gow_misc.go

package main

import (
	"io"
	"os"
	"path/filepath"
	"regexp"
	"strings"
	"syscall"

	"github.com/mitranim/gg"
)

const (
	// These names reflect standard naming and meaning.
	// Reference: https://en.wikipedia.org/wiki/Ascii.
	// See our re-interpretation below.
	ASCII_END_OF_TEXT      = 3   // ^C
	ASCII_BACKSPACE        = 8   // ^H
	ASCII_FILE_SEPARATOR   = 28  // ^\
	ASCII_DEVICE_CONTROL_2 = 18  // ^R
	ASCII_DEVICE_CONTROL_4 = 20  // ^T
	ASCII_UNIT_SEPARATOR   = 31  // ^- or ^?
	ASCII_DELETE           = 127 // ^H on MacOS

	// These names reflect our re-interpretation of standard codes.
	CODE_INTERRUPT        = ASCII_END_OF_TEXT
	CODE_QUIT             = ASCII_FILE_SEPARATOR
	CODE_RESTART          = ASCII_DEVICE_CONTROL_2
	CODE_STOP             = ASCII_DEVICE_CONTROL_4
	CODE_PRINT_COMMAND    = ASCII_UNIT_SEPARATOR
	CODE_PRINT_HELP       = ASCII_BACKSPACE
	CODE_PRINT_HELP_MACOS = ASCII_DELETE
)

const HOTKEY_HELP = `Control codes / hotkeys:

	3     ^C          Kill subprocess with SIGINT. Repeat within 1s to kill gow.
	18    ^R          Kill subprocess with SIGTERM, restart.
	20    ^T          Kill subprocess with SIGTERM. Repeat within 1s to kill gow.
	28    ^\          Kill subprocess with SIGQUIT. Repeat within 1s to kill gow.
	31    ^- or ^?    Print currently running command.
	8     ^H	  Print this help.
	127   ^H (MacOS)  Print this help.`

var (
	FD_TERM      = syscall.Stdin
	KILL_SIGS    = []syscall.Signal{syscall.SIGHUP, syscall.SIGINT, syscall.SIGQUIT, syscall.SIGTERM}
	KILL_SIGS_OS = gg.Map(KILL_SIGS, toOsSignal[syscall.Signal])
	KILL_SIG_SET = gg.SetOf(KILL_SIGS...)
	RE_WORD      = regexp.MustCompile(`^\w+$`)
	PATH_SEP     = string([]rune{os.PathSeparator})

	REP_SINGLE_MULTI = strings.NewReplacer(
		`\r\n`, gg.Newline,
		`\r`, gg.Newline,
		`\n`, gg.Newline,
	)
)

/*
Making `.main` private reduces the chance of accidental cyclic walking by
reflection tools such as pretty printers.
*/
type Mained struct{ main *Main }

func (self *Mained) Init(val *Main) { self.main = val }
func (self *Mained) Main() *Main    { return self.main }

/*
Implemented by `notify.EventInfo`.
Path must be an absolute filesystem path.
*/
type FsEvent interface{ Path() string }

// Implemented by `WatchNotify`.
type Watcher interface {
	Init(*Main)
	Deinit()
	Run()
}

func commaSplit(val string) []string {
	if len(val) <= 0 {
		return nil
	}
	return strings.Split(val, `,`)
}

func cleanExtension(val string) string {
	ext := filepath.Ext(val)
	if len(ext) > 0 && ext[0] == '.' {
		return ext[1:]
	}
	return ext
}

func validateExtension(val string) {
	if !RE_WORD.MatchString(val) {
		panic(gg.Errf(`invalid extension %q`, val))
	}
}

func toAbsPath(val string) string {
	if !filepath.IsAbs(val) {
		val = filepath.Join(cwd, val)
	}
	return filepath.Clean(val)
}

func toDirPath(val string) string {
	if val == `` || strings.HasSuffix(val, PATH_SEP) {
		return val
	}
	return val + PATH_SEP
}

func toAbsDirPath(val string) string { return toDirPath(toAbsPath(val)) }

func toOsSignal[A os.Signal](src A) os.Signal { return src }

func recLog() {
	val := recover()
	if val != nil {
		log.Println(val)
	}
}

func withNewline[A ~string](val A) A {
	if gg.HasNewlineSuffix(val) {
		return val
	}
	return val + A(gg.Newline)
}

func writeByte[A io.Writer](tar A, char byte) (int, error) {
	buf := [1]byte{char}
	return tar.Write(gg.NoEscUnsafe(&buf)[:])
}