mutable Helper in functions

examples/custom_key_bindings.rs

@@ -14,7 +14,7 @@ struct MyHelper(#[rustyline(Hinter)] HistoryHinter);
 
 impl Highlighter for MyHelper {
     fn highlight_prompt<'b, 's: 'b, 'p: 'b>(
-        &'s self,
+        &'s mut self,
         prompt: &'p str,
         default: bool,
     ) -> Cow<'b, str> {
@@ -25,7 +25,7 @@ impl Highlighter for MyHelper {
         }
     }
 
-    fn highlight_hint<'h>(&self, hint: &'h str) -> Cow<'h, str> {
+    fn highlight_hint<'h>(&mut self, hint: &'h str) -> Cow<'h, str> {
         Owned(format!("\x1b[1m{hint}\x1b[m"))
     }
 }

examples/diy_hints.rs

@@ -6,7 +6,7 @@ use rustyline::Context;
 use rustyline::{Completer, Helper, Highlighter, Validator};
 use rustyline::{Editor, Result};
 
-#[derive(Completer, Helper, Validator, Highlighter)]
+#[derive(Completer, Helper, Highlighter, Validator)]
 struct DIYHinter {
     // It's simple example of rustyline, for more efficient, please use ** radix trie **
     hints: HashSet<CommandHint>,
@@ -52,7 +52,7 @@ impl CommandHint {
 impl Hinter for DIYHinter {
     type Hint = CommandHint;
 
-    fn hint(&self, line: &str, pos: usize, _ctx: &Context<'_>) -> Option<CommandHint> {
+    fn hint(&mut self, line: &str, pos: usize, _ctx: &Context<'_>) -> Option<CommandHint> {
         if line.is_empty() || pos < line.len() {
             return None;
         }

examples/example.rs

@@ -8,7 +8,7 @@ use rustyline::validate::MatchingBracketValidator;
 use rustyline::{Cmd, CompletionType, Config, EditMode, Editor, KeyEvent};
 use rustyline::{Completer, Helper, Hinter, Validator};
 
-#[derive(Helper, Completer, Hinter, Validator)]
+#[derive(Completer, Helper, Hinter, Validator)]
 struct MyHelper {
     #[rustyline(Completer)]
     completer: FilenameCompleter,
@@ -22,7 +22,7 @@ struct MyHelper {
 
 impl Highlighter for MyHelper {
     fn highlight_prompt<'b, 's: 'b, 'p: 'b>(
-        &'s self,
+        &'s mut self,
         prompt: &'p str,
         default: bool,
     ) -> Cow<'b, str> {
@@ -33,15 +33,15 @@ impl Highlighter for MyHelper {
         }
     }
 
-    fn highlight_hint<'h>(&self, hint: &'h str) -> Cow<'h, str> {
+    fn highlight_hint<'h>(&mut self, hint: &'h str) -> Cow<'h, str> {
         Owned("\x1b[1m".to_owned() + hint + "\x1b[m")
     }
 
-    fn highlight<'l>(&self, line: &'l str, pos: usize) -> Cow<'l, str> {
+    fn highlight<'l>(&mut self, line: &'l str, pos: usize) -> Cow<'l, str> {
         self.highlighter.highlight(line, pos)
     }
 
-    fn highlight_char(&self, line: &str, pos: usize, forced: bool) -> bool {
+    fn highlight_char(&mut self, line: &str, pos: usize, forced: bool) -> bool {
         self.highlighter.highlight_char(line, pos, forced)
     }
 }

examples/input_validation.rs

@@ -6,7 +6,7 @@ use rustyline::{Editor, Result};
 struct InputValidator {}
 
 impl Validator for InputValidator {
-    fn validate(&self, ctx: &mut ValidationContext) -> Result<ValidationResult> {
+    fn validate(&mut self, ctx: &mut ValidationContext) -> Result<ValidationResult> {
         use ValidationResult::{Incomplete, Invalid, Valid};
         let input = ctx.input();
         let result = if !input.starts_with("SELECT") {

examples/read_password.rs

@@ -11,7 +11,7 @@ struct MaskingHighlighter {
 }
 
 impl Highlighter for MaskingHighlighter {
-    fn highlight<'l>(&self, line: &'l str, _pos: usize) -> Cow<'l, str> {
+    fn highlight<'l>(&mut self, line: &'l str, _pos: usize) -> Cow<'l, str> {
         use unicode_width::UnicodeWidthStr;
         if self.masking {
             Owned(" ".repeat(line.width()))
@@ -20,7 +20,7 @@ impl Highlighter for MaskingHighlighter {
         }
     }
 
-    fn highlight_char(&self, _line: &str, _pos: usize, _forced: bool) -> bool {
+    fn highlight_char(&mut self, _line: &str, _pos: usize, _forced: bool) -> bool {
         self.masking
     }
 }

rustyline-derive/src/lib.rs

@@ -51,16 +51,16 @@ pub fn completer_macro_derive(input: TokenStream) -> TokenStream {
                 type Candidate = <#field_type as ::rustyline::completion::Completer>::Candidate;
 
                 fn complete(
-                    &self,
+                    &mut self,
                     line: &str,
                     pos: usize,
                     ctx: &::rustyline::Context<'_>,
                 ) -> ::rustyline::Result<(usize, ::std::vec::Vec<Self::Candidate>)> {
-                    ::rustyline::completion::Completer::complete(&self.#field_name_or_index, line, pos, ctx)
+                    ::rustyline::completion::Completer::complete(&mut self.#field_name_or_index, line, pos, ctx)
                 }
 
-                fn update(&self, line: &mut ::rustyline::line_buffer::LineBuffer, start: usize, elected: &str, cl: &mut ::rustyline::Changeset) {
-                    ::rustyline::completion::Completer::update(&self.#field_name_or_index, line, start, elected, cl)
+                fn update(&mut self, line: &mut ::rustyline::line_buffer::LineBuffer, start: usize, elected: &str, cl: &mut ::rustyline::Changeset) {
+                    ::rustyline::completion::Completer::update(&mut self.#field_name_or_index, line, start, elected, cl)
                 }
             }
         }
@@ -102,32 +102,32 @@ pub fn highlighter_macro_derive(input: TokenStream) -> TokenStream {
         quote! {
             #[automatically_derived]
             impl #impl_generics ::rustyline::highlight::Highlighter for #name #ty_generics #where_clause {
-                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)
+                fn highlight<'l>(&mut self, line: &'l str, pos: usize) -> ::std::borrow::Cow<'l, str> {
+                    ::rustyline::highlight::Highlighter::highlight(&mut self.#field_name_or_index, line, pos)
                 }
 
                 fn highlight_prompt<'b, 's: 'b, 'p: 'b>(
-                    &'s self,
+                    &'s mut self,
                     prompt: &'p str,
                     default: bool,
                 ) -> ::std::borrow::Cow<'b, str> {
-                    ::rustyline::highlight::Highlighter::highlight_prompt(&self.#field_name_or_index, prompt, default)
+                    ::rustyline::highlight::Highlighter::highlight_prompt(&mut self.#field_name_or_index, prompt, default)
                 }
 
-                fn highlight_hint<'h>(&self, hint: &'h str) -> ::std::borrow::Cow<'h, str> {
-                    ::rustyline::highlight::Highlighter::highlight_hint(&self.#field_name_or_index, hint)
+                fn highlight_hint<'h>(&mut self, hint: &'h str) -> ::std::borrow::Cow<'h, str> {
+                    ::rustyline::highlight::Highlighter::highlight_hint(&mut self.#field_name_or_index, hint)
                 }
 
                 fn highlight_candidate<'c>(
-                    &self,
+                    &mut self,
                     candidate: &'c str,
                     completion: ::rustyline::config::CompletionType,
                 ) -> ::std::borrow::Cow<'c, str> {
-                    ::rustyline::highlight::Highlighter::highlight_candidate(&self.#field_name_or_index, candidate, completion)
+                    ::rustyline::highlight::Highlighter::highlight_candidate(&mut self.#field_name_or_index, candidate, completion)
                 }
 
-                fn highlight_char(&self, line: &str, pos: usize, forced: bool) -> bool {
-                    ::rustyline::highlight::Highlighter::highlight_char(&self.#field_name_or_index, line, pos, forced)
+                fn highlight_char(&mut self, line: &str, pos: usize, forced: bool) -> bool {
+                    ::rustyline::highlight::Highlighter::highlight_char(&mut self.#field_name_or_index, line, pos, forced)
                 }
             }
         }
@@ -156,8 +156,8 @@ pub fn hinter_macro_derive(input: TokenStream) -> TokenStream {
             impl #impl_generics ::rustyline::hint::Hinter for #name #ty_generics #where_clause {
                 type Hint = <#field_type as ::rustyline::hint::Hinter>::Hint;
 
-                fn hint(&self, line: &str, pos: usize, ctx: &::rustyline::Context<'_>) -> ::std::option::Option<Self::Hint> {
-                    ::rustyline::hint::Hinter::hint(&self.#field_name_or_index, line, pos, ctx)
+                fn hint(&mut self, line: &str, pos: usize, ctx: &::rustyline::Context<'_>) -> ::std::option::Option<Self::Hint> {
+                    ::rustyline::hint::Hinter::hint(&mut self.#field_name_or_index, line, pos, ctx)
                 }
             }
         }
@@ -185,14 +185,14 @@ pub fn validator_macro_derive(input: TokenStream) -> TokenStream {
             #[automatically_derived]
             impl #impl_generics ::rustyline::validate::Validator for #name #ty_generics #where_clause {
                 fn validate(
-                    &self,
+                    &mut self,
                     ctx: &mut ::rustyline::validate::ValidationContext,
                 ) -> ::rustyline::Result<::rustyline::validate::ValidationResult> {
-                    ::rustyline::validate::Validator::validate(&self.#field_name_or_index, ctx)
+                    ::rustyline::validate::Validator::validate(&mut self.#field_name_or_index, ctx)
                 }
 
-                fn validate_while_typing(&self) -> bool {
-                    ::rustyline::validate::Validator::validate_while_typing(&self.#field_name_or_index)
+                fn validate_while_typing(&mut self) -> bool {
+                    ::rustyline::validate::Validator::validate_while_typing(&mut self.#field_name_or_index)
                 }
             }
         }

src/completion.rs

@@ -90,7 +90,7 @@ pub trait Completer {
     ///
     /// ("ls /usr/loc", 11) => Ok((3, vec!["/usr/local/"]))
     fn complete(
-        &self, // FIXME should be `&mut self`
+        &mut self,
         line: &str,
         pos: usize,
         ctx: &Context<'_>,
@@ -99,7 +99,7 @@ pub trait Completer {
         Ok((0, Vec::with_capacity(0)))
     }
     /// Updates the edited `line` with the `elected` candidate.
-    fn update(&self, line: &mut LineBuffer, start: usize, elected: &str, cl: &mut Changeset) {
+    fn update(&mut self, line: &mut LineBuffer, start: usize, elected: &str, cl: &mut Changeset) {
         let end = line.pos();
         line.replace(start..end, elected, cl);
     }
@@ -108,38 +108,52 @@ pub trait Completer {
 impl Completer for () {
     type Candidate = String;
 
-    fn update(&self, _line: &mut LineBuffer, _start: usize, _elected: &str, _cl: &mut Changeset) {
+    fn update(
+        &mut self,
+        _line: &mut LineBuffer,
+        _start: usize,
+        _elected: &str,
+        _cl: &mut Changeset,
+    ) {
         unreachable!();
     }
 }
 
-impl<'c, C: ?Sized + Completer> Completer for &'c C {
+impl<'c, C: ?Sized + Completer> Completer for &'c mut C {
     type Candidate = C::Candidate;
 
     fn complete(
-        &self,
+        &mut self,
         line: &str,
         pos: usize,
         ctx: &Context<'_>,
     ) -> Result<(usize, Vec<Self::Candidate>)> {
         (**self).complete(line, pos, ctx)
     }
 
-    fn update(&self, line: &mut LineBuffer, start: usize, elected: &str, cl: &mut Changeset) {
+    fn update(&mut self, line: &mut LineBuffer, start: usize, elected: &str, cl: &mut Changeset) {
         (**self).update(line, start, elected, cl);
     }
 }
-macro_rules! box_completer {
+macro_rules! rc_completer {
     ($($id: ident)*) => {
         $(
             impl<C: ?Sized + Completer> Completer for $id<C> {
                 type Candidate = C::Candidate;
 
-                fn complete(&self, line: &str, pos: usize, ctx: &Context<'_>) -> Result<(usize, Vec<Self::Candidate>)> {
-                    (**self).complete(line, pos, ctx)
+                fn complete(&mut self, line: &str, pos: usize, ctx: &Context<'_>) -> Result<(usize, Vec<Self::Candidate>)> {
+                    if let Some(c) = $id::get_mut(self){
+                        c.complete(line, pos, ctx)
+                    } else {
+                        unreachable!()
+                    }
                 }
-                fn update(&self, line: &mut LineBuffer, start: usize, elected: &str, cl: &mut Changeset) {
-                    (**self).update(line, start, elected, cl)
+                fn update(&mut self, line: &mut LineBuffer, start: usize, elected: &str, cl: &mut Changeset) {
+                    if let Some(c) = $id::get_mut(self){
+                        c.update(line, start, elected, cl)
+                    } else {
+                        unreachable!()
+                    }
                 }
             }
         )*
@@ -149,7 +163,23 @@ macro_rules! box_completer {
 use crate::undo::Changeset;
 use std::rc::Rc;
 use std::sync::Arc;
-box_completer! { Box Rc Arc }
+rc_completer! { Rc Arc }
+
+impl<C: ?Sized + Completer> Completer for Box<C> {
+    type Candidate = C::Candidate;
+
+    fn complete(
+        &mut self,
+        line: &str,
+        pos: usize,
+        ctx: &Context<'_>,
+    ) -> Result<(usize, Vec<Self::Candidate>)> {
+        (**self).complete(line, pos, ctx)
+    }
+    fn update(&mut self, line: &mut LineBuffer, start: usize, elected: &str, cl: &mut Changeset) {
+        (**self).update(line, start, elected, cl)
+    }
+}
 
 /// A `Completer` for file and folder names.
 pub struct FilenameCompleter {
@@ -256,7 +286,12 @@ impl Default for FilenameCompleter {
 impl Completer for FilenameCompleter {
     type Candidate = Pair;
 
-    fn complete(&self, line: &str, pos: usize, _ctx: &Context<'_>) -> Result<(usize, Vec<Pair>)> {
+    fn complete(
+        &mut self,
+        line: &str,
+        pos: usize,
+        _ctx: &Context<'_>,
+    ) -> Result<(usize, Vec<Pair>)> {
         self.complete_path(line, pos)
     }
 }