vlib: refactor empty string checks to use s == '' or s != '', instead of s.len == 0 (#21300)

cmd/tools/vcomplete.v

@@ -316,7 +316,7 @@ fn auto_complete(args []string) {
 	if args.len <= 1 || args[0] != 'complete' {
 		if args.len == 1 {
 			shell_path := os.getenv('SHELL')
-			if shell_path.len > 0 {
+			if shell_path != '' {
 				shell_name := os.file_name(shell_path).to_lower()
 				if shell_name in auto_complete_shells {
 					println(setup_for_shell(shell_name))

cmd/tools/vdoc/files.v

@@ -27,7 +27,7 @@ fn get_ignore_paths(path string) ![]string {
 }
 
 fn is_included(path string, ignore_paths []string) bool {
-	if path.len == 0 {
+	if path == '' {
 		return true
 	}
 	for ignore_path in ignore_paths {

cmd/tools/vdoc/html.v

@@ -317,7 +317,7 @@ ${tabs(2)}<script src="${vd.assets['dark_mode_js']}"></script>'
 
 fn get_src_link(repo_url string, file_name string, line_nr int) string {
 	mut url := urllib.parse(repo_url) or { return '' }
-	if url.path.len <= 1 || file_name.len == 0 {
+	if url.path.len <= 1 || file_name == '' {
 		return ''
 	}
 	url.path = url.path.trim_right('/') + match url.host {
@@ -530,7 +530,7 @@ fn doc_node_html(dn doc.DocNode, link string, head bool, include_examples bool,
 		hash_link = ' <a href="#${node_id}">#</a>'
 	}
 	dnw.writeln('${tabs(2)}<section id="${node_id}" class="doc-node${node_class}">')
-	if dn.name.len > 0 {
+	if dn.name != '' {
 		if dn.kind == .const_group {
 			dnw.write_string('${tabs(3)}<div class="title"><${head_tag}>${sym_name}${hash_link}</${head_tag}>')
 		} else {
@@ -571,7 +571,7 @@ fn doc_node_html(dn doc.DocNode, link string, head bool, include_examples bool,
 }
 
 fn write_toc(dn doc.DocNode, mut toc strings.Builder) {
-	mut toc_slug := if dn.name.len == 0 || dn.content.len == 0 { '' } else { slug(dn.name) }
+	mut toc_slug := if dn.name == '' || dn.content.len == 0 { '' } else { slug(dn.name) }
 	if toc_slug == '' && dn.children.len > 0 {
 		if dn.children[0].name == '' {
 			toc_slug = slug(dn.name)

cmd/tools/vdoc/main.v

@@ -49,7 +49,7 @@ fn main() {
 	}
 	args := os.args[2..].clone()
 	cfg := parse_arguments(args)
-	if cfg.input_path.len == 0 {
+	if cfg.input_path == '' {
 		eprintln('vdoc: No input path found.')
 		exit(1)
 	}
@@ -172,7 +172,7 @@ fn parse_arguments(args []string) Config {
 				cfg.is_verbose = true
 			}
 			else {
-				if cfg.input_path.len < 1 {
+				if cfg.input_path == '' {
 					cfg.input_path = arg
 				} else if !cfg.is_multi {
 					// Symbol name filtering should not be enabled

cmd/tools/vdoc/markdown.v

@@ -29,7 +29,7 @@ fn (vd VDoc) gen_markdown(d doc.Doc, with_toc bool) string {
 fn (vd VDoc) write_markdown_content(contents []doc.DocNode, mut cw strings.Builder, mut hw strings.Builder, indent int, with_toc bool) {
 	cfg := vd.cfg
 	for cn in contents {
-		if with_toc && cn.name.len > 0 {
+		if with_toc && cn.name != '' {
 			hw.writeln(' '.repeat(2 * indent) + '- [${slug(cn.name)}](#${cn.name})')
 			cw.writeln('## ${cn.name}')
 		}

cmd/tools/vdoc/vdoc.v

@@ -260,7 +260,7 @@ fn (mut vd VDoc) generate_docs_from_file() {
 		path: cfg.output_path
 		typ: cfg.output_type
 	}
-	if out.path.len == 0 {
+	if out.path == '' {
 		if cfg.output_type == .unset {
 			out.typ = .ansi
 		} else {
@@ -348,7 +348,7 @@ fn (mut vd VDoc) generate_docs_from_file() {
 		exit(1)
 	}
 	vd.vprintln('Rendering docs...')
-	if out.path.len == 0 || out.path == 'stdout' || out.path == '-' {
+	if out.path == '' || out.path == 'stdout' || out.path == '-' {
 		if out.typ == .html {
 			vd.render_static_html(out)
 		}

cmd/tools/vfmt.v

@@ -214,7 +214,7 @@ fn (mut foptions FormatOptions) find_diff_cmd() string {
 }
 
 fn (mut foptions FormatOptions) post_process_file(file string, formatted_file_path string) ! {
-	if formatted_file_path.len == 0 {
+	if formatted_file_path == '' {
 		return
 	}
 	fc := os.read_file(file) or {

cmd/tools/vls.v

@@ -299,7 +299,7 @@ fn (upd VlsUpdater) find_ls_path() !string {
 	if 'server_path' in manifest {
 		server_path := manifest['server_path'] or { return error('none') }
 		if server_path is string {
-			if server_path.len == 0 {
+			if server_path == '' {
 				return error('none')
 			}
 
@@ -361,7 +361,7 @@ fn (mut upd VlsUpdater) parse(mut fp flag.FlagParser) ! {
 	}
 
 	if upd.pass_to_ls {
-		if upd.ls_path.len == 0 {
+		if upd.ls_path == '' {
 			if ls_path := upd.find_ls_path() {
 				if !upd.is_force && upd.setup_kind == .install {
 					return error_with_code('VLS was already installed.', 102)
@@ -445,7 +445,7 @@ fn (upd VlsUpdater) cli_error(err IError) {
 }
 
 fn (upd VlsUpdater) check_installation() {
-	if upd.ls_path.len == 0 {
+	if upd.ls_path == '' {
 		upd.log('Language server is not installed')
 	} else {
 		upd.log('Language server is installed at: ${upd.ls_path}'.split(r'\').join(r'\\'))

cmd/tools/vwhere/finder_utils.v

@@ -143,7 +143,7 @@ fn maybe_color(term_color fn (string) string, str string) string {
 }
 
 fn collect_v_files(path string, recursive bool) ![]string {
-	if path.len == 0 {
+	if path == '' {
 		return error('path cannot be empty')
 	}
 	if !os.is_dir(path) {

examples/vcasino/vcasino.v

@@ -47,7 +47,7 @@ fn get_bet_nbr() int {
 		println('Reminder: odd numbers are red and even are black.')
 		println('Type the number you want to bet on (between 0 and 49):')
 		line := os.get_line().trim_space()
-		if line.len < 1 {
+		if line == '' {
 			println('error: empty line.')
 			continue
 		}
@@ -70,7 +70,7 @@ fn get_bet(money int) int {
 	for bet <= 0 || bet > money {
 		println('You have ${money} V. Type in the amount of your bet:')
 		line := os.get_line().trim_space()
-		if line.len < 1 {
+		if line == '' {
 			println('error: empty line.')
 			continue
 		}

examples/viewer/file_scan.v

@@ -139,7 +139,7 @@ fn (item_list Item_list) get_file_path() string {
 	if item_list.lst.len <= 0 || item_list.n_item <= 0 {
 		return ''
 	}
-	if item_list.lst[item_list.item_index].path.len > 0 {
+	if item_list.lst[item_list.item_index].path != '' {
 		return '${item_list.lst[item_list.item_index].path}${item_list.path_sep}${item_list.lst[item_list.item_index].name}'
 	}
 	return item_list.lst[item_list.item_index].name

examples/viewer/view.v

@@ -296,7 +296,7 @@ pub fn load_image(mut app App) {
 	}
 
 	file_path := app.item_list.get_file_path()
-	if file_path.len > 0 {
+	if file_path != '' {
 		// println("${app.item_list.lst[app.item_list.item_index]} $file_path ${app.item_list.lst.len}")
 		app.texture, app.sampler, app.img_w, app.img_h = app.load_texture_from_file(file_path)
 		app.img_ratio = f32(app.img_w) / f32(app.img_h)

examples/xvweb/todo/main.v

@@ -50,7 +50,7 @@ pub fn (app &App) create_todo(mut ctx Context, name string) vweb.Result {
 	// we could also access the name field by doing `name := ctx.form['name']`
 
 	// validate input field
-	if name.len == 0 {
+	if name == '' {
 		// set a form error
 		ctx.form_error = 'You must fill in all the fields!'
 		// send a HTTP 400 response code indicating that the form fields are incorrect

vlib/builtin/js/string.js.v

@@ -287,7 +287,7 @@ pub fn (s string) u8() u64 {
 // Example: assert ' Hello V d'.trim_right(' d') == ' Hello V'
 @[direct_array_access]
 pub fn (s string) trim_right(cutset string) string {
-	if s.len < 1 || cutset.len < 1 {
+	if s == '' || cutset == '' {
 		return s.clone()
 	}
 
@@ -317,7 +317,7 @@ pub fn (s string) trim_right(cutset string) string {
 // Example: assert 'd Hello V developer'.trim_left(' d') == 'Hello V developer'
 @[direct_array_access]
 pub fn (s string) trim_left(cutset string) string {
-	if s.len < 1 || cutset.len < 1 {
+	if s == '' || cutset == '' {
 		return s.clone()
 	}
 	mut pos := 0
@@ -924,7 +924,7 @@ pub fn (s string) reverse() string {
 }
 
 pub fn (s string) trim(cutset string) string {
-	if s.len < 1 || cutset.len < 1 {
+	if s == '' || cutset == '' {
 		return s.clone()
 	}
 	mut pos_left := 0

vlib/builtin/string.v

@@ -1678,7 +1678,7 @@ pub fn (s string) trim_space() string {
 // trim strips any of the characters given in `cutset` from the start and end of the string.
 // Example: assert ' ffHello V ffff'.trim(' f') == 'Hello V'
 pub fn (s string) trim(cutset string) string {
-	if s.len < 1 || cutset.len < 1 {
+	if s == '' || cutset == '' {
 		return s.clone()
 	}
 	left, right := s.trim_indexes(cutset)
@@ -1719,7 +1719,7 @@ pub fn (s string) trim_indexes(cutset string) (int, int) {
 // Example: assert 'd Hello V developer'.trim_left(' d') == 'Hello V developer'
 @[direct_array_access]
 pub fn (s string) trim_left(cutset string) string {
-	if s.len < 1 || cutset.len < 1 {
+	if s == '' || cutset == '' {
 		return s.clone()
 	}
 	mut pos := 0

vlib/compress/szip/szip.c.v

@@ -95,7 +95,7 @@ fn (om OpenMode) to_u8() u8 {
 // level: can be any value of the CompressionLevel enum.
 // mode: can be any value of the OpenMode enum.
 pub fn open(name string, level CompressionLevel, mode OpenMode) !&Zip {
-	if name.len == 0 {
+	if name == '' {
 		return error('szip: name of file empty')
 	}
 	p_zip := unsafe { &Zip(C.zip_open(&char(name.str), int(level), char(mode.to_u8()))) }

vlib/dl/loader/loader.v

@@ -68,7 +68,7 @@ pub:
 fn new_dynamic_lib_loader(conf DynamicLibLoaderConfig) !&DynamicLibLoader {
 	mut paths := []string{}
 
-	if conf.env_path.len > 0 {
+	if conf.env_path != '' {
 		if env_path := os.getenv_opt(conf.env_path) {
 			paths << env_path.split(os.path_delimiter)
 		}

vlib/encoding/xml/parser.v

@@ -179,7 +179,7 @@ fn parse_entity(contents string) !(DTDEntity, string) {
 	entity_contents := contents[xml.entity_len..entity_end]
 
 	name := entity_contents.trim_left(' \t\n').all_before(' ')
-	if name.len == 0 {
+	if name == '' {
 		return error('Entity is missing name.')
 	}
 	value := entity_contents.all_after_first(name).trim_space().trim('"\'')
@@ -221,7 +221,7 @@ fn parse_element(contents string) !(DTDElement, string) {
 	}
 
 	name := element_contents[name_span.start..name_span.end].trim_left(' \t\n')
-	if name.len == 0 {
+	if name == '' {
 		return error('Element is missing name.')
 	}
 	definition_string := element_contents.all_after_first(name).trim_space().trim('"\'')

vlib/encoding/xml/validation.v

@@ -75,7 +75,7 @@ pub fn (doc XMLDocument) validate() !XMLDocument {
 			new_root := doc.root.validate(elements, entities)!
 
 			// Check the DOCTYPE name matches the root name
-			if doc.doctype.name.len > 0 && doc.doctype.name != new_root.name {
+			if doc.doctype.name != '' && doc.doctype.name != new_root.name {
 				return error('Root element ${new_root.name} does not match DOCTYPE ${doc.doctype.name}')
 			}
 

vlib/net/html/dom.v

@@ -36,7 +36,7 @@ fn (mut dom DocumentObjectModel) print_debug(data string) {
 
 @[inline]
 fn is_close_tag(tag &Tag) bool {
-	return tag.name.len > 0 && tag.name[0] == `/`
+	return tag.name != '' && tag.name[0] == `/`
 }
 
 fn (mut dom DocumentObjectModel) where_is(item_name string, attribute_name string) int {
@@ -138,7 +138,7 @@ fn (mut dom DocumentObjectModel) construct(tag_list []&Tag) {
 				stack.push(root_index)
 			}
 			dom.print_debug('Removed ' + temp_string + ' -- ' + tag_list[temp_int].name)
-		} else if tag.name.len > 0 {
+		} else if tag.name != '' {
 			dom.add_tag_attribute(tag) // error here
 			dom.add_tag_by_attribute(tag)
 			dom.add_tag_by_type(tag)

vlib/net/html/parser.v

@@ -100,7 +100,7 @@ fn (mut parser Parser) generate_tag() {
 	if parser.lexical_attributes.open_tag {
 		return
 	}
-	if parser.lexical_attributes.current_tag.name.len > 0
+	if parser.lexical_attributes.current_tag.name != ''
 		|| parser.lexical_attributes.current_tag.content.len > 0 {
 		parser.tags << parser.lexical_attributes.current_tag
 	}

vlib/net/html/tag.v

@@ -52,7 +52,7 @@ pub fn (tag &Tag) str() string {
 	html_str.write_string('<${tag.name}')
 	for key, value in tag.attributes {
 		html_str.write_string(' ${key}')
-		if value.len > 0 {
+		if value != '' {
 			html_str.write_string('="${value}"')
 		}
 	}

vlib/net/http/file/folder_index.v

@@ -60,7 +60,7 @@ fn write_page_table(mut sb strings.Builder, uri_path string, requested_file_path
 	sb.writeln('<th align="left" style="width: 200px">Last modified</th>')
 	sb.writeln('<th align="left">Name</th>')
 	sb.writeln('</tr>')
-	if uri_path.len == 0 {
+	if uri_path == '' {
 		sb.writeln('<tr>')
 		sb.writeln('<td>---</td>')
 		sb.writeln('<td>---</td>')

vlib/net/http/http_test.v

@@ -17,7 +17,7 @@ fn test_http_get_from_vlang_utc_now() {
 		println('Test getting current time from ${url} by http.get')
 		res := http.get(url) or { panic(err) }
 		assert res.status() == .ok
-		assert res.body.len > 0
+		assert res.body != ''
 		assert res.body.int() > 1566403696
 		println('Current time is: ${res.body.int()}')
 	}
@@ -39,7 +39,7 @@ fn test_public_servers() {
 		println('Testing http.get on public url: ${url} ')
 		res := http.get(url) or { panic(err) }
 		assert res.status() == .ok
-		assert res.body.len > 0
+		assert res.body != ''
 	}
 }
 
@@ -51,6 +51,6 @@ fn test_relative_redirects() {
 	} // tempfix periodic: httpbin relative redirects are broken
 	res := http.get('https://httpbin.org/relative-redirect/3?abc=xyz') or { panic(err) }
 	assert res.status() == .ok
-	assert res.body.len > 0
+	assert res.body != ''
 	assert res.body.contains('"abc": "xyz"')
 }

vlib/net/http/response.v

@@ -131,7 +131,7 @@ pub fn new_response(conf ResponseConfig) Response {
 		body: conf.body
 		header: conf.header
 	}
-	if resp.body.len > 0 && !resp.header.contains(.content_length) {
+	if resp.body != '' && !resp.header.contains(.content_length) {
 		resp.header.add(.content_length, resp.body.len.str())
 	}
 	resp.set_status(conf.status)

vlib/os/filepath.v

@@ -18,7 +18,7 @@ const dot_str = '.'
 
 // is_abs_path returns `true` if the given `path` is absolute.
 pub fn is_abs_path(path string) bool {
-	if path.len == 0 {
+	if path == '' {
 		return false
 	}
 	$if windows {
@@ -32,7 +32,7 @@ pub fn is_abs_path(path string) bool {
 // and returns the absolute path representation.
 pub fn abs_path(path string) string {
 	wd := getwd()
-	if path.len == 0 {
+	if path == '' {
 		return wd
 	}
 	npath := norm_path(path)
@@ -57,7 +57,7 @@ pub fn abs_path(path string) string {
 // - the last path separator
 @[direct_array_access]
 pub fn norm_path(path string) string {
-	if path.len == 0 {
+	if path == '' {
 		return os.dot_str
 	}
 	rooted := is_abs_path(path)
@@ -69,7 +69,7 @@ pub fn norm_path(path string) string {
 		volume = volume.replace(os.fslash_str, path_separator)
 	}
 	cpath := clean_path(path[volume_len..])
-	if cpath.len == 0 && volume_len == 0 {
+	if cpath == '' && volume_len == 0 {
 		return os.dot_str
 	}
 	spath := cpath.split(path_separator)
@@ -131,7 +131,7 @@ pub fn norm_path(path string) string {
 // An error is returned if there is no existing part of the given `path`.
 pub fn existing_path(path string) !string {
 	err := error('path does not exist')
-	if path.len == 0 {
+	if path == '' {
 		return err
 	}
 	if exists(path) {
@@ -164,7 +164,7 @@ pub fn existing_path(path string) !string {
 				recent_path = curr_path
 				continue
 			}
-			if recent_path.len == 0 {
+			if recent_path == '' {
 				break
 			}
 			return recent_path
@@ -180,7 +180,7 @@ pub fn existing_path(path string) !string {
 // - redundant separators
 // - the last path separator
 fn clean_path(path string) string {
-	if path.len == 0 {
+	if path == '' {
 		return os.empty_str
 	}
 	mut sb := strings.new_builder(path.len)

vlib/os/os.c.v

@@ -269,7 +269,7 @@ pub fn cp(src string, dst string) ! {
 // Note: os.vfopen is useful for compatibility with C libraries, that expect `FILE *`.
 // If you write pure V code, os.create or os.open are more convenient.
 pub fn vfopen(path string, mode string) !&C.FILE {
-	if path.len == 0 {
+	if path == '' {
 		return error('vfopen called with ""')
 	}
 	mut fp := unsafe { nil }

vlib/os/os.v

@@ -62,7 +62,7 @@ fn executable_fallback() string {
 		} else {
 			// no choice but to try to walk the PATH folders :-| ...
 			foundpath := find_abs_path_of_executable(exepath) or { '' }
-			if foundpath.len > 0 {
+			if foundpath != '' {
 				exepath = foundpath
 			}
 		}
@@ -641,7 +641,7 @@ fn impl_walk_ext(path string, ext string, mut out []string) {
 // since it does not recurse, but processes them iteratively.
 // For listing only one level deep, see: `os.ls`
 pub fn walk(path string, f fn (string)) {
-	if path.len == 0 {
+	if path == '' {
 		return
 	}
 	if !is_dir(path) {
@@ -679,7 +679,7 @@ pub type FnWalkContextCB = fn (voidptr, string)
 // since it does not recurse, but processes them iteratively.
 // For listing only one level deep, see: `os.ls`
 pub fn walk_with_context(path string, context voidptr, fcb FnWalkContextCB) {
-	if path.len == 0 {
+	if path == '' {
 		return
 	}
 	if !is_dir(path) {

vlib/os/os_nix.c.v

@@ -296,7 +296,7 @@ fn init_os_args(argc int, argv &&u8) []string {
 //   }
 // ```
 pub fn ls(path string) ![]string {
-	if path.len == 0 {
+	if path == '' {
 		return error('ls() expects a folder, not an empty string')
 	}
 	mut res := []string{cap: 50}

vlib/os/os_windows.c.v

@@ -162,7 +162,7 @@ pub fn utime(path string, actime int, modtime int) ! {
 }
 
 pub fn ls(path string) ![]string {
-	if path.len == 0 {
+	if path == '' {
 		return error('ls() expects a folder, not an empty string')
 	}
 	mut find_file_data := Win32finddata{}

vlib/picohttpparser/picohttpparser.v

@@ -53,7 +53,7 @@ fn (mut r Request) phr_parse_request_path(buf_start &u8, buf_end &u8, mut pret P
 		}
 	}
 	// validate
-	if method.len == 0 || path.len == 0 {
+	if method == '' || path == '' {
 		pret.ret = -1
 		pret.err = 'error parsing request: invalid method or path'
 		return
@@ -81,7 +81,7 @@ fn (mut r Request) phr_parse_request_path_pipeline(buf_start &u8, buf_end &u8, m
 		buf += pret.ret
 	}
 	// validate
-	if method.len == 0 || path.len == 0 {
+	if method == '' || path == '' {
 		pret.ret = -1
 		pret.err = 'error parsing request: invalid method or path'
 		return

vlib/strconv/atoi.v

@@ -35,7 +35,7 @@ pub fn common_parse_uint(s string, _base int, _bit_size int, error_on_non_digit
 // the second returned value contains the error code (0 = OK, >1 = index of first non-parseable character + 1, -1 = wrong base, -2 = wrong bit size, -3 = overflow)
 @[direct_array_access]
 pub fn common_parse_uint2(s string, _base int, _bit_size int) (u64, int) {
-	if s.len < 1 {
+	if s == '' {
 		return u64(0), 1
 	}
 
@@ -156,7 +156,7 @@ pub fn parse_uint(s string, _base int, _bit_size int) !u64 {
 // to stop on non or invalid digit characters and return with an error
 @[direct_array_access]
 pub fn common_parse_int(_s string, base int, _bit_size int, error_on_non_digit bool, error_on_high_digit bool) !i64 {
-	if _s.len < 1 {
+	if _s == '' {
 		// return error('parse_int: syntax error $s')
 		return i64(0)
 	}

vlib/strings/builder.c.v

@@ -195,7 +195,7 @@ pub fn (mut b Builder) writeln(s string) {
 	// for c in s {
 	// b.buf << c
 	// }
-	if s.len > 0 {
+	if s != '' {
 		unsafe { b.push_many(s.str, s.len) }
 	}
 	// b.buf << []u8(s)  // TODO

vlib/strings/builder.js.v

@@ -45,7 +45,7 @@ pub fn (b &Builder) byte_at(n int) u8 {
 }
 
 pub fn (mut b Builder) write_string(s string) {
-	if s.len == 0 {
+	if s == '' {
 		return
 	}
 
@@ -55,7 +55,7 @@ pub fn (mut b Builder) write_string(s string) {
 }
 
 pub fn (mut b Builder) writeln(s string) {
-	if s.len > 0 {
+	if s != '' {
 		b.write_string(s)
 	}
 

vlib/szip/szip.c.v

@@ -97,7 +97,7 @@ fn (om OpenMode) to_u8() u8 {
 // level: can be any value of the CompressionLevel enum.
 // mode: can be any value of the OpenMode enum.
 pub fn open(name string, level CompressionLevel, mode OpenMode) !&Zip {
-	if name.len == 0 {
+	if name == '' {
 		return error('szip: name of file empty')
 	}
 	p_zip := unsafe { &Zip(C.zip_open(&char(name.str), int(level), char(mode.to_u8()))) }

vlib/v/ast/table.v

@@ -138,7 +138,7 @@ pub fn (t &Table) fn_type_source_signature(f &Fn) string {
 			sig += 'mut '
 		}
 		// Note: arg name is only added for fmt, else it would causes errors with generics
-		if t.is_fmt && arg.name.len > 0 {
+		if t.is_fmt && arg.name != '' {
 			sig += '${arg.name} '
 		}
 		arg_type_sym := t.sym(arg.typ)
@@ -1196,13 +1196,13 @@ pub fn (mut t Table) find_or_register_multi_return(mr_typs []Type) int {
 }
 
 pub fn (mut t Table) find_or_register_fn_type(f Fn, is_anon bool, has_decl bool) int {
-	name := if f.name.len == 0 { 'fn ${t.fn_type_source_signature(f)}' } else { f.name.clone() }
-	cname := if f.name.len == 0 {
+	name := if f.name == '' { 'fn ${t.fn_type_source_signature(f)}' } else { f.name.clone() }
+	cname := if f.name == '' {
 		'anon_fn_${t.fn_type_signature(f)}'
 	} else {
 		util.no_dots(f.name.clone()).replace_each(ast.fn_type_escape_seq)
 	}
-	anon := f.name.len == 0 || is_anon
+	anon := f.name == '' || is_anon
 	existing_idx := t.type_idxs[name]
 	if existing_idx > 0 && t.type_symbols[existing_idx].kind != .placeholder {
 		return existing_idx

vlib/v/ast/types.v

@@ -1359,7 +1359,7 @@ pub fn (t &Table) type_to_str_using_aliases(typ Type, import_aliases map[string]
 			} else {
 				if res.starts_with('fn (') {
 					// fn foo ()
-					has_names := info.func.params.any(it.name.len > 0)
+					has_names := info.func.params.any(it.name != '')
 					res = t.fn_signature_using_aliases(info.func, import_aliases,
 						type_only: !has_names
 					)

vlib/v/checker/check_types.v

@@ -466,7 +466,7 @@ fn (mut c Checker) check_matching_function_symbols(got_type_sym &ast.TypeSymbol,
 		if exp_arg_is_ptr != got_arg_is_ptr {
 			exp_arg_pointedness := if exp_arg_is_ptr { 'a pointer' } else { 'NOT a pointer' }
 			got_arg_pointedness := if got_arg_is_ptr { 'a pointer' } else { 'NOT a pointer' }
-			if exp_fn.name.len == 0 {
+			if exp_fn.name == '' {
 				c.add_error_detail('expected argument ${i + 1} to be ${exp_arg_pointedness}, but the passed argument ${
 					i + 1} is ${got_arg_pointedness}')
 			} else {

vlib/v/checker/fn.v

@@ -493,7 +493,7 @@ fn (mut c Checker) anon_fn(mut node ast.AnonFn) ast.Type {
 		c.error('anonymous function must declare a body', node.decl.pos)
 	}
 	for param in node.decl.params {
-		if param.name.len == 0 {
+		if param.name == '' {
 			c.error('use `_` to name an unused parameter', param.pos)
 		}
 	}
@@ -1107,7 +1107,7 @@ fn (mut c Checker) fn_call(mut node ast.CallExpr, mut continue_check &bool) ast.
 				node.pos)
 		}
 	}
-	if !func.is_pub && func.language == .v && func.name.len > 0 && func.mod.len > 0
+	if !func.is_pub && func.language == .v && func.name != '' && func.mod.len > 0
 		&& func.mod != c.mod && !c.pref.is_test {
 		c.error('function `${func.name}` is private', node.pos)
 	}

vlib/v/checker/struct.v

@@ -715,8 +715,8 @@ or use an explicit `unsafe{ a[..] }`, if you do not want a copy of the slice.',
 
 				// all the fields of initialized embedded struct are ignored, they are considered initialized
 				sym := c.table.sym(init_field.typ)
-				if init_field.name.len > 0 && init_field.name[0].is_capital()
-					&& sym.kind == .struct_ && sym.language == .v {
+				if init_field.name != '' && init_field.name[0].is_capital() && sym.kind == .struct_
+					&& sym.language == .v {
 					struct_fields := c.table.struct_fields(sym)
 					for struct_field in struct_fields {
 						inited_fields << struct_field.name
@@ -770,7 +770,7 @@ or use an explicit `unsafe{ a[..] }`, if you do not want a copy of the slice.',
 					continue
 				}
 				sym := c.table.sym(field.typ)
-				if field.name.len > 0 && field.name[0].is_capital() && sym.info is ast.Struct {
+				if field.name != '' && field.name[0].is_capital() && sym.info is ast.Struct {
 					// struct embeds
 					continue
 				}
@@ -930,7 +930,7 @@ fn (mut c Checker) check_ref_fields_initialized(struct_sym &ast.TypeSymbol, mut
 			if sym.language == .c {
 				continue
 			}
-			if field.name.len > 0 && field.name[0].is_capital() && sym.language == .v {
+			if field.name != '' && field.name[0].is_capital() && sym.language == .v {
 				// an embedded struct field
 				continue
 			}
@@ -972,7 +972,7 @@ fn (mut c Checker) check_ref_fields_initialized_note(struct_sym &ast.TypeSymbol,
 			if sym.language == .c {
 				continue
 			}
-			if field.name.len > 0 && field.name[0].is_capital() && sym.language == .v {
+			if field.name != '' && field.name[0].is_capital() && sym.language == .v {
 				// an embedded struct field
 				continue
 			}

vlib/v/doc/doc.v

@@ -201,7 +201,7 @@ pub fn (mut d Doc) stmt(mut stmt ast.Stmt, filename string) !DocNode {
 	if node.name.starts_with(d.orig_mod_name + '.') {
 		node.name = node.name.all_after(d.orig_mod_name + '.')
 	}
-	if node.name.len == 0 && node.comments.len == 0 && node.content.len == 0 {
+	if node.name == '' && node.comments.len == 0 && node.content.len == 0 {
 		return error('empty stmt')
 	}
 	match mut stmt {

vlib/v/gen/js/deep_copy.v

@@ -162,7 +162,7 @@ fn (mut g JsGen) gen_copy_for_struct(info ast.Struct, styp string, copy_fn_name
 	fn_builder.writeln('\tlet $tmp = new ${styp}({});')
 	for field in info.fields {
 		println(field)
-		if field.name.len == 0 {
+		if field.name == '' {
 
 		} else {
 			mut shall_copy := true

vlib/v/parser/fn.v

@@ -11,7 +11,7 @@ import os
 fn (mut p Parser) call_expr(language ast.Language, mod string) ast.CallExpr {
 	first_pos := p.tok.pos()
 	mut name := if language == .js { p.check_js_name() } else { p.check_name() }
-	mut is_static_type_method := language == .v && name.len > 0 && name[0].is_capital()
+	mut is_static_type_method := language == .v && name != '' && name[0].is_capital()
 		&& p.tok.kind == .dot
 	if is_static_type_method {
 		p.check(.dot)
@@ -782,7 +782,7 @@ fn (mut p Parser) anon_fn() ast.AnonFn {
 	_, generic_names := p.parse_generic_types()
 	params, _, is_variadic := p.fn_params()
 	for param in params {
-		if param.name.len == 0 && p.table.sym(param.typ).kind != .placeholder {
+		if param.name == '' && p.table.sym(param.typ).kind != .placeholder {
 			p.error_with_pos('use `_` to name an unused parameter', param.pos)
 		}
 		if param.name in inherited_vars_name {
@@ -1004,7 +1004,7 @@ fn (mut p Parser) fn_params() ([]ast.Param, bool, bool) {
 			name := p.check_name()
 			comments << p.eat_comments()
 			mut param_names := [name]
-			if name.len > 0 && p.fn_language == .v && name[0].is_capital() {
+			if name != '' && p.fn_language == .v && name[0].is_capital() {
 				p.error_with_pos('parameter name must not begin with upper case letter (`${param_names[0]}`)',
 					p.prev_tok.pos())
 			}

vlib/v/parser/parse_type.v

@@ -320,7 +320,7 @@ fn (mut p Parser) parse_fn_type(name string, generic_types []ast.Type) ast.Type
 		is_method: false
 		attrs: p.attrs
 	}
-	if has_generic && generic_types.len == 0 && name.len > 0 {
+	if has_generic && generic_types.len == 0 && name != '' {
 		p.error_with_pos('`${name}` type is generic fntype, must specify the generic type names, e.g. ${name}[T]',
 			fn_type_pos)
 	}

vlib/v/parser/parser.v

@@ -2790,9 +2790,8 @@ fn (mut p Parser) name_expr() ast.Expr {
 		// handle the easy cases first, then check for an already known V typename, not shadowed by a local variable
 		if (is_option || p.peek_tok.kind in [.lsbr, .lt, .lpar]) && (is_mod_cast
 			|| is_c_pointer_cast || is_c_type_cast || is_js_cast || is_generic_cast
-			|| (language == .v && name.len > 0 && (name[0].is_capital()
-			|| (!known_var && (name in p.table.type_idxs
-			|| name_w_mod in p.table.type_idxs))
+			|| (language == .v && name != '' && (name[0].is_capital() || (!known_var
+			&& (name in p.table.type_idxs || name_w_mod in p.table.type_idxs))
 			|| name.all_after_last('.')[0].is_capital()))) {
 			// MainLetter(x) is *always* a cast, as long as it is not `C.`
 			// TODO: handle C.stat()
@@ -3393,7 +3392,7 @@ fn (mut p Parser) parse_generic_types() ([]ast.Type, []string) {
 			p.check(.comma)
 		}
 		name := p.tok.lit
-		if name.len > 0 && !name[0].is_capital() {
+		if name != '' && !name[0].is_capital() {
 			p.error('generic parameter needs to be uppercase')
 		}
 		if name.len > 1 {

vlib/v/tests/results_test.v

@@ -75,7 +75,7 @@ fn test_unsafe_return_error() {
 }
 
 fn return_reference_type(path string) !&string {
-	if path.len == 0 {
+	if path == '' {
 		return error('vfopen called with ""')
 	}
 	str := ''

vlib/v/util/util.v

@@ -350,7 +350,7 @@ pub fn cached_read_source_file(path string) !string {
 	$if trace_cached_read_source_file ? {
 		println('cached_read_source_file            ${path}')
 	}
-	if path.len == 0 {
+	if path == '' {
 		unsafe { cache.sources.free() }
 		unsafe { free(cache) }
 		cache = &SourceCache(unsafe { nil })

vlib/v2/gen/v/gen.v

@@ -537,7 +537,7 @@ fn (mut g Gen) expr(expr ast.Expr) {
 		ast.InitExpr {
 			g.expr(expr.typ)
 			// with field names
-			if expr.fields.len > 0 && expr.fields[0].name.len > 0 {
+			if expr.fields.len > 0 && expr.fields[0].name != '' {
 				g.writeln('{')
 				in_init := g.in_init
 				g.in_init = true
@@ -886,7 +886,7 @@ fn (mut g Gen) attributes(attributes []ast.Attribute) {
 			g.write('if ')
 			g.expr(attribute.comptime_cond)
 		} else {
-			if attribute.name.len > 0 {
+			if attribute.name != '' {
 				g.write(attribute.name)
 				g.write(': ')
 			}
@@ -905,7 +905,7 @@ fn (mut g Gen) fn_type(typ ast.FnType) {
 	}
 	g.write('(')
 	for i, param in typ.params {
-		if param.name.len > 0 {
+		if param.name != '' {
 			g.write(param.name)
 			g.write(' ')
 		}

vlib/v2/types/types.v

@@ -498,7 +498,7 @@ fn (t Enum) name() string {
 fn (t FnType) name() string {
 	mut name := 'fn ('
 	for i, param in t.params {
-		if param.name.len > 0 {
+		if param.name != '' {
 			name += '${param.name} '
 		}
 		name += param.typ.name()

vlib/vweb/vweb.v

@@ -1059,7 +1059,7 @@ pub fn (mut ctx Context) mount_static_folder_at(directory_path string, mount_pat
 // and you have a file /var/share/myassets/main.css .
 // => That file will be available at URL: http://localhost/assets/main.css .
 pub fn (mut ctx Context) host_mount_static_folder_at(host string, directory_path string, mount_path string) bool {
-	if ctx.done || mount_path.len < 1 || mount_path[0] != `/` || !os.exists(directory_path) {
+	if ctx.done || mount_path == '' || mount_path[0] != `/` || !os.exists(directory_path) {
 		return false
 	}
 	dir_path := directory_path.trim_right('/')

vlib/x/templating/dtm/dynamic_template_manager.v

@@ -205,7 +205,7 @@ pub fn initialize(dtm_init_params DynamicTemplateManagerInitialisationParams) &D
 	}
 	if active_cache_handler {
 		// Control if cache folder created by user exist
-		if dir_path.len > 0 && os.exists(dir_path) && os.is_dir(dir_path) {
+		if dir_path != '' && os.exists(dir_path) && os.is_dir(dir_path) {
 			// WARNING: When setting the directory for caching files and for testing purposes,
 			// 'check_and_clear_cache_files' function will delete all "*.cache" or "*.tmp" files inside the specified cache directory. Ensure that
 			// directory used for the cache does not contain any important files.

vlib/x/ttf/text_block.v

@@ -78,7 +78,7 @@ pub fn (mut bmp BitMap) draw_text_block(text string, block Text_block) {
 			for c > 0 {
 				tmp_str := txt1[0..c].join(' ')
 				// println("tmp_str: ${tmp_str}")
-				if tmp_str.len < 1 {
+				if tmp_str == '' {
 					break
 				}
 

vlib/x/vweb/assets/assets.v

@@ -281,7 +281,7 @@ pub fn minify_css(css string) string {
 
 	for line in lines {
 		trimmed := line.trim_space()
-		if trimmed.len > 0 {
+		if trimmed != '' {
 			sb.write_string(trimmed)
 		}
 	}
@@ -301,7 +301,7 @@ pub fn minify_js(js string) string {
 
 	for line in lines {
 		trimmed := line.trim_space()
-		if trimmed.len > 0 {
+		if trimmed != '' {
 			sb.write_string(trimmed)
 			sb.write_u8(` `)
 		}

vlib/x/vweb/context.v

@@ -100,7 +100,7 @@ pub fn (mut ctx Context) send_response_to_client(mimetype string, response strin
 	// set Content-Type and Content-Length headers
 	mut custom_mimetype := if ctx.content_type.len == 0 { mimetype } else { ctx.content_type }
 	ctx.res.header.set(.content_type, custom_mimetype)
-	if ctx.res.body.len > 0 {
+	if ctx.res.body != '' {
 		ctx.res.header.set(.content_length, ctx.res.body.len.str())
 	}
 	// send vweb's closing headers

vlib/x/vweb/static_handler.v

@@ -81,7 +81,7 @@ pub fn (mut sh StaticHandler) mount_static_folder_at(directory_path string, moun
 // and you have a file /var/share/myassets/main.css .
 // => That file will be available at URL: http://localhost/assets/main.css .
 pub fn (mut sh StaticHandler) host_mount_static_folder_at(host string, directory_path string, mount_path string) !bool {
-	if mount_path.len < 1 || mount_path[0] != `/` {
+	if mount_path == '' || mount_path[0] != `/` {
 		return error('invalid mount path! The path should start with `/`')
 	} else if !os.exists(directory_path) {
 		return error('directory `${directory_path}` does not exist. The directory should be relative to the current working directory: ${os.getwd()}')