From c9d530504fc28fbc16540c97f292f60c6179e96a Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Thu, 23 Apr 2026 18:08:51 +0300
Subject: [PATCH] readline: fix The read_char () of the readline module does
 not work in Windows OS. (fixes #24686)

---
 vlib/readline/readline.v                      |  2 +
 vlib/readline/readline_windows.c.v            | 72 ++++++++++++++++++-
 .../tests/projects_that_should_compile_test.v | 21 ++++++
 3 files changed, 94 insertions(+), 1 deletion(-)

diff --git a/vlib/readline/readline.v b/vlib/readline/readline.v
index a3ee4932e..887c542a6 100644
--- a/vlib/readline/readline.v
+++ b/vlib/readline/readline.v
@@ -36,4 +36,6 @@ pub mut:
 	last_completion_offset int
 	completion_list        []string
 	completion_callback    fn (string) []string = unsafe { nil }
+mut:
+	orig_stdin_mode u32 // Windows
 }
diff --git a/vlib/readline/readline_windows.c.v b/vlib/readline/readline_windows.c.v
index f02d078af..fc5ae200e 100644
--- a/vlib/readline/readline_windows.c.v
+++ b/vlib/readline/readline_windows.c.v
@@ -2,7 +2,8 @@
 // Use of this source code is governed by an MIT license
 // that can be found in the LICENSE file.
 //
-// TODO: Windows version needs to be implemented.
+// Windows currently supports basic line reading and raw-character input.
+// The richer line-editing functionality is still implemented only on nix.
 // Will serve as more advanced input method
 // based on the work of https://github.com/AmokHuginnsson/replxx
 //
@@ -10,10 +11,79 @@ module readline
 
 import os
 
+#include <conio.h>
+#include <windows.h>
+
 // needed for parity with readline_default.c.v
 struct Termios {
 }
 
+fn C._getwch() i32
+
+fn (mut r Readline) set_raw_mode(keep_processed_input bool) {
+	if os.is_atty(0) <= 0 || os.getenv('TERM') == 'dumb' {
+		r.is_tty = false
+		r.is_raw = false
+		return
+	}
+	stdin_handle := C.GetStdHandle(C.STD_INPUT_HANDLE)
+	if stdin_handle == C.INVALID_HANDLE_VALUE || !C.GetConsoleMode(stdin_handle, &r.orig_stdin_mode) {
+		r.is_tty = false
+		r.is_raw = false
+		return
+	}
+	mut raw_mode := r.orig_stdin_mode & (~u32(C.ENABLE_LINE_INPUT | C.ENABLE_ECHO_INPUT))
+	if !keep_processed_input {
+		raw_mode &= ~u32(C.ENABLE_PROCESSED_INPUT)
+	}
+	if !C.SetConsoleMode(stdin_handle, raw_mode) {
+		r.is_tty = false
+		r.is_raw = false
+		return
+	}
+	r.is_tty = true
+	r.is_raw = true
+}
+
+// enable_raw_mode enables the raw mode of the terminal.
+// In raw mode all key presses are directly sent to the program and no interpretation is done.
+pub fn (mut r Readline) enable_raw_mode() {
+	r.set_raw_mode(false)
+}
+
+// enable_raw_mode_nosig enables the raw mode of the terminal while keeping console signal processing enabled.
+pub fn (mut r Readline) enable_raw_mode_nosig() {
+	r.set_raw_mode(true)
+}
+
+// disable_raw_mode disables the raw mode of the terminal.
+pub fn (mut r Readline) disable_raw_mode() {
+	if !r.is_raw {
+		return
+	}
+	stdin_handle := C.GetStdHandle(C.STD_INPUT_HANDLE)
+	if stdin_handle != C.INVALID_HANDLE_VALUE {
+		C.SetConsoleMode(stdin_handle, r.orig_stdin_mode)
+	}
+	r.is_raw = false
+}
+
+// read_char reads a single character.
+pub fn (r Readline) read_char() !int {
+	ch := int(C._getwch())
+	if ch < 0 {
+		return error('failed to read character')
+	}
+	if ch !in [0, 0xe0] {
+		return ch
+	}
+	extended := int(C._getwch())
+	if extended < 0 {
+		return error('failed to read character')
+	}
+	return int((u32(ch) << 16) | u32(extended))
+}
+
 // Only use standard os.get_line
 // Need implementation for readline capabilities
 //
diff --git a/vlib/v/tests/projects_that_should_compile_test.v b/vlib/v/tests/projects_that_should_compile_test.v
index ab07bcbfd..d5f7137ff 100644
--- a/vlib/v/tests/projects_that_should_compile_test.v
+++ b/vlib/v/tests/projects_that_should_compile_test.v
@@ -332,4 +332,25 @@ fn test_usecache_build_module_sumtype_uses_canonical_type_id_helper() {
 	generated_c := os.read_file(generated_c_path)!
 	assert generated_c.contains('payload__Foo_to_sumtype_payload__Value(payload__Foo* x, bool is_mut)')
 	assert generated_c.contains('._typ = _v_type_idx_payload__Foo()')
+fn test_readline_raw_mode_methods_should_check_for_windows() {
+	source_path := os.join_path(os.vtmp_dir(), 'readline_raw_mode_issue_24686_${os.getpid()}.v')
+	source := [
+		'module main',
+		'',
+		'import readline',
+		'',
+		'fn main() {',
+		'\tmut r := readline.Readline{}',
+		'\tr.enable_raw_mode()',
+		'\tr.disable_raw_mode()',
+		'\tr.enable_raw_mode_nosig()',
+		'\tprintln(r.read_char()!)',
+		'\tr.disable_raw_mode()',
+		'}',
+	].join_lines()
+	write_file(source_path, source)
+	defer {
+		os.rm(source_path) or {}
+	}
+	_ = vrun_ok('-os windows -check', source_path)
 }
-- 
2.39.5