::Highlighter::highlight_line(&self.#field_name_or_index, line, pos)
+                }
+
                 fn highlight_prompt<'b, 's: 'b, 'p: 'b>(
                     &'s self,
                     prompt: &'p str,

src/edit.rs

@@ -7,7 +7,7 @@ use unicode_width::UnicodeWidthChar;
 
 use super::{Context, Helper, Result};
 use crate::error::ReadlineError;
-use crate::highlight::{CmdKind, Highlighter};
+use crate::highlight::CmdKind;
 use crate::hint::Hint;
 use crate::history::SearchDirection;
 use crate::keymap::{Anchor, At, CharSearch, Cmd, Movement, RepeatCount, Word};
@@ -68,9 +68,9 @@ impl<'out, 'prompt, H: Helper> State<'out, 'prompt, H> {
         }
     }
 
-    pub fn highlighter(&self) -> Option<&dyn Highlighter> {
+    pub fn highlighter(&self) -> Option<&H> {
         if self.out.colors_enabled() {
-            self.helper.map(|h| h as &dyn Highlighter)
+            self.helper
         } else {
             None
         }
@@ -167,7 +167,7 @@ impl<'out, 'prompt, H: Helper> State<'out, 'prompt, H> {
             Info::Msg(msg) => msg,
         };
         let highlighter = if self.out.colors_enabled() {
-            self.helper.map(|h| h as &dyn Highlighter)
+            self.helper
         } else {
             None
         };

src/error.rs

@@ -125,7 +125,7 @@ impl From<std::string::FromUtf8Error> for ReadlineError {
     }
 }
 
-#[cfg(unix)]
+#[cfg(any(unix, all(feature = "split-highlight", not(feature = "ansi-str"))))]
 impl From<fmt::Error> for ReadlineError {
     fn from(err: fmt::Error) -> Self {
         Self::Io(io::Error::new(io::ErrorKind::Other, err))