vfmt: change all '$expr' to '${expr}' (#16428)

vlib/os/dir_expansions_test.v

@@ -16,7 +16,7 @@ fn test_tmpdir() {
 fn test_ensure_folder_is_writable() {
 	tmp := os.temp_dir()
 	os.ensure_folder_is_writable(tmp) or {
-		eprintln('err: $err')
+		eprintln('err: ${err}')
 		assert false
 	}
 }
@@ -35,7 +35,7 @@ fn test_expand_tilde_to_home() {
 fn test_config_dir() {
 	cdir := os.config_dir()!
 	assert cdir.len > 0
-	adir := '$cdir/test-v-config'
+	adir := '${cdir}/test-v-config'
 	os.mkdir_all(adir)!
 	os.rmdir(adir)!
 	assert os.is_dir(cdir)

vlib/os/environment.c.v

@@ -45,7 +45,7 @@ pub fn getenv_opt(key string) ?string {
 // os.setenv sets the value of an environment variable with `name` to `value`.
 pub fn setenv(name string, value string, overwrite bool) int {
 	$if windows {
-		format := '$name=$value'
+		format := '${name}=${value}'
 		if overwrite {
 			unsafe {
 				return C._putenv(&char(format.str))
@@ -68,7 +68,7 @@ pub fn setenv(name string, value string, overwrite bool) int {
 // os.unsetenv clears an environment variable with `name`.
 pub fn unsetenv(name string) int {
 	$if windows {
-		format := '$name='
+		format := '${name}='
 		return C._putenv(&char(format.str))
 	} $else {
 		return C.unsetenv(&char(name.str))

vlib/os/environment_test.v

@@ -43,12 +43,12 @@ fn test_environ() {
 
 fn test_setenv_var_not_exists() {
 	key := time.new_time(time.now()).unix
-	os.setenv('foo$key', 'bar', false)
-	assert os.getenv('foo$key') == 'bar'
+	os.setenv('foo${key}', 'bar', false)
+	assert os.getenv('foo${key}') == 'bar'
 }
 
 fn test_getenv_empty_var() {
 	key := time.new_time(time.now()).unix
-	os.setenv('empty$key', '""', false)
-	assert os.getenv('empty$key') == '""'
+	os.setenv('empty${key}', '""', false)
+	assert os.getenv('empty${key}') == '""'
 }

vlib/os/file.c.v

@@ -108,7 +108,7 @@ pub fn open_file(path string, mode string, options ...int) !File {
 	fdopen_mode := mode.replace('b', '')
 	cfile := C.fdopen(fd, &char(fdopen_mode.str))
 	if isnil(cfile) {
-		return error('Failed to open or create file "$path"')
+		return error('Failed to open or create file "${path}"')
 	}
 	if seek_to_end {
 		// ensure appending will work, even on bsd/macos systems:
@@ -227,7 +227,7 @@ pub fn (mut f File) reopen(path string, mode string) ! {
 		cfile = C.freopen(&char(p.str), &char(mode.str), f.cfile)
 	}
 	if isnil(cfile) {
-		return error('Failed to reopen file "$path"')
+		return error('Failed to reopen file "${path}"')
 	}
 	f.cfile = cfile
 }

vlib/os/filelock/lib_nix.c.v

@@ -23,7 +23,7 @@ pub fn (mut l FileLock) acquire() ! {
 	}
 	fd := open_lockfile(l.name)
 	if fd == -1 {
-		return error_with_code('cannot create lock file $l.name', -1)
+		return error_with_code('cannot create lock file ${l.name}', -1)
 	}
 	if C.flock(fd, C.LOCK_EX) == -1 {
 		C.close(fd)
@@ -66,7 +66,7 @@ pub fn (mut l FileLock) try_acquire() bool {
 	if l.fd != -1 {
 		return true
 	}
-	fd := open_lockfile('$l.name')
+	fd := open_lockfile('${l.name}')
 	if fd != -1 {
 		err := C.flock(fd, C.LOCK_EX | C.LOCK_NB)
 		if err == -1 {

vlib/os/filelock/lib_windows.c.v

@@ -21,7 +21,7 @@ pub fn (mut l FileLock) acquire() ! {
 	}
 	fd := open(l.name)
 	if fd == -1 {
-		return error_with_code('cannot create lock file $l.name', -1)
+		return error_with_code('cannot create lock file ${l.name}', -1)
 	}
 	l.fd = fd
 }

vlib/os/filepath_test.v

@@ -154,9 +154,9 @@ fn test_existing_path() {
 		assert existing_path('.') or { '' } == '.'
 		assert existing_path(wd) or { '' } == wd
 		assert existing_path('\\') or { '' } == '\\'
-		assert existing_path('$wd\\.\\\\does/not/exist\\.\\') or { '' } == '$wd\\.\\\\'
-		assert existing_path('$wd\\\\/\\.\\.\\/.') or { '' } == '$wd\\\\/\\.\\.\\/.'
-		assert existing_path('$wd\\././/\\/oh') or { '' } == '$wd\\././/\\/'
+		assert existing_path('${wd}\\.\\\\does/not/exist\\.\\') or { '' } == '${wd}\\.\\\\'
+		assert existing_path('${wd}\\\\/\\.\\.\\/.') or { '' } == '${wd}\\\\/\\.\\.\\/.'
+		assert existing_path('${wd}\\././/\\/oh') or { '' } == '${wd}\\././/\\/'
 		return
 	}
 	assert existing_path('') or { '' } == ''
@@ -164,9 +164,9 @@ fn test_existing_path() {
 	assert existing_path('.') or { '' } == '.'
 	assert existing_path(wd) or { '' } == wd
 	assert existing_path('/') or { '' } == '/'
-	assert existing_path('$wd/does/.///not/exist///.//') or { '' } == '$wd/'
-	assert existing_path('$wd//././/.//') or { '' } == '$wd//././/.//'
-	assert existing_path('$wd//././/.//oh') or { '' } == '$wd//././/.//'
+	assert existing_path('${wd}/does/.///not/exist///.//') or { '' } == '${wd}/'
+	assert existing_path('${wd}//././/.//') or { '' } == '${wd}//././/.//'
+	assert existing_path('${wd}//././/.//oh') or { '' } == '${wd}//././/.//'
 }
 
 fn test_windows_volume() {

vlib/os/find_abs_path_of_executable_test.v

@@ -41,7 +41,7 @@ fn test_find_abs_path_of_executable() {
 	os.setenv('PATH', original_path, true)
 	os.chdir(os.home_dir())! // change to a *completely* different folder, to avoid the original PATH containing `.`
 	if x := os.find_abs_path_of_executable('myclang') {
-		eprintln('> find_abs_path_of_executable should have failed, but instead it found: $x')
+		eprintln('> find_abs_path_of_executable should have failed, but instead it found: ${x}')
 		assert false
 	}
 }

vlib/os/font/font.v

@@ -36,7 +36,7 @@ pub fn default() string {
 			'/Library/Fonts/Arial.ttf']
 		for font in fonts {
 			if os.is_file(font) {
-				debug_font_println('Using font "$font"')
+				debug_font_println('Using font "${font}"')
 				return font
 			}
 		}
@@ -58,7 +58,7 @@ pub fn default() string {
 							for location in font_locations {
 								candidate_path := os.join_path(location, candidate_font)
 								if os.is_file(candidate_path) && os.is_readable(candidate_path) {
-									debug_font_println('Using font "$candidate_path"')
+									debug_font_println('Using font "${candidate_path}"')
 									return candidate_path
 								}
 							}
@@ -73,7 +73,7 @@ pub fn default() string {
 		lines := fm.output.split('\n')
 		for l in lines {
 			if !l.contains('.ttc') {
-				debug_font_println('Using font "$l"')
+				debug_font_println('Using font "${l}"')
 				return l
 			}
 		}

vlib/os/inode_test.v

@@ -8,7 +8,7 @@ const (
 )
 
 fn testsuite_begin() {
-	eprintln('testsuite_begin, tfolder = $tfolder')
+	eprintln('testsuite_begin, tfolder = ${tfolder}')
 	os.rmdir_all(tfolder) or {}
 	assert !os.is_dir(tfolder)
 	os.mkdir_all(tfolder) or { panic(err) }

vlib/os/notify/notify_test.v

@@ -8,7 +8,7 @@ fn make_pipe() !(int, int) {
 	$if linux {
 		pipefd := [2]int{}
 		if C.pipe(&pipefd[0]) != 0 {
-			return error('error $C.errno: ' + os.posix_get_error_msg(C.errno))
+			return error('error ${C.errno}: ' + os.posix_get_error_msg(C.errno))
 		}
 		return pipefd[0], pipefd[1]
 	}

vlib/os/open_uri_default.c.v

@@ -23,8 +23,8 @@ pub fn open_uri(uri string) ! {
 	if vopen_uri_cmd == '' {
 		return error('unsupported platform')
 	}
-	result := execute('$vopen_uri_cmd "$uri"')
+	result := execute('${vopen_uri_cmd} "${uri}"')
 	if result.exit_code != 0 {
-		return error('unable to open url: $result.output')
+		return error('unable to open url: ${result.output}')
 	}
 }

vlib/os/open_uri_windows.c.v

@@ -7,9 +7,9 @@ type ShellExecuteWin = fn (voidptr, &u16, &u16, &u16, &u16, int)
 pub fn open_uri(uri string) ! {
 	mut vopen_uri_cmd := getenv('VOPEN_URI_CMD')
 	if vopen_uri_cmd != '' {
-		result := execute('$vopen_uri_cmd "$uri"')
+		result := execute('${vopen_uri_cmd} "${uri}"')
 		if result.exit_code != 0 {
-			return error('unable to open url: $result.output')
+			return error('unable to open url: ${result.output}')
 		}
 		return
 	}

vlib/os/os.c.v

@@ -71,7 +71,7 @@ fn find_cfile_size(fp &C.FILE) !int {
 	len := int(raw_fsize)
 	// For files > 2GB, C.ftell can return values that, when cast to `int`, can result in values below 0.
 	if i64(len) < raw_fsize {
-		return error('int($raw_fsize) cast results in $len')
+		return error('int(${raw_fsize}) cast results in ${len}')
 	}
 	C.rewind(fp)
 	return len
@@ -222,12 +222,12 @@ pub fn mv(src string, dst string) ! {
 		w_dst := rdst.replace('/', '\\')
 		ret := C._wrename(w_src.to_wide(), w_dst.to_wide())
 		if ret != 0 {
-			return error_with_code('failed to rename $src to $dst', int(ret))
+			return error_with_code('failed to rename ${src} to ${dst}', int(ret))
 		}
 	} $else {
 		ret := C.rename(&char(src.str), &char(rdst.str))
 		if ret != 0 {
-			return error_with_code('failed to rename $src to $dst', ret)
+			return error_with_code('failed to rename ${src} to ${dst}', ret)
 		}
 	}
 }
@@ -239,17 +239,17 @@ pub fn cp(src string, dst string) ! {
 		w_dst := dst.replace('/', '\\')
 		if C.CopyFile(w_src.to_wide(), w_dst.to_wide(), false) == 0 {
 			result := C.GetLastError()
-			return error_with_code('failed to copy $src to $dst', int(result))
+			return error_with_code('failed to copy ${src} to ${dst}', int(result))
 		}
 	} $else {
 		fp_from := C.open(&char(src.str), C.O_RDONLY, 0)
 		if fp_from < 0 { // Check if file opened
-			return error_with_code('cp: failed to open $src', int(fp_from))
+			return error_with_code('cp: failed to open ${src}', int(fp_from))
 		}
 		fp_to := C.open(&char(dst.str), C.O_WRONLY | C.O_CREAT | C.O_TRUNC, C.S_IWUSR | C.S_IRUSR)
 		if fp_to < 0 { // Check if file opened (permissions problems ...)
 			C.close(fp_from)
-			return error_with_code('cp (permission): failed to write to $dst (fp_to: $fp_to)',
+			return error_with_code('cp (permission): failed to write to ${dst} (fp_to: ${fp_to})',
 				int(fp_to))
 		}
 		// TODO use defer{} to close files in case of error or return.
@@ -264,7 +264,7 @@ pub fn cp(src string, dst string) ! {
 			if C.write(fp_to, &buf[0], count) < 0 {
 				C.close(fp_to)
 				C.close(fp_from)
-				return error_with_code('cp: failed to write to $dst', int(-1))
+				return error_with_code('cp: failed to write to ${dst}', int(-1))
 			}
 		}
 		from_attr := C.stat{}
@@ -274,7 +274,7 @@ pub fn cp(src string, dst string) ! {
 		if C.chmod(&char(dst.str), from_attr.st_mode) < 0 {
 			C.close(fp_to)
 			C.close(fp_from)
-			return error_with_code('failed to set permissions for $dst', int(-1))
+			return error_with_code('failed to set permissions for ${dst}', int(-1))
 		}
 		C.close(fp_to)
 		C.close(fp_from)
@@ -295,7 +295,7 @@ pub fn vfopen(path string, mode string) !&C.FILE {
 		fp = C.fopen(&char(path.str), &char(mode.str))
 	}
 	if isnil(fp) {
-		return error('failed to open file "$path"')
+		return error('failed to open file "${path}"')
 	} else {
 		return fp
 	}
@@ -373,7 +373,7 @@ pub fn system(cmd string) int {
 	mut ret := 0
 	$if windows {
 		// overcome bug in system & _wsystem (cmd) when first char is quote `"`
-		wcmd := if cmd.len > 1 && cmd[0] == `"` && cmd[1] != `"` { '"$cmd"' } else { cmd }
+		wcmd := if cmd.len > 1 && cmd[0] == `"` && cmd[1] != `"` { '"${cmd}"' } else { cmd }
 		unsafe {
 			ret = C._wsystem(wcmd.to_wide())
 		}
@@ -487,7 +487,7 @@ pub fn rm(path string) ! {
 		rc = C.remove(&char(path.str))
 	}
 	if rc == -1 {
-		return error('Failed to remove "$path": ' + posix_get_error_msg(C.errno))
+		return error('Failed to remove "${path}": ' + posix_get_error_msg(C.errno))
 	}
 	// C.unlink(path.cstr())
 }
@@ -498,7 +498,7 @@ pub fn rmdir(path string) ! {
 		rc := C.RemoveDirectory(path.to_wide())
 		if !rc {
 			// https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-removedirectorya - 0 == false, is failure
-			return error('Failed to remove "$path": ' + posix_get_error_msg(C.errno))
+			return error('Failed to remove "${path}": ' + posix_get_error_msg(C.errno))
 		}
 	} $else {
 		rc := C.rmdir(&char(path.str))
@@ -512,7 +512,7 @@ pub fn rmdir(path string) ! {
 fn print_c_errno() {
 	e := C.errno
 	se := unsafe { tos_clone(&u8(C.strerror(e))) }
-	println('errno=$e err=$se')
+	println('errno=${e} err=${se}')
 }
 
 // get_raw_line returns a one-line string from stdin along with '\n' if there is any.
@@ -612,7 +612,7 @@ pub fn read_file_array<T>(path string) []T {
 	// On some systems C.ftell can return values in the 64-bit range
 	// that, when cast to `int`, can result in values below 0.
 	if i64(allocate) < fsize {
-		panic('$fsize cast to int results in ${int(fsize)})')
+		panic('${fsize} cast to int results in ${int(fsize)})')
 	}
 	buf := unsafe {
 		malloc_noscan(allocate)
@@ -672,7 +672,7 @@ pub fn executable() string {
 		pid := C.getpid()
 		ret := proc_pidpath(pid, &result[0], max_path_len)
 		if ret <= 0 {
-			eprintln('os.executable() failed at calling proc_pidpath with pid: $pid . proc_pidpath returned $ret ')
+			eprintln('os.executable() failed at calling proc_pidpath with pid: ${pid} . proc_pidpath returned ${ret} ')
 			return executable_fallback()
 		}
 		res := unsafe { tos_clone(&result[0]) }
@@ -985,7 +985,7 @@ pub fn open_append(path string) !File {
 		}
 	}
 	if isnil(file.cfile) {
-		return error('failed to create(append) file "$path"')
+		return error('failed to create(append) file "${path}"')
 	}
 	file.is_opened = true
 	return file

vlib/os/os.v

@@ -396,7 +396,7 @@ pub fn user_names() ![]string {
 	$if windows {
 		result := execute('wmic useraccount get name')
 		if result.exit_code != 0 {
-			return error('Failed to get user names. Exited with code $result.exit_code: $result.output')
+			return error('Failed to get user names. Exited with code ${result.exit_code}: ${result.output}')
 		}
 		mut users := result.output.split_into_lines()
 		// windows command prints an empty line at the end of output
@@ -662,7 +662,7 @@ pub fn mkdir_all(opath string, params MkdirParams) ! {
 		if exists(p) && is_dir(p) {
 			continue
 		}
-		mkdir(p, params) or { return error('folder: $p, error: $err') }
+		mkdir(p, params) or { return error('folder: ${p}, error: ${err}') }
 	}
 }
 
@@ -727,7 +727,7 @@ pub fn vtmp_dir() string {
 		return vtmp
 	}
 	uid := getuid()
-	vtmp = join_path_single(temp_dir(), 'v_$uid')
+	vtmp = join_path_single(temp_dir(), 'v_${uid}')
 	if !exists(vtmp) || !is_dir(vtmp) {
 		// create a new directory, that is private to the user:
 		mkdir_all(vtmp, mode: 0o700) or { panic(err) }
@@ -817,8 +817,8 @@ pub mut:
 pub fn execute_or_panic(cmd string) Result {
 	res := execute(cmd)
 	if res.exit_code != 0 {
-		eprintln('failed    cmd: $cmd')
-		eprintln('failed   code: $res.exit_code')
+		eprintln('failed    cmd: ${cmd}')
+		eprintln('failed   code: ${res.exit_code}')
 		panic(res.output)
 	}
 	return res
@@ -827,8 +827,8 @@ pub fn execute_or_panic(cmd string) Result {
 pub fn execute_or_exit(cmd string) Result {
 	res := execute(cmd)
 	if res.exit_code != 0 {
-		eprintln('failed    cmd: $cmd')
-		eprintln('failed   code: $res.exit_code')
+		eprintln('failed    cmd: ${cmd}')
+		eprintln('failed   code: ${res.exit_code}')
 		eprintln(res.output)
 		exit(1)
 	}
@@ -838,9 +838,13 @@ pub fn execute_or_exit(cmd string) Result {
 // quoted path - return a quoted version of the path, depending on the platform.
 pub fn quoted_path(path string) string {
 	$if windows {
-		return if path.ends_with(path_separator) { '"${path + path_separator}"' } else { '"$path"' }
+		return if path.ends_with(path_separator) {
+			'"${path + path_separator}"'
+		} else {
+			'"${path}"'
+		}
 	} $else {
-		return "'$path'"
+		return "'${path}'"
 	}
 }
 

vlib/os/os_android_outside_termux.c.v

@@ -40,7 +40,7 @@ fn C.AAssetManager_open(&C.AAssetManager, &char, int) &C.AAsset
 pub fn (am &AssetManager) open(filename string, mode AssetMode) !&Asset {
 	asset := C.AAssetManager_open(am, filename.str, int(mode))
 	if isnil(asset) {
-		return error('file `$filename` not found')
+		return error('file `${filename}` not found')
 	}
 	return asset
 }

vlib/os/os_js.js.v

@@ -57,7 +57,7 @@ pub fn exists(path string) bool {
 
 pub fn ls(path string) ![]string {
 	if !is_dir(path) {
-		return error('ls(): cannot open dir $dir')
+		return error('ls(): cannot open dir ${dir}')
 	}
 
 	result := []string{}

vlib/os/os_nix.c.v

@@ -87,8 +87,8 @@ fn glob_match(dir string, pattern string, next_pattern string, mut matches []str
 		mode = GlobMatch.any
 		if next_pattern != pattern && next_pattern != '' {
 			for file in files {
-				if is_dir('$dir/$file') {
-					subdirs << '$dir/$file'
+				if is_dir('${dir}/${file}') {
+					subdirs << '${dir}/${file}'
 				}
 			}
 			return subdirs
@@ -115,7 +115,7 @@ fn glob_match(dir string, pattern string, next_pattern string, mut matches []str
 			pathwalk := file.split(os.path_separator)
 			pathwalk[pathwalk.len - 1]
 		} else {
-			fpath = if dir == '.' { file } else { '$dir/$file' }
+			fpath = if dir == '.' { file } else { '${dir}/${file}' }
 			file
 		}
 		if f in ['.', '..'] || f == '' {
@@ -146,7 +146,7 @@ fn glob_match(dir string, pattern string, next_pattern string, mut matches []str
 			if is_dir(fpath) {
 				subdirs << fpath
 				if next_pattern == pattern && next_pattern != '' {
-					matches << '$fpath$os.path_separator'
+					matches << '${fpath}${os.path_separator}'
 				}
 			} else {
 				matches << fpath
@@ -166,14 +166,14 @@ fn native_glob_pattern(pattern string, mut matches []string) ! {
 		if step == '' {
 			continue
 		}
-		if is_dir('$cwd$os.path_separator$step') {
+		if is_dir('${cwd}${os.path_separator}${step}') {
 			dd := if cwd == '/' {
 				step
 			} else {
 				if cwd == '.' || cwd == '' {
 					step
 				} else {
-					if step == '.' || step == '/' { cwd } else { '$cwd/$step' }
+					if step == '.' || step == '/' { cwd } else { '${cwd}/${step}' }
 				}
 			}
 			if i + 1 != steps.len {
@@ -190,7 +190,7 @@ fn native_glob_pattern(pattern string, mut matches []string) ! {
 				if cwd == '.' || cwd == '' {
 					sd
 				} else {
-					if sd == '.' || sd == '/' { cwd } else { '$cwd/$sd' }
+					if sd == '.' || sd == '/' { cwd } else { '${cwd}/${sd}' }
 				}
 			}
 			subs << glob_match(d.replace('//', '/'), step, step2, mut matches)
@@ -259,7 +259,7 @@ pub fn ls(path string) ![]string {
 	mut res := []string{cap: 50}
 	dir := unsafe { C.opendir(&char(path.str)) }
 	if isnil(dir) {
-		return error('ls() couldnt open dir "$path"')
+		return error('ls() couldnt open dir "${path}"')
 	}
 	mut ent := &C.dirent(0)
 	// mut ent := &C.dirent{!}
@@ -299,7 +299,7 @@ pub fn execute(cmd string) Result {
 	// if cmd.contains(';') || cmd.contains('&&') || cmd.contains('||') || cmd.contains('\n') {
 	// return Result{ exit_code: -1, output: ';, &&, || and \\n are not allowed in shell commands' }
 	// }
-	pcmd := if cmd.contains('2>') { cmd.clone() } else { '$cmd 2>&1' }
+	pcmd := if cmd.contains('2>') { cmd.clone() } else { '${cmd} 2>&1' }
 	defer {
 		unsafe { pcmd.free() }
 	}
@@ -307,7 +307,7 @@ pub fn execute(cmd string) Result {
 	if isnil(f) {
 		return Result{
 			exit_code: -1
-			output: 'exec("$cmd") failed'
+			output: 'exec("${cmd}") failed'
 		}
 	}
 	fd := fileno(f)
@@ -351,7 +351,7 @@ pub fn (mut c Command) start() ! {
 	}
 	c.f = vpopen(pcmd)
 	if isnil(c.f) {
-		return error('exec("$c.path") failed')
+		return error('exec("${c.path}") failed')
 	}
 }
 
@@ -437,10 +437,10 @@ fn C.mkstemp(stemplate &u8) int
 [manualfree]
 pub fn ensure_folder_is_writable(folder string) ! {
 	if !exists(folder) {
-		return error_with_code('`$folder` does not exist', 1)
+		return error_with_code('`${folder}` does not exist', 1)
 	}
 	if !is_dir(folder) {
-		return error_with_code('`$folder` is not a folder', 2)
+		return error_with_code('`${folder}` is not a folder', 2)
 	}
 	tmp_perm_check := join_path_single(folder, 'XXXXXX')
 	defer {
@@ -449,7 +449,7 @@ pub fn ensure_folder_is_writable(folder string) ! {
 	unsafe {
 		x := C.mkstemp(&char(tmp_perm_check.str))
 		if -1 == x {
-			return error_with_code('folder `$folder` is not writable', 3)
+			return error_with_code('folder `${folder}` is not writable', 3)
 		}
 		C.close(x)
 	}

vlib/os/os_test.v

@@ -13,7 +13,7 @@ const (
 const args_at_start = os.args.clone()
 
 fn testsuite_begin() {
-	eprintln('testsuite_begin, tfolder = $tfolder')
+	eprintln('testsuite_begin, tfolder = ${tfolder}')
 	os.rmdir_all(tfolder) or {}
 	assert !os.is_dir(tfolder)
 	os.mkdir_all(tfolder) or { panic(err) }
@@ -42,7 +42,7 @@ fn test_open_file() {
 	file.write_string(hello) or { panic(err) }
 	file.close()
 	assert u64(hello.len) == os.file_size(filename)
-	read_hello := os.read_file(filename) or { panic('error reading file $filename') }
+	read_hello := os.read_file(filename) or { panic('error reading file ${filename}') }
 	assert hello == read_hello
 	os.rm(filename) or { panic(err) }
 }
@@ -82,7 +82,7 @@ fn test_open_file_binary() {
 	unsafe { file.write_ptr(bytes.data, bytes.len) }
 	file.close()
 	assert u64(hello.len) == os.file_size(filename)
-	read_hello := os.read_bytes(filename) or { panic('error reading file $filename') }
+	read_hello := os.read_bytes(filename) or { panic('error reading file ${filename}') }
 	assert bytes == read_hello
 	os.rm(filename) or { panic(err) }
 }
@@ -162,7 +162,7 @@ fn test_write_and_read_string_to_file() {
 	hello := 'hello world!'
 	os.write_file(filename, hello) or { panic(err) }
 	assert u64(hello.len) == os.file_size(filename)
-	read_hello := os.read_file(filename) or { panic('error reading file $filename') }
+	read_hello := os.read_file(filename) or { panic('error reading file ${filename}') }
 	assert hello == read_hello
 	os.rm(filename) or { panic(err) }
 }
@@ -173,7 +173,7 @@ fn test_write_and_read_bytes() {
 	file_name := './byte_reader_writer.tst'
 	payload := [u8(`I`), `D`, `D`, `Q`, `D`]
 	mut file_write := os.create(os.real_path(file_name)) or {
-		eprintln('failed to create file $file_name')
+		eprintln('failed to create file ${file_name}')
 		return
 	}
 	// We use the standard write_bytes function to write the payload and
@@ -182,7 +182,7 @@ fn test_write_and_read_bytes() {
 	file_write.close()
 	assert u64(payload.len) == os.file_size(file_name)
 	mut file_read := os.open(os.real_path(file_name)) or {
-		eprintln('failed to open file $file_name')
+		eprintln('failed to open file ${file_name}')
 		return
 	}
 	// We only need to test read_bytes because this function calls
@@ -323,7 +323,7 @@ fn test_cp() {
 	old_file_name := 'cp_example.txt'
 	new_file_name := 'cp_new_example.txt'
 	os.write_file(old_file_name, 'Test data 1 2 3, V is awesome #$%^[]!~⭐') or { panic(err) }
-	os.cp(old_file_name, new_file_name) or { panic('$err') }
+	os.cp(old_file_name, new_file_name) or { panic('${err}') }
 	old_file := os.read_file(old_file_name) or { panic(err) }
 	new_file := os.read_file(new_file_name) or { panic(err) }
 	assert old_file == new_file

vlib/os/os_windows.c.v

@@ -167,11 +167,11 @@ pub fn ls(path string) ![]string {
 	// }
 	// C.FindClose(h_find_dir)
 	if !is_dir(path) {
-		return error('ls() couldnt open dir "$path": directory does not exist')
+		return error('ls() couldnt open dir "${path}": directory does not exist')
 	}
 	// NOTE: Should eventually have path struct & os dependant path seperator (eg os.PATH_SEPERATOR)
 	// we need to add files to path eg. c:\windows\*.dll or :\windows\*
-	path_files := '$path\\*'
+	path_files := '${path}\\*'
 	// NOTE:TODO: once we have a way to convert utf16 wide character to utf8
 	// we should use FindFirstFileW and FindNextFileW
 	h_find_files := C.FindFirstFile(path_files.to_wide(), voidptr(&find_file_data))
@@ -196,7 +196,7 @@ pub fn mkdir(path string, params MkdirParams) ! {
 	}
 	apath := real_path(path)
 	if !C.CreateDirectory(apath.to_wide(), 0) {
-		return error('mkdir failed for "$apath", because CreateDirectory returned: ' +
+		return error('mkdir failed for "${apath}", because CreateDirectory returned: ' +
 			get_error_msg(int(C.GetLastError())))
 	}
 }
@@ -311,7 +311,7 @@ pub fn raw_execute(cmd string) Result {
 		error_msg := get_error_msg(error_num)
 		return Result{
 			exit_code: error_num
-			output: 'exec failed (CreatePipe): $error_msg'
+			output: 'exec failed (CreatePipe): ${error_msg}'
 		}
 	}
 	set_handle_info_ok := C.SetHandleInformation(child_stdout_read, C.HANDLE_FLAG_INHERIT,
@@ -321,7 +321,7 @@ pub fn raw_execute(cmd string) Result {
 		error_msg := get_error_msg(error_num)
 		return Result{
 			exit_code: error_num
-			output: 'exec failed (SetHandleInformation): $error_msg'
+			output: 'exec failed (SetHandleInformation): ${error_msg}'
 		}
 	}
 	proc_info := ProcessInformation{}
@@ -345,7 +345,7 @@ pub fn raw_execute(cmd string) Result {
 		error_msg := get_error_msg(error_num)
 		return Result{
 			exit_code: error_num
-			output: 'exec failed (CreateProcess) with code $error_num: $error_msg cmd: $cmd'
+			output: 'exec failed (CreateProcess) with code ${error_num}: ${error_msg} cmd: ${cmd}'
 		}
 	}
 	C.CloseHandle(child_stdin)
@@ -496,7 +496,7 @@ pub fn loginname() string {
 // by creating an empty file in it, then deleting it.
 pub fn ensure_folder_is_writable(folder string) ! {
 	if !exists(folder) {
-		return error_with_code('`$folder` does not exist', 1)
+		return error_with_code('`${folder}` does not exist', 1)
 	}
 	if !is_dir(folder) {
 		return error_with_code('`folder` is not a folder', 2)
@@ -504,7 +504,7 @@ pub fn ensure_folder_is_writable(folder string) ! {
 	tmp_folder_name := 'tmp_perm_check_pid_' + getpid().str()
 	tmp_perm_check := join_path_single(folder, tmp_folder_name)
 	write_file(tmp_perm_check, 'test') or {
-		return error_with_code('cannot write to folder "$folder": $err', 3)
+		return error_with_code('cannot write to folder "${folder}": ${err}', 3)
 	}
 	rm(tmp_perm_check)!
 }

vlib/os/process.c.v

@@ -93,7 +93,7 @@ fn (mut p Process) _spawn() int {
 		p.env = []string{}
 		current_environment := environ()
 		for k, v in current_environment {
-			p.env << '$k=$v'
+			p.env << '${k}=${v}'
 		}
 	}
 	mut pid := 0
@@ -177,7 +177,7 @@ pub fn (mut p Process) stderr_read() string {
 // _check_redirection_call - should be called just by stdxxx methods
 fn (mut p Process) _check_redirection_call(fn_name string) {
 	if !p.use_stdio_ctl {
-		panic('Call p.set_redirect_stdio() before calling p.$fn_name')
+		panic('Call p.set_redirect_stdio() before calling p.${fn_name}')
 	}
 	if p.status == .not_started {
 		panic('Call p.${fn_name}() after you have called p.run()')

vlib/os/process.js.v

@@ -114,7 +114,7 @@ pub fn (mut p Process) stdout_slurp() string {
 // _check_redirection_call - should be called just by stdxxx methods
 fn (mut p Process) check_redirection_call(fn_name string) {
 	if !p.use_stdio_ctl {
-		panic('Call p.set_redirect_stdio() before calling p.$fn_name')
+		panic('Call p.set_redirect_stdio() before calling p.${fn_name}')
 	}
 	if p.status == .not_started {
 		panic('Call p.${fn_name}() after you have called p.run()')

vlib/os/process.v

@@ -64,7 +64,7 @@ pub fn (mut p Process) set_environment(envs map[string]string) {
 	p.env_is_custom = true
 	p.env = []string{}
 	for k, v in envs {
-		p.env << '$k=$v'
+		p.env << '${k}=${v}'
 	}
 	return
 }

vlib/os/process_test.v

@@ -32,7 +32,7 @@ fn testsuite_end() {
 
 fn test_getpid() {
 	pid := os.getpid()
-	eprintln('current pid: $pid')
+	eprintln('current pid: ${pid}')
 	assert pid != 0
 }
 
@@ -49,7 +49,7 @@ fn test_run() {
 			break
 		}
 		$if trace_process_output ? {
-			os.system('ps -opid= -oppid= -ouser= -onice= -of= -ovsz= -orss= -otime= -oargs= -p $p.pid')
+			os.system('ps -opid= -oppid= -ouser= -onice= -of= -ovsz= -orss= -otime= -oargs= -p ${p.pid}')
 		}
 		time.sleep(50 * time.millisecond)
 		i++
@@ -58,7 +58,7 @@ fn test_run() {
 	assert p.code == 0
 	assert p.status == .exited
 	//
-	eprintln('polling iterations: $i')
+	eprintln('polling iterations: ${i}')
 	assert i < 50
 	p.close()
 }
@@ -86,8 +86,8 @@ fn test_slurping_output() {
 	p.close()
 	$if trace_process_output ? {
 		eprintln('---------------------------')
-		eprintln('p output: "$output"')
-		eprintln('p errors: "$errors"')
+		eprintln('p output: "${output}"')
+		eprintln('p errors: "${errors}"')
 		eprintln('---------------------------')
 	}
 	// dump(output)

vlib/os/process_windows.c.v

@@ -25,7 +25,7 @@ fn failed_cfn_report_error(ok bool, label string) {
 	}
 	error_num := int(C.GetLastError())
 	error_msg := get_error_msg(error_num)
-	eprintln('failed $label: $error_msg')
+	eprintln('failed ${label}: ${error_msg}')
 	exit(1)
 }
 
@@ -94,7 +94,7 @@ fn (mut p Process) win_spawn_process() int {
 		start_info.h_std_error = wdata.child_stderr_write
 		start_info.dw_flags = u32(C.STARTF_USESTDHANDLES)
 	}
-	cmd := '$p.filename ' + p.args.join(' ')
+	cmd := '${p.filename} ' + p.args.join(' ')
 	C.ExpandEnvironmentStringsW(cmd.to_wide(), voidptr(&wdata.command_line[0]), 32768)
 
 	mut creation_flags := int(C.NORMAL_PRIORITY_CLASS)
@@ -171,7 +171,7 @@ fn (mut p Process) win_is_alive() bool {
 ///////////////
 
 fn (mut p Process) win_write_string(idx int, s string) {
-	panic('Process.write_string $idx is not implemented yet')
+	panic('Process.write_string ${idx} is not implemented yet')
 }
 
 fn (mut p Process) win_read_string(idx int, maxbytes int) (string, int) {

vlib/os/signal.js.v

@@ -2,7 +2,7 @@ module os
 
 fn signal_str(signal Signal) string {
 	mut result := signal.str().to_upper()
-	result = 'SIG$result'
+	result = 'SIG${result}'
 	return result
 }
 
@@ -103,7 +103,7 @@ fn signal_from_str(str JS.String) Signal {
 			Signal.sys
 		}
 		else {
-			panic('unknown signal: $s')
+			panic('unknown signal: ${s}')
 		}
 	}
 }