1
0
mirror of https://github.com/jesseduffield/lazygit.git synced 2024-12-12 11:15:00 +02:00
lazygit/vendor/github.com/xo/terminfo/param.go

491 lines
7.8 KiB
Go

package terminfo
import (
"bytes"
"fmt"
"io"
"strconv"
"strings"
"sync"
)
// parametizer represents the a scan state for a parameterized string.
type parametizer struct {
// z is the string to parameterize
z []byte
// pos is the current position in s.
pos int
// nest is the current nest level.
nest int
// s is the variable stack.
s stack
// skipElse keeps the state of skipping else.
skipElse bool
// buf is the result buffer.
buf *bytes.Buffer
// params are the parameters to interpolate.
params [9]interface{}
// vars are dynamic variables.
vars [26]interface{}
}
// staticVars are the static, global variables.
var staticVars = struct {
vars [26]interface{}
sync.Mutex
}{}
var parametizerPool = sync.Pool{
New: func() interface{} {
p := new(parametizer)
p.buf = bytes.NewBuffer(make([]byte, 0, 45))
return p
},
}
// newParametizer returns a new initialized parametizer from the pool.
func newParametizer(z []byte) *parametizer {
p := parametizerPool.Get().(*parametizer)
p.z = z
return p
}
// reset resets the parametizer.
func (p *parametizer) reset() {
p.pos, p.nest = 0, 0
p.s.reset()
p.buf.Reset()
p.params, p.vars = [9]interface{}{}, [26]interface{}{}
parametizerPool.Put(p)
}
// stateFn represents the state of the scanner as a function that returns the
// next state.
type stateFn func() stateFn
// exec executes the parameterizer, interpolating the supplied parameters.
func (p *parametizer) exec() string {
for state := p.scanTextFn; state != nil; {
state = state()
}
return p.buf.String()
}
// peek returns the next byte.
func (p *parametizer) peek() (byte, error) {
if p.pos >= len(p.z) {
return 0, io.EOF
}
return p.z[p.pos], nil
}
// writeFrom writes the characters from ppos to pos to the buffer.
func (p *parametizer) writeFrom(ppos int) {
if p.pos > ppos {
// append remaining characters.
p.buf.Write(p.z[ppos:p.pos])
}
}
func (p *parametizer) scanTextFn() stateFn {
ppos := p.pos
for {
ch, err := p.peek()
if err != nil {
p.writeFrom(ppos)
return nil
}
if ch == '%' {
p.writeFrom(ppos)
p.pos++
return p.scanCodeFn
}
p.pos++
}
}
func (p *parametizer) scanCodeFn() stateFn {
ch, err := p.peek()
if err != nil {
return nil
}
switch ch {
case '%':
p.buf.WriteByte('%')
case ':':
// this character is used to avoid interpreting "%-" and "%+" as operators.
// the next character is where the format really begins.
p.pos++
_, err = p.peek()
if err != nil {
return nil
}
return p.scanFormatFn
case '#', ' ', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '.':
return p.scanFormatFn
case 'o':
p.buf.WriteString(strconv.FormatInt(int64(p.s.popInt()), 8))
case 'd':
p.buf.WriteString(strconv.Itoa(p.s.popInt()))
case 'x':
p.buf.WriteString(strconv.FormatInt(int64(p.s.popInt()), 16))
case 'X':
p.buf.WriteString(strings.ToUpper(strconv.FormatInt(int64(p.s.popInt()), 16)))
case 's':
p.buf.WriteString(p.s.popString())
case 'c':
p.buf.WriteByte(p.s.popByte())
case 'p':
p.pos++
return p.pushParamFn
case 'P':
p.pos++
return p.setDsVarFn
case 'g':
p.pos++
return p.getDsVarFn
case '\'':
p.pos++
ch, err = p.peek()
if err != nil {
return nil
}
p.s.push(ch)
// skip the '\''
p.pos++
case '{':
p.pos++
return p.pushIntfn
case 'l':
p.s.push(len(p.s.popString()))
case '+':
bi, ai := p.s.popInt(), p.s.popInt()
p.s.push(ai + bi)
case '-':
bi, ai := p.s.popInt(), p.s.popInt()
p.s.push(ai - bi)
case '*':
bi, ai := p.s.popInt(), p.s.popInt()
p.s.push(ai * bi)
case '/':
bi, ai := p.s.popInt(), p.s.popInt()
if bi != 0 {
p.s.push(ai / bi)
} else {
p.s.push(0)
}
case 'm':
bi, ai := p.s.popInt(), p.s.popInt()
if bi != 0 {
p.s.push(ai % bi)
} else {
p.s.push(0)
}
case '&':
bi, ai := p.s.popInt(), p.s.popInt()
p.s.push(ai & bi)
case '|':
bi, ai := p.s.popInt(), p.s.popInt()
p.s.push(ai | bi)
case '^':
bi, ai := p.s.popInt(), p.s.popInt()
p.s.push(ai ^ bi)
case '=':
bi, ai := p.s.popInt(), p.s.popInt()
p.s.push(ai == bi)
case '>':
bi, ai := p.s.popInt(), p.s.popInt()
p.s.push(ai > bi)
case '<':
bi, ai := p.s.popInt(), p.s.popInt()
p.s.push(ai < bi)
case 'A':
bi, ai := p.s.popBool(), p.s.popBool()
p.s.push(ai && bi)
case 'O':
bi, ai := p.s.popBool(), p.s.popBool()
p.s.push(ai || bi)
case '!':
p.s.push(!p.s.popBool())
case '~':
p.s.push(^p.s.popInt())
case 'i':
for i := range p.params[:2] {
if n, ok := p.params[i].(int); ok {
p.params[i] = n + 1
}
}
case '?', ';':
case 't':
return p.scanThenFn
case 'e':
p.skipElse = true
return p.skipTextFn
}
p.pos++
return p.scanTextFn
}
func (p *parametizer) scanFormatFn() stateFn {
// the character was already read, so no need to check the error.
ch, _ := p.peek()
// 6 should be the maximum length of a format string, for example "%:-9.9d".
f := []byte{'%', ch, 0, 0, 0, 0}
var err error
for {
p.pos++
ch, err = p.peek()
if err != nil {
return nil
}
f = append(f, ch)
switch ch {
case 'o', 'd', 'x', 'X':
fmt.Fprintf(p.buf, string(f), p.s.popInt())
break
case 's':
fmt.Fprintf(p.buf, string(f), p.s.popString())
break
case 'c':
fmt.Fprintf(p.buf, string(f), p.s.popByte())
break
}
}
p.pos++
return p.scanTextFn
}
func (p *parametizer) pushParamFn() stateFn {
ch, err := p.peek()
if err != nil {
return nil
}
if ai := int(ch - '1'); ai >= 0 && ai < len(p.params) {
p.s.push(p.params[ai])
} else {
p.s.push(0)
}
// skip the '}'
p.pos++
return p.scanTextFn
}
func (p *parametizer) setDsVarFn() stateFn {
ch, err := p.peek()
if err != nil {
return nil
}
if ch >= 'A' && ch <= 'Z' {
staticVars.Lock()
staticVars.vars[int(ch-'A')] = p.s.pop()
staticVars.Unlock()
} else if ch >= 'a' && ch <= 'z' {
p.vars[int(ch-'a')] = p.s.pop()
}
p.pos++
return p.scanTextFn
}
func (p *parametizer) getDsVarFn() stateFn {
ch, err := p.peek()
if err != nil {
return nil
}
var a byte
if ch >= 'A' && ch <= 'Z' {
a = 'A'
} else if ch >= 'a' && ch <= 'z' {
a = 'a'
}
staticVars.Lock()
p.s.push(staticVars.vars[int(ch-a)])
staticVars.Unlock()
p.pos++
return p.scanTextFn
}
func (p *parametizer) pushIntfn() stateFn {
var ai int
for {
ch, err := p.peek()
if err != nil {
return nil
}
p.pos++
if ch < '0' || ch > '9' {
p.s.push(ai)
return p.scanTextFn
}
ai = (ai * 10) + int(ch-'0')
}
}
func (p *parametizer) scanThenFn() stateFn {
p.pos++
if p.s.popBool() {
return p.scanTextFn
}
p.skipElse = false
return p.skipTextFn
}
func (p *parametizer) skipTextFn() stateFn {
for {
ch, err := p.peek()
if err != nil {
return nil
}
p.pos++
if ch == '%' {
break
}
}
if p.skipElse {
return p.skipElseFn
}
return p.skipThenFn
}
func (p *parametizer) skipThenFn() stateFn {
ch, err := p.peek()
if err != nil {
return nil
}
p.pos++
switch ch {
case ';':
if p.nest == 0 {
return p.scanTextFn
}
p.nest--
case '?':
p.nest++
case 'e':
if p.nest == 0 {
return p.scanTextFn
}
}
return p.skipTextFn
}
func (p *parametizer) skipElseFn() stateFn {
ch, err := p.peek()
if err != nil {
return nil
}
p.pos++
switch ch {
case ';':
if p.nest == 0 {
return p.scanTextFn
}
p.nest--
case '?':
p.nest++
}
return p.skipTextFn
}
// Printf evaluates a parameterized terminfo value z, interpolating params.
func Printf(z []byte, params ...interface{}) string {
p := newParametizer(z)
defer p.reset()
// make sure we always have 9 parameters -- makes it easier
// later to skip checks and its faster
for i := 0; i < len(p.params) && i < len(params); i++ {
p.params[i] = params[i]
}
return p.exec()
}
// Fprintf evaluates a parameterized terminfo value z, interpolating params and
// writing to w.
func Fprintf(w io.Writer, z []byte, params ...interface{}) {
w.Write([]byte(Printf(z, params...)))
}