js: codegen fixes, W.I.P os availability for JS backend (#11281)

vlib/builtin/js/array.js.v

@@ -239,3 +239,7 @@ pub fn (a array) contains(key voidptr) bool {
 pub fn (mut a array) delete_last() {
 	#a.val.arr.pop();
 }
+
+[unsafe]
+pub fn (a array) free() {
+}

vlib/math/pow.js.v

@@ -1,3 +1,7 @@
 module math
 
 fn JS.Math.pow(x f64, y f64) f64
+
+pub fn pow(x f64, y f64) f64 {
+	return JS.Math.pow(x, y)
+}

vlib/os/environment.js.v

@@ -0,0 +1,37 @@
+module os
+
+$if js_node {
+	#const $ENV = $process.env
+} $else {
+	#const $ENV = {}
+}
+
+// setenv sets the value of an environment variable with `name` to `value`.
+pub fn setenv(key string, val string, overwrite bool) {
+	#if ($ENV[key] && !(overwrite.valueOf())) return;
+	#$ENV[key] = val + '';
+}
+
+// `getenv` returns the value of the environment variable named by the key.
+pub fn getenv(key string) string {
+	mut res := ''
+	#if ($ENV[key]) res = new builtin.string($ENV[key])
+
+	return res
+}
+
+// unsetenv clears an environment variable with `name`.
+pub fn unsetenv(name string) int {
+	#$ENV[name] = ""
+
+	return 1
+}
+
+pub fn environ() map[string]string {
+	mut res := map[string]string{}
+	#for (const key in $ENV) {
+	#res.map.set(key,$ENV[key])
+	#}
+
+	return res
+}

vlib/os/os.js.v

@@ -0,0 +1,97 @@
+module os
+
+#const $fs = require('fs');
+#const $path = require('path');
+
+pub const (
+	args           = []string{}
+	path_delimiter = '/'
+	path_separator = '/'
+)
+
+$if js_node {
+	#$process.argv.forEach(function(val,index) { args.arr[index] = new string(val); })
+}
+
+// real_path returns the full absolute path for fpath, with all relative ../../, symlinks and so on resolved.
+// See http://pubs.opengroup.org/onlinepubs/9699919799/functions/realpath.html
+// Also https://insanecoding.blogspot.com/2007/11/pathmax-simply-isnt.html
+// and https://insanecoding.blogspot.com/2007/11/implementing-realpath-in-c.html
+// NB: this particular rabbit hole is *deep* ...
+pub fn real_path(fpath string) string {
+	$if js_node {
+		mut res := ''
+		#res = new string( $fs.realpathSync(fpath))
+
+		return res
+	} $else {
+		return fpath
+	}
+}
+
+// flush will flush the stdout buffer.
+pub fn flush() {
+	$if js_node {
+		#$process.stdout.write('')
+	}
+}
+
+// chmod change file access attributes of `path` to `mode`.
+// Octals like `0o600` can be used.
+pub fn chmod(path string, mode int) {
+	$if js_node {
+		#$fs.chmodSync(''+path,mode.valueOf())
+	}
+}
+
+// chown changes the owner and group attributes of `path` to `owner` and `group`.
+// Octals like `0o600` can be used.
+pub fn chown(path string, owner int, group int) {
+	$if js_node {
+		#$fs.chownSync(''+path,owner.valueOf(),group.valueOf())
+	}
+}
+
+pub fn temp_dir() string {
+	mut res := ''
+	$if js_node {
+		#res = new builtin.string($os.tmpdir())
+	}
+	return res
+}
+
+pub fn home_dir() string {
+	mut res := ''
+	$if js_node {
+		#res = new builtin.string($os.homedir())
+	}
+	return res
+}
+
+// join_path returns a path as string from input string parameter(s).
+pub fn join_path(base string, dirs ...string) string {
+	mut result := []string{}
+	result << base.trim_right('\\/')
+	for d in dirs {
+		result << d
+	}
+	mut path_sep := ''
+	#path_sep = $path.sep;
+
+	res := result.join(path_sep)
+	return res
+}
+
+pub fn execute(cmd string) Result {
+	mut exit_code := 0
+	mut stdout := ''
+	#let commands = cmd.str.split(' ');
+	#let output = $child_process.spawnSync(commands[0],commands.slice(1,commands.length));
+	#exit_code = new builtin.int(output.status)
+	#stdout = new builtin.string(output.stdout + '')
+
+	return Result{
+		exit_code: exit_code
+		output: stdout
+	}
+}

vlib/os/os_js.js.v

@@ -0,0 +1,47 @@
+module os
+
+pub fn mkdir(path string) ?bool {
+	$if js_node {
+		if path == '.' {
+			return true
+		}
+		#$fs.mkdirSync(path.valueOf())
+
+		return true
+	} $else {
+		return false
+	}
+}
+
+pub fn is_dir(path string) bool {
+	res := false
+	#res.val = $fs.existsSync(path,str) && $fs.lstatSync(path.str).isDirectory()
+
+	return res
+}
+
+pub fn is_link(path string) bool {
+	res := false
+	#res.val = $fs.existsSync(path.str) && $fs.lstatSync(path.str).isSymbolicLink()
+
+	return res
+}
+
+pub fn exists(path string) bool {
+	res := false
+	#res.val = $fs.existsSync(path.str)
+
+	return res
+}
+
+pub fn ls(path string) ?[]string {
+	if !is_dir(path) {
+		return error('ls(): cannot open dir $dir')
+	}
+
+	result := []string{}
+	#let i = 0
+	#$fs.readdirSync(path.str).forEach((path) => result.arr[i++] = new builtin.string(path))
+
+	return result
+}

vlib/os/process.c.v

@@ -0,0 +1,248 @@
+module os
+
+// signal_kill - kills the process, after that it is no longer running
+pub fn (mut p Process) signal_kill() {
+	if p.status !in [.running, .stopped] {
+		return
+	}
+	p._signal_kill()
+	p.status = .aborted
+	return
+}
+
+// signal_pgkill - kills the whole process group
+pub fn (mut p Process) signal_pgkill() {
+	if p.status !in [.running, .stopped] {
+		return
+	}
+	p._signal_pgkill()
+	return
+}
+
+// signal_stop - stops the process, you can resume it with p.signal_continue()
+pub fn (mut p Process) signal_stop() {
+	if p.status != .running {
+		return
+	}
+	p._signal_stop()
+	p.status = .stopped
+	return
+}
+
+// signal_continue - tell a stopped process to continue/resume its work
+pub fn (mut p Process) signal_continue() {
+	if p.status != .stopped {
+		return
+	}
+	p._signal_continue()
+	p.status = .running
+	return
+}
+
+// wait - wait for a process to finish.
+// NB: You have to call p.wait(), otherwise a finished process
+// would get to a zombie state, and its resources will not get
+// released fully, until its parent process exits.
+// NB: This call will block the calling process until the child
+// process is finished.
+pub fn (mut p Process) wait() {
+	if p.status == .not_started {
+		p._spawn()
+	}
+	if p.status !in [.running, .stopped] {
+		return
+	}
+	p._wait()
+	return
+}
+
+// close - free the OS resources associated with the process.
+// Can be called multiple times, but will free the resources just once.
+// This sets the process state to .closed, which is final.
+pub fn (mut p Process) close() {
+	if p.status in [.not_started, .closed] {
+		return
+	}
+	p.status = .closed
+	$if !windows {
+		for i in 0 .. 3 {
+			if p.stdio_fd[i] != 0 {
+				fd_close(p.stdio_fd[i])
+			}
+		}
+	}
+}
+
+[unsafe]
+pub fn (mut p Process) free() {
+	p.close()
+	unsafe {
+		p.filename.free()
+		p.err.free()
+		p.args.free()
+		p.env.free()
+	}
+}
+
+//
+// _spawn - should not be called directly, but only by p.run()/p.wait() .
+// It encapsulates the fork/execve mechanism that allows the
+// asynchronous starting of the new child process.
+fn (mut p Process) _spawn() int {
+	if !p.env_is_custom {
+		p.env = []string{}
+		current_environment := environ()
+		for k, v in current_environment {
+			p.env << '$k=$v'
+		}
+	}
+	mut pid := 0
+	$if windows {
+		pid = p.win_spawn_process()
+	} $else {
+		pid = p.unix_spawn_process()
+	}
+	p.pid = pid
+	p.status = .running
+	return 0
+}
+
+// is_alive - query whether the process p.pid is still alive
+pub fn (mut p Process) is_alive() bool {
+	if p.status in [.running, .stopped] {
+		return p._is_alive()
+	}
+	return false
+}
+
+//
+pub fn (mut p Process) set_redirect_stdio() {
+	p.use_stdio_ctl = true
+	return
+}
+
+pub fn (mut p Process) stdin_write(s string) {
+	p._check_redirection_call('stdin_write')
+	$if windows {
+		p.win_write_string(0, s)
+	} $else {
+		fd_write(p.stdio_fd[0], s)
+	}
+}
+
+// will read from stdout pipe, will only return when EOF (end of file) or data
+// means this will block unless there is data
+pub fn (mut p Process) stdout_slurp() string {
+	p._check_redirection_call('stdout_slurp')
+	$if windows {
+		return p.win_slurp(1)
+	} $else {
+		return fd_slurp(p.stdio_fd[1]).join('')
+	}
+}
+
+// read from stderr pipe, wait for data or EOF
+pub fn (mut p Process) stderr_slurp() string {
+	p._check_redirection_call('stderr_slurp')
+	$if windows {
+		return p.win_slurp(2)
+	} $else {
+		return fd_slurp(p.stdio_fd[2]).join('')
+	}
+}
+
+// read from stdout, return if data or not
+pub fn (mut p Process) stdout_read() string {
+	p._check_redirection_call('stdout_read')
+	$if windows {
+		s, _ := p.win_read_string(1, 4096)
+		return s
+	} $else {
+		s, _ := fd_read(p.stdio_fd[1], 4096)
+		return s
+	}
+}
+
+pub fn (mut p Process) stderr_read() string {
+	p._check_redirection_call('stderr_read')
+	$if windows {
+		s, _ := p.win_read_string(2, 4096)
+		return s
+	} $else {
+		s, _ := fd_read(p.stdio_fd[2], 4096)
+		return s
+	}
+}
+
+// _check_redirection_call - should be called just by stdxxx methods
+fn (mut p Process) _check_redirection_call(fn_name string) {
+	if !p.use_stdio_ctl {
+		panic('Call p.set_redirect_stdio() before calling p.$fn_name')
+	}
+	if p.status == .not_started {
+		panic('Call p.${fn_name}() after you have called p.run()')
+	}
+}
+
+// _signal_stop - should not be called directly, except by p.signal_stop
+fn (mut p Process) _signal_stop() {
+	$if windows {
+		p.win_stop_process()
+	} $else {
+		p.unix_stop_process()
+	}
+}
+
+// _signal_continue - should not be called directly, just by p.signal_continue
+fn (mut p Process) _signal_continue() {
+	$if windows {
+		p.win_resume_process()
+	} $else {
+		p.unix_resume_process()
+	}
+}
+
+// _signal_kill - should not be called directly, except by p.signal_kill
+fn (mut p Process) _signal_kill() {
+	$if windows {
+		p.win_kill_process()
+	} $else {
+		p.unix_kill_process()
+	}
+}
+
+// _signal_pgkill - should not be called directly, except by p.signal_pgkill
+fn (mut p Process) _signal_pgkill() {
+	$if windows {
+		p.win_kill_pgroup()
+	} $else {
+		p.unix_kill_pgroup()
+	}
+}
+
+// _wait - should not be called directly, except by p.wait()
+fn (mut p Process) _wait() {
+	$if windows {
+		p.win_wait()
+	} $else {
+		p.unix_wait()
+	}
+}
+
+// _is_alive - should not be called directly, except by p.is_alive()
+fn (mut p Process) _is_alive() bool {
+	$if windows {
+		return p.win_is_alive()
+	} $else {
+		return p.unix_is_alive()
+	}
+}
+
+// run - starts the new process
+pub fn (mut p Process) run() {
+	if p.status != .not_started {
+		return
+	}
+	p._spawn()
+	return
+}

vlib/os/process.js.v

@@ -0,0 +1,117 @@
+module os
+
+#const $child_process = require('child_process')
+
+// new_process - create a new process descriptor
+// NB: new does NOT start the new process.
+// That is done because you may want to customize it first,
+// by calling different set_ methods on it.
+// In order to start it, call p.run() or p.wait()
+pub fn new_process(filename string) &Process {
+	return &Process{
+		filename: filename
+		stdio_fd: [-1, -1, -1]!
+	}
+}
+
+fn (mut p Process) spawn_internal() {
+	#p.val.pid = $child_process.spawn(
+	#p.val.filename+'',
+	#p.val.args.arr.map((x) => x.valueOf() + ''),
+	#{
+	#env: (p.val.env_is_custom ? p.val.env : $process.env),
+	#})
+	#p.val.pid.on('error', function (err) { builtin.panic('Failed to start subprocess') })
+
+	p.status = .running
+	// todo(playX): stderr,stdin
+	if p.use_stdio_ctl {
+		#p.val.pid.stdout.pipe(process.stdout)
+		#p.val.pid.stdin.pipe(process.stdin)
+		#p.val.pid.stderr.pipe(process.stderr)
+	}
+}
+
+pub fn (mut p Process) run() {
+	if p.status != .not_started {
+		return
+	}
+	p.spawn_internal()
+	return
+}
+
+pub fn (mut p Process) signal_kill() {
+	if p.status !in [.running, .stopped] {
+		return
+	}
+	#p.val.pid.kill('SIGKILL');
+
+	p.status = .aborted
+}
+
+pub fn (mut p Process) signal_stop() {
+	if p.status !in [.running, .stopped] {
+		return
+	}
+	#p.val.pid.kill('SIGSTOP');
+
+	p.status = .aborted
+}
+
+pub fn (mut p Process) signal_continue() {
+	if p.status != .stopped {
+		return
+	}
+	#p.val.pid.kill('SIGCONT');
+
+	p.status = .running
+	return
+}
+
+pub fn (mut p Process) wait() {
+	if p.status == .not_started {
+		p.spawn_internal()
+	}
+	if p.status !in [.running, .stopped] {
+		return
+	}
+
+	p.wait_internal()
+	return
+}
+
+fn (mut p Process) wait_internal() {
+	#p.val.pid.on('exit', function (code) { console.log(code) })
+}
+
+pub fn (mut p Process) set_redirect_stdio() {
+	p.use_stdio_ctl = true
+	return
+}
+
+pub fn (mut p Process) stdin_write(s string) {
+	p.check_redirection_call('stdin_write')
+	#p.val.pid.stdin.write(s)
+}
+
+// todo(playX): probably does not work
+
+// will read from stdout pipe, will only return when EOF (end of file) or data
+// means this will block unless there is data
+pub fn (mut p Process) stdout_slurp() string {
+	p.check_redirection_call('stdout_slurp')
+	mut res := ''
+	#p.val.pid.stdout.on('data', function (data) { res = new builtin.string(data) })
+
+	return res
+}
+
+// _check_redirection_call - should be called just by stdxxx methods
+fn (mut p Process) check_redirection_call(fn_name string) {
+	if !p.use_stdio_ctl {
+		panic('Call p.set_redirect_stdio() before calling p.$fn_name')
+	}
+	if p.status == .not_started {
+		panic('Call p.${fn_name}() after you have called p.run()')
+	}
+}

vlib/os/process.v

@@ -68,250 +68,3 @@ pub fn (mut p Process) set_environment(envs map[string]string) {
 	}
 	return
 }
-
-// run - starts the new process
-pub fn (mut p Process) run() {
-	if p.status != .not_started {
-		return
-	}
-	p._spawn()
-	return
-}
-
-// signal_kill - kills the process, after that it is no longer running
-pub fn (mut p Process) signal_kill() {
-	if p.status !in [.running, .stopped] {
-		return
-	}
-	p._signal_kill()
-	p.status = .aborted
-	return
-}
-
-// signal_pgkill - kills the whole process group
-pub fn (mut p Process) signal_pgkill() {
-	if p.status !in [.running, .stopped] {
-		return
-	}
-	p._signal_pgkill()
-	return
-}
-
-// signal_stop - stops the process, you can resume it with p.signal_continue()
-pub fn (mut p Process) signal_stop() {
-	if p.status != .running {
-		return
-	}
-	p._signal_stop()
-	p.status = .stopped
-	return
-}
-
-// signal_continue - tell a stopped process to continue/resume its work
-pub fn (mut p Process) signal_continue() {
-	if p.status != .stopped {
-		return
-	}
-	p._signal_continue()
-	p.status = .running
-	return
-}
-
-// wait - wait for a process to finish.
-// NB: You have to call p.wait(), otherwise a finished process
-// would get to a zombie state, and its resources will not get
-// released fully, until its parent process exits.
-// NB: This call will block the calling process until the child
-// process is finished.
-pub fn (mut p Process) wait() {
-	if p.status == .not_started {
-		p._spawn()
-	}
-	if p.status !in [.running, .stopped] {
-		return
-	}
-	p._wait()
-	return
-}
-
-// close - free the OS resources associated with the process.
-// Can be called multiple times, but will free the resources just once.
-// This sets the process state to .closed, which is final.
-pub fn (mut p Process) close() {
-	if p.status in [.not_started, .closed] {
-		return
-	}
-	p.status = .closed
-	$if !windows {
-		for i in 0 .. 3 {
-			if p.stdio_fd[i] != 0 {
-				fd_close(p.stdio_fd[i])
-			}
-		}
-	}
-}
-
-[unsafe]
-pub fn (mut p Process) free() {
-	p.close()
-	unsafe {
-		p.filename.free()
-		p.err.free()
-		p.args.free()
-		p.env.free()
-	}
-}
-
-//
-// _spawn - should not be called directly, but only by p.run()/p.wait() .
-// It encapsulates the fork/execve mechanism that allows the
-// asynchronous starting of the new child process.
-fn (mut p Process) _spawn() int {
-	if !p.env_is_custom {
-		p.env = []string{}
-		current_environment := environ()
-		for k, v in current_environment {
-			p.env << '$k=$v'
-		}
-	}
-	mut pid := 0
-	$if windows {
-		pid = p.win_spawn_process()
-	} $else {
-		pid = p.unix_spawn_process()
-	}
-	p.pid = pid
-	p.status = .running
-	return 0
-}
-
-// is_alive - query whether the process p.pid is still alive
-pub fn (mut p Process) is_alive() bool {
-	if p.status in [.running, .stopped] {
-		return p._is_alive()
-	}
-	return false
-}
-
-//
-pub fn (mut p Process) set_redirect_stdio() {
-	p.use_stdio_ctl = true
-	return
-}
-
-pub fn (mut p Process) stdin_write(s string) {
-	p._check_redirection_call('stdin_write')
-	$if windows {
-		p.win_write_string(0, s)
-	} $else {
-		fd_write(p.stdio_fd[0], s)
-	}
-}
-
-// will read from stdout pipe, will only return when EOF (end of file) or data
-// means this will block unless there is data
-pub fn (mut p Process) stdout_slurp() string {
-	p._check_redirection_call('stdout_slurp')
-	$if windows {
-		return p.win_slurp(1)
-	} $else {
-		return fd_slurp(p.stdio_fd[1]).join('')
-	}
-}
-
-// read from stderr pipe, wait for data or EOF
-pub fn (mut p Process) stderr_slurp() string {
-	p._check_redirection_call('stderr_slurp')
-	$if windows {
-		return p.win_slurp(2)
-	} $else {
-		return fd_slurp(p.stdio_fd[2]).join('')
-	}
-}
-
-// read from stdout, return if data or not
-pub fn (mut p Process) stdout_read() string {
-	p._check_redirection_call('stdout_read')
-	$if windows {
-		s, _ := p.win_read_string(1, 4096)
-		return s
-	} $else {
-		s, _ := fd_read(p.stdio_fd[1], 4096)
-		return s
-	}
-}
-
-pub fn (mut p Process) stderr_read() string {
-	p._check_redirection_call('stderr_read')
-	$if windows {
-		s, _ := p.win_read_string(2, 4096)
-		return s
-	} $else {
-		s, _ := fd_read(p.stdio_fd[2], 4096)
-		return s
-	}
-}
-
-// _check_redirection_call - should be called just by stdxxx methods
-fn (mut p Process) _check_redirection_call(fn_name string) {
-	if !p.use_stdio_ctl {
-		panic('Call p.set_redirect_stdio() before calling p.$fn_name')
-	}
-	if p.status == .not_started {
-		panic('Call p.${fn_name}() after you have called p.run()')
-	}
-}
-
-// _signal_stop - should not be called directly, except by p.signal_stop
-fn (mut p Process) _signal_stop() {
-	$if windows {
-		p.win_stop_process()
-	} $else {
-		p.unix_stop_process()
-	}
-}
-
-// _signal_continue - should not be called directly, just by p.signal_continue
-fn (mut p Process) _signal_continue() {
-	$if windows {
-		p.win_resume_process()
-	} $else {
-		p.unix_resume_process()
-	}
-}
-
-// _signal_kill - should not be called directly, except by p.signal_kill
-fn (mut p Process) _signal_kill() {
-	$if windows {
-		p.win_kill_process()
-	} $else {
-		p.unix_kill_process()
-	}
-}
-
-// _signal_pgkill - should not be called directly, except by p.signal_pgkill
-fn (mut p Process) _signal_pgkill() {
-	$if windows {
-		p.win_kill_pgroup()
-	} $else {
-		p.unix_kill_pgroup()
-	}
-}
-
-// _wait - should not be called directly, except by p.wait()
-fn (mut p Process) _wait() {
-	$if windows {
-		p.win_wait()
-	} $else {
-		p.unix_wait()
-	}
-}
-
-// _is_alive - should not be called directly, except by p.is_alive()
-fn (mut p Process) _is_alive() bool {
-	$if windows {
-		return p.win_is_alive()
-	} $else {
-		return p.unix_is_alive()
-	}
-}

vlib/v/gen/js/builtin_types.v

@@ -348,7 +348,7 @@ fn (mut g JsGen) gen_builtin_type_defs() {
 			'f32', 'f64', 'float_literal' {
 				g.gen_builtin_prototype(
 					typ_name: typ_name
-					constructor: 'this.val = +val'
+					constructor: 'this.val = Number(val)'
 					default_value: 'new Number(0)'
 					to_jsval: '+this'
 				)

vlib/v/gen/js/js.v

@@ -1595,6 +1595,7 @@ fn (mut g JsGen) gen_method_call(it ast.CallExpr) bool {
 			}
 		}
 	}
+
 	// interfaces require dynamic dispatch. To obtain method table we use getPrototypeOf
 	g.write('Object.getPrototypeOf(')
 	g.expr(it.left)
@@ -1660,6 +1661,15 @@ fn (mut g JsGen) gen_call_expr(it ast.CallExpr) {
 	}
 	g.call_stack << it
 	mut name := g.js_name(it.name)
+	ret_sym := g.table.get_type_symbol(it.return_type)
+	if it.language == .js && ret_sym.name in js.v_types && ret_sym.name != 'void' {
+		g.write('new ')
+		if g.ns.name != 'builtin' {
+			g.write('builtin.')
+		}
+		g.write(ret_sym.name)
+		g.write('(')
+	}
 	call_return_is_optional := it.return_type.has_flag(.optional)
 	if call_return_is_optional {
 		g.writeln('(function(){')
@@ -1717,6 +1727,9 @@ fn (mut g JsGen) gen_call_expr(it ast.CallExpr) {
 		g.dec_indent()
 		g.write('})()')
 	}
+	if it.language == .js && ret_sym.name in js.v_types && ret_sym.name != 'void' {
+		g.write(')')
+	}
 	g.call_stack.delete_last()
 }
 
@@ -1761,7 +1774,7 @@ fn (mut g JsGen) need_tmp_var_in_match(node ast.MatchExpr) bool {
 	return false
 }
 
-fn (mut g JsGen) match_expr_classic(node ast.MatchExpr, is_expr bool, cond_var string, tmp_var string) {
+fn (mut g JsGen) match_expr_classic(node ast.MatchExpr, is_expr bool, cond_var MatchCond, tmp_var string) {
 	type_sym := g.table.get_type_symbol(node.cond_type)
 	for j, branch in node.branches {
 		is_last := j == node.branches.len - 1
@@ -1801,27 +1814,37 @@ fn (mut g JsGen) match_expr_classic(node ast.MatchExpr, is_expr bool, cond_var s
 				}
 				match type_sym.kind {
 					.array {
-						g.write('vEq($cond_var, ')
+						g.write('vEq(')
+						g.match_cond(cond_var)
+						g.write(',')
 						g.expr(expr)
 						g.write(')')
 					}
 					.array_fixed {
-						g.write('vEq($cond_var, ')
+						g.write('vEq(')
+						g.match_cond(cond_var)
+						g.write(',')
 						g.expr(expr)
 						g.write(')')
 					}
 					.map {
-						g.write('vEq($cond_var, ')
+						g.write('vEq(')
+						g.match_cond(cond_var)
+						g.write(',')
 						g.expr(expr)
 						g.write(')')
 					}
 					.string {
-						g.write('vEq($cond_var, ')
+						g.write('vEq(')
+						g.match_cond(cond_var)
+						g.write(',')
 						g.expr(expr)
 						g.write(')')
 					}
 					.struct_ {
-						g.write('vEq($cond_var, ')
+						g.write('vEq(')
+						g.match_cond(cond_var)
+						g.write(',')
 						g.expr(expr)
 						g.write(')')
 					}
@@ -1837,15 +1860,19 @@ fn (mut g JsGen) match_expr_classic(node ast.MatchExpr, is_expr bool, cond_var s
 							}
 							g.write('(')
 							if !skip_low {
-								g.write('$cond_var >= ')
+								g.match_cond(cond_var)
+								g.write(' >= ')
 								g.expr(expr.low)
 								g.write(' && ')
 							}
-							g.write('$cond_var <= ')
+							g.match_cond(cond_var)
+							g.write(' <= ')
 							g.expr(expr.high)
 							g.write(')')
 						} else {
-							g.write('vEq($cond_var,')
+							g.write('vEq(')
+							g.match_cond(cond_var)
+							g.write(',')
 							g.expr(expr)
 							g.write(')')
 						}
@@ -1865,6 +1892,27 @@ fn (mut g JsGen) match_expr_classic(node ast.MatchExpr, is_expr bool, cond_var s
 	}
 }
 
+type MatchCond = CondExpr | CondString
+
+struct CondString {
+	s string
+}
+
+struct CondExpr {
+	expr ast.Expr
+}
+
+fn (mut g JsGen) match_cond(cond MatchCond) {
+	match cond {
+		CondString {
+			g.writeln(cond.s)
+		}
+		CondExpr {
+			g.expr(cond.expr)
+		}
+	}
+}
+
 fn (mut g JsGen) match_expr(node ast.MatchExpr) {
 	if node.cond_type == 0 {
 		g.writeln('// match 0')
@@ -1873,16 +1921,22 @@ fn (mut g JsGen) match_expr(node ast.MatchExpr) {
 	prev := g.inside_ternary
 	need_tmp_var := g.need_tmp_var_in_match(node)
 	is_expr := (node.is_expr && node.return_type != ast.void_type) || g.inside_ternary
-	mut cond_var := ''
+	mut cond_var := MatchCond(CondString{''})
 	mut tmp_var := ''
 	if is_expr && !need_tmp_var {
 		g.inside_ternary = true
 	}
 
-	cond_var = g.new_tmp_var()
+	if node.cond is ast.Ident || node.cond is ast.SelectorExpr || node.cond is ast.IntegerLiteral
-	g.write('let $cond_var = ')
+		|| node.cond is ast.StringLiteral || node.cond is ast.FloatLiteral {
-	g.expr(node.cond)
+		cond_var = CondExpr{node.cond}
-	g.write(';')
+	} else {
+		s := g.new_tmp_var()
+		cond_var = CondString{s}
+		g.write('let $s = ')
+		g.expr(node.cond)
+		g.writeln(';')
+	}
 	if need_tmp_var {
 		tmp_var = g.new_tmp_var()
 		g.writeln('let $tmp_var = undefined;')
@@ -1927,7 +1981,7 @@ fn (mut g JsGen) stmts_with_tmp_var(stmts []ast.Stmt, tmp_var string) {
 	}
 }
 
-fn (mut g JsGen) match_expr_sumtype(node ast.MatchExpr, is_expr bool, cond_var string, tmp_var string) {
+fn (mut g JsGen) match_expr_sumtype(node ast.MatchExpr, is_expr bool, cond_var MatchCond, tmp_var string) {
 	for j, branch in node.branches {
 		mut sumtype_index := 0
 		for {
@@ -1954,7 +2008,7 @@ fn (mut g JsGen) match_expr_sumtype(node ast.MatchExpr, is_expr bool, cond_var s
 				} else {
 					g.write('if (')
 				}
-				g.write(cond_var)
+				g.match_cond(cond_var)
 				if sym.kind == .sum_type {
 					g.write(' instanceof ')
 					g.expr(branch.exprs[sumtype_index])
@@ -2669,20 +2723,20 @@ fn (mut g JsGen) gen_float_literal_expr(it ast.FloatLiteral) {
 	// TODO: call.language always seems to be "v", parser bug?
 	if g.call_stack.len > 0 {
 		call := g.call_stack[g.call_stack.len - 1]
-		// if call.language == .js {
+		if call.language == .js {
-		for i, t in call.args {
+			for i, t in call.args {
-			if t.expr is ast.FloatLiteral {
+				if t.expr is ast.FloatLiteral {
-				if t.expr == it {
+					if t.expr == it {
-					if call.expected_arg_types[i] in ast.integer_type_idxs {
+						if call.expected_arg_types[i] in ast.integer_type_idxs {
-						g.write(int(it.val.f64()).str())
+							g.write(int(it.val.f64()).str())
-					} else {
+						} else {
-						g.write(it.val)
+							g.write(it.val)
+						}
+						return
 					}
-					return
 				}
 			}
 		}
-		//}
 	}
 
 	// Skip cast if type is the same as the parrent caster