Clean up error handling

crates/edit/Cargo.toml

@@ -40,7 +40,6 @@ features = [
     "Win32_Security",
     "Win32_Storage_FileSystem",
     "Win32_System_Console",
-    "Win32_System_Diagnostics_Debug",
     "Win32_System_IO",
     "Win32_System_LibraryLoader",
     "Win32_System_Threading",

crates/edit/src/bin/edit/documents.rs

@@ -3,14 +3,15 @@
 
 use std::collections::LinkedList;
 use std::ffi::OsStr;
-use std::fs;
 use std::fs::File;
 use std::path::{Path, PathBuf};
+use std::{fs, io};
 
 use edit::buffer::{RcTextBuffer, TextBuffer};
 use edit::helpers::{CoordType, Point};
-use edit::{apperr, path, sys};
+use edit::{path, sys};
 
+use crate::apperr;
 use crate::state::DisplayablePathBuf;
 
 pub struct Document {
@@ -144,10 +145,10 @@ impl DocumentManager {
         let (path, goto) = Self::parse_filename_goto(path);
         let path = path::normalize(path);
 
-        let mut file = match Self::open_for_reading(&path) {
+        let mut file = match File::open(&path) {
             Ok(file) => Some(file),
-            Err(err) if sys::apperr_is_not_found(err) => None,
-            Err(err) => return Err(err),
+            Err(err) if err.kind() == io::ErrorKind::NotFound => None,
+            Err(err) => return Err(err.into()),
         };
 
         let file_id = if file.is_some() { Some(sys::file_id(file.as_ref(), &path)?) } else { None };

crates/edit/src/bin/edit/draw_editor.rs

@@ -38,7 +38,7 @@ pub fn draw_editor(ctx: &mut Context, state: &mut State) {
 
 fn draw_search(ctx: &mut Context, state: &mut State) {
     if let Err(err) = icu::init() {
-        error_log_add(ctx, state, err);
+        error_log_add(ctx, state, err.into());
         state.wants_search.kind = StateSearchKind::Disabled;
         return;
     }

crates/edit/src/bin/edit/draw_filepicker.rs

@@ -341,7 +341,7 @@ fn draw_dialog_saveas_refresh_files(state: &mut State) {
     }
 
     for entries in &mut dirs_files[1..] {
-        entries.sort_by(|a, b| {
+        entries.sort_unstable_by(|a, b| {
             let a = a.as_bytes();
             let b = b.as_bytes();
 

crates/edit/src/bin/edit/draw_statusbar.rs

@@ -302,7 +302,7 @@ fn encoding_picker_update_list(state: &mut State) {
         }
     }
 
-    matches.sort_by(|a, b| b.0.cmp(&a.0));
+    matches.sort_unstable_by(|a, b| b.0.cmp(&a.0));
     state.encoding_picker_results = Some(Vec::from_iter(matches.iter().map(|(_, enc)| *enc)));
 }
 

crates/edit/src/bin/edit/localization.rs

@@ -1,8 +1,8 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
-use edit::helpers::AsciiStringHelpers;
 use edit::sys;
+use stdext::AsciiStringHelpers as _;
 use stdext::arena::scratch_arena;
 
 include!(concat!(env!("OUT_DIR"), "/i18n_edit.rs"));

crates/edit/src/bin/edit/main.rs

@@ -3,6 +3,7 @@
 
 #![feature(allocator_api, linked_list_cursors, string_from_utf8_lossy_owned)]
 
+mod apperr;
 mod documents;
 mod draw_editor;
 mod draw_filepicker;
@@ -26,7 +27,7 @@ use edit::input::{self, kbmod, vk};
 use edit::oklab::StraightRgba;
 use edit::tui::*;
 use edit::vt::{self, Token};
-use edit::{apperr, base64, path, sys, unicode};
+use edit::{base64, path, sys, unicode};
 use localization::*;
 use state::*;
 use stdext::arena::{self, Arena, ArenaString, scratch_arena};
@@ -37,6 +38,9 @@ const SCRATCH_ARENA_CAPACITY: usize = 128 * MEBI;
 #[cfg(target_pointer_width = "64")]
 const SCRATCH_ARENA_CAPACITY: usize = 512 * MEBI;
 
+// NOTE: Before our main() gets called, Rust initializes its stdlib. This pulls in the entire
+// std::io::{stdin, stdout, stderr} machinery, and probably some more, which amounts to about 20KB.
+// It can technically be avoided nowadays with `#![no_main]`. Maybe a fun project for later? :)
 fn main() -> process::ExitCode {
     if cfg!(debug_assertions) {
         let hook = std::panic::take_hook();

crates/edit/src/bin/edit/state.rs

@@ -10,8 +10,9 @@ use edit::framebuffer::IndexedColor;
 use edit::helpers::*;
 use edit::oklab::StraightRgba;
 use edit::tui::*;
-use edit::{apperr, buffer, icu, sys};
+use edit::{buffer, icu};
 
+use crate::apperr;
 use crate::documents::DocumentManager;
 use crate::localization::*;
 
@@ -27,10 +28,9 @@ impl From<apperr::Error> for FormatApperr {
 impl std::fmt::Display for FormatApperr {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self.0 {
-            apperr::APP_ICU_MISSING => f.write_str(loc(LocId::ErrorIcuMissing)),
-            apperr::Error::App(code) => write!(f, "Unknown app error code: {code}"),
-            apperr::Error::Icu(code) => icu::apperr_format(f, code),
-            apperr::Error::Sys(code) => sys::apperr_format(f, code),
+            apperr::Error::Icu(icu::ICU_MISSING_ERROR) => f.write_str(loc(LocId::ErrorIcuMissing)),
+            apperr::Error::Icu(ref err) => err.fmt(f),
+            apperr::Error::Io(ref err) => err.fmt(f),
         }
     }
 }

crates/edit/src/buffer/gap_buffer.rs

@@ -3,11 +3,11 @@
 
 use std::ops::Range;
 use std::ptr::{self, NonNull};
-use std::slice;
+use std::{io, slice};
 
 use stdext::sys::{virtual_commit, virtual_release, virtual_reserve};
+use stdext::{ReplaceRange as _, slice_copy_safe};
 
-use crate::apperr;
 use crate::document::{ReadableDocument, WriteableDocument};
 use crate::helpers::*;
 
@@ -64,7 +64,7 @@ pub struct GapBuffer {
 }
 
 impl GapBuffer {
-    pub fn new(small: bool) -> apperr::Result<Self> {
+    pub fn new(small: bool) -> io::Result<Self> {
         let reserve;
         let buffer;
         let text;