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sloum 2021-05-23 22:21:25 -07:00
commit 8b537d30a4
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357
main.go Normal file
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package main
import (
"flag"
"fmt"
"io/ioutil"
"math"
"os"
"strconv"
"strings"
"tildegit.org/sloum/nums/qline"
"tildegit.org/sloum/nums/termios"
)
const (
add int = iota
sub
mul
div
pow
rnd
flr
cil
abs
inv
sqt
)
type stack struct {
ptr int
data [100]float64
}
func (s *stack) Push(v float64) {
if s.ptr >= 99 {
PrintError("Stack overflow")
s.Clear()
return
}
s.ptr++
s.data[s.ptr] = v
}
func (s *stack) Pop() (float64, error) {
if s.ptr < 0 {
PrintError("Stack underflow")
s.Clear()
return 0.0, fmt.Errorf("Stack underflow")
}
s.ptr--
return s.data[s.ptr+1], nil
}
func (s *stack) Clear() {
s.ptr = -1
}
func (s stack) Len() int {
return s.ptr+1
}
func (s *stack) Add() {
n2, err := s.Pop()
if err != nil {
return
}
n1, err := s.Pop()
if err != nil {
return
}
s.Push(n1+n2)
}
func (s *stack) Sub() {
n2, err := s.Pop()
if err != nil {
return
}
n1, err := s.Pop()
if err != nil {
return
}
s.Push(n1-n2)
}
func (s *stack) Mul() {
n2, err := s.Pop()
if err != nil {
return
}
n1, err := s.Pop()
if err != nil {
return
}
s.Push(n1*n2)
}
func (s *stack) Div() {
n2, err := s.Pop()
if err != nil {
return
}
n1, err := s.Pop()
if err != nil {
return
}
s.Push(n1/n2)
}
func (s *stack) Pow() {
exp, err := s.Pop()
if err != nil {
return
}
base, err := s.Pop()
if err != nil {
return
}
s.Push(math.Pow(base, exp))
}
func (s *stack) Floor() {
n, err := s.Pop()
if err != nil {
return
}
s.Push(math.Floor(n))
}
func (s *stack) Ceil() {
n, err := s.Pop()
if err != nil {
return
}
s.Push(math.Ceil(n))
}
func (s *stack) Round() {
decimals, err := s.Pop()
if err != nil {
return
}
num, err := s.Pop()
if err != nil {
return
}
s.Push(math.Round(num*math.Pow(10, decimals)) / math.Pow(10, decimals))
}
func (s *stack) Abs() {
n, err := s.Pop()
if err != nil {
return
}
if n < 0 {
s.Push(n*-1)
} else {
s.Push(n)
}
}
func (s *stack) Inv() {
n, err := s.Pop()
if err != nil {
return
}
s.Push(n*-1)
}
func (s *stack) Sqt() {
n, err := s.Pop()
if err != nil {
return
}
s.Push(math.Sqrt(n))
}
func (s *stack) Dup() {
val, err := s.Pop()
if err != nil {
return
}
s.Push(val)
s.Push(val)
}
func (s *stack) Ovr() {
tos, err := s.Pop()
if err != nil {
return
}
cpy, err := s.Pop()
if err != nil {
return
}
s.Push(cpy)
s.Push(tos)
s.Push(cpy)
}
func (s *stack) Swp() {
tos, err := s.Pop()
if err != nil {
return
}
newTos, err := s.Pop()
if err != nil {
return
}
s.Push(tos)
s.Push(newTos)
}
func (s *stack) Drp() {
s.Pop()
}
func (s stack) TOS() string {
if s.ptr < 0 {
return "0"
}
return strconv.FormatFloat(s.data[s.ptr], 'f', -1, 64)
}
func PrintError(s string) {
fmt.Fprintf(os.Stderr, "\033[1;91m[Err] %s,\033[0m\n", s)
}
func PrintOperatorHelp() {
txt := `# General
This calculator uses reverse polish notation. As such, the operators come after the operands. For example:
5 7 + 1 -
The output of the above would be '11' (using infix notation this would be written ' 5 + 7 - 1'). For more information on reverse polish notation see: https://en.wikipedia.org/wiki/Reverse_Polish_notation
The output of a calculation will always be the top of the stack. If there is more than one value on the stack at the end of a calculation a warning will be output to stderr.
# Command List
The following commands all have a three character version and a single character version. Either one is valid. They are displayed as a comma separated values (single character version first) followed by a colon and a description of the operator. The operators are case insensitive.
+, add: Adds the top two values on the stack
-, sub: Subtracts the top stack value from the value underneath it
/, div: Divides the top two stack values with the top of stack being the divisor and the value below it on the stack being the dividend
*, mul: Multiplies the top two values on the stack
^, pow: Raises the value underneath top of stack to the power of top of stack
@, rnd: Rounds the value underneath top of stack to the number of decimal places represented by top of stack. If top of stack is not a whole number an error will result
>, cil: Performs a ceiling function on the top of stack (rounds it up to the next whole number)
<, flr: Performs a floor function on the top of stack (rounds it down to the next whole number)
|, abs: Takes the top value from the stack and leaves its absolute value
!, inv: Multiplies top of stack by -1
V, sqt: Takes the top value from the stack and leaves its square root
The following commands operate on the stack, rather than as numerical operations:
x, swp: Swap the position of the top two values on the stack
#, dup: Duplicate/copy the value on top of the stack such that the copy is now above the original on the stack
_, clr: Clear the stack (wipe out all values and start over)
., drp: Drop the top value on the stack (remove it and throw it away)
?, help: Prints this help message
`
fmt.Fprintf(os.Stderr, "%s\033\n", txt)
}
func processWord(w string, s *stack) {
num, err := strconv.ParseFloat(w, 64)
if err == nil {
s.Push(num)
return
}
w = strings.ToLower(w)
switch w {
case "+", "add":
s.Add()
case "-", "sub":
s.Sub()
case "*", "mul":
s.Mul()
case "/", "div":
s.Div()
case "^", "pow":
s.Pow()
case "@", "rnd":
s.Round()
case ">", "cil":
s.Ceil()
case "<", "flr":
s.Floor()
case "|", "abs":
s.Abs()
case "!", "inv":
s.Inv()
case "V", "sqt":
s.Sqt()
case "#", "dup":
s.Dup()
case "x", "swp":
s.Swp()
case "_", "clr":
s.Clear()
case ".", "drp":
s.Drp()
case "?", "help":
PrintOperatorHelp()
s.Clear()
default:
PrintError(fmt.Sprintf("Unknown operator: %q", w))
s.Clear()
}
}
func main() {
pipe := flag.Bool("p", false, "Take input from a pipe")
flag.Parse()
s := stack{-1, [100]float64{}}
if !*pipe {
termios.SetInitialTermios()
defer termios.Restore()
termios.SetCharMode()
for {
var cols, _ = termios.GetWindowSize()
ln := qline.GetInput("", "", cols)
f := strings.Fields(ln)
if len(f) == 0 {
break
}
fmt.Print("\n")
for _, val := range f {
processWord(val, &s)
}
fmt.Fprintf(os.Stderr, "%v\n", s.data[:s.ptr+1])
}
} else {
b, err := ioutil.ReadAll(os.Stdin)
if err != nil {
fmt.Fprint(os.Stderr, "Unable to read from pipe")
}
f := strings.Fields(string(b))
for _, val := range f {
processWord(val, &s)
}
if s.ptr >= 0 {
fmt.Fprintf(os.Stderr, "%v\n", s.data[s.ptr])
} else {
os.Exit(1)
}
}
}

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284
qline/qline.go Normal file
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package qline
// qline is a line input library for terminals that utilize
// vt100 compatible escape sequences
//
// Copyright © 2021 Brian Evans
//
// Permission is hereby granted, free of charge, to any
// person obtaining a copy of this software and associated
// documentation files (the “Software”), to deal in the
// Software without restriction, including without
// limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of
// the Software, and to permit persons to whom the Software
// is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice
// shall be included in all copies or substantial portions
// of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
// KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
// PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
// CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
import (
"bufio"
"fmt"
"os"
"strings"
)
const (
UpArrow rune = iota - 20
DownArrow
LeftArrow
RightArrow
Delete
Home
End
PageUp
PageDown
Escape rune = 27
NewLine rune = 10
CarriageReturn rune = 13
BackSpace rune = 127
)
var (
width int
)
type buffer struct {
buf []rune
cursor int
maxWidth int
offset int
cursorStart int
prompt string
}
func GetInput(prompt string, content string, cols int) string {
b := buffer{make([]rune, 0, (len(content)+1)*2), 0, cols-len(prompt), 0, 0, prompt}
var ch rune
var err error
reader := bufio.NewReader(os.Stdin)
// b.seedContent(content)
// b.printBuf()
for {
ch, err = ReadKey(reader)
if err != nil {
continue
}
if ch == CarriageReturn || ch == NewLine {
break
}
if isControl(ch) {
b.controlInput(ch)
} else {
b.addChar(ch, true)
}
}
return b.string()
}
func (lb buffer) string() string {
return string(lb.buf)
}
func (lb *buffer) deleteChar() {
if lb.cursor == len(lb.buf) {
return
} else if lb.cursor == len(lb.buf)-1 {
lb.buf = lb.buf[:len(lb.buf)-1]
} else {
lb.buf = append(lb.buf[:lb.cursor], lb.buf[lb.cursor+1:]...)
}
if lb.offset > 0 {
lb.offset--
}
}
func (lb *buffer) addChar(c rune, echo bool) {
if c < 9 || (c > 10 && c < 13) || (c > 13 && c < 32) {
return
}
if lb.cursor == len(lb.buf) {
lb.buf = append(lb.buf, c)
lb.cursor++
} else {
lb.buf = append(lb.buf[:lb.cursor+1], lb.buf[lb.cursor:]...)
lb.buf[lb.cursor] = c
lb.cursor++
}
if lb.cursor - lb.offset > lb.maxWidth {
lb.offset++
}
if echo {
lb.printBuf()
}
}
func min(a, b int) int {
if a < b {
return a
}
return b
}
func max(a, b int) int {
if a > b {
return a
}
return b
}
func (lb buffer) printBuf() {
out := lb.buf[lb.offset:min(len(lb.buf), lb.offset+lb.maxWidth)]
fmt.Printf("\r%s%s\033[0K\r\033[%dC", lb.prompt, string(out), lb.cursor - lb.offset + len(lb.prompt))
}
func (lb *buffer) controlInput(c rune) {
switch c {
case Delete:
lb.deleteChar()
case BackSpace:
if lb.cursor > 0 {
lb.cursor--
lb.deleteChar()
}
case LeftArrow:
if lb.offset > 0 && lb.cursor - lb.offset == 0 {
lb.offset--
}
if lb.cursor > 0 {
lb.cursor--
}
case RightArrow:
// This is still mildly funky, but works enough
for ;lb.cursor - lb.offset >= lb.maxWidth && lb.cursor < len(lb.buf); {
lb.offset++
}
if lb.cursor < len(lb.buf) {
lb.cursor++
}
case Home:
lb.offset = 0
lb.cursor = 0
case End:
lb.cursor = len(lb.buf)
lb.offset = max(lb.cursor - lb.maxWidth, 0)
}
lb.printBuf()
}
func (lb *buffer) seedContent(s string) {
for _, r := range s {
lb.addChar(r, false)
}
}
func parseCursorPosition(esc string) (int, int, error) {
var row, col int
r := strings.NewReader(esc)
_, err := fmt.Fscanf(r, "\033[%d;%dR", &row, &col)
return row, col, err
}
func ReadKey(reader *bufio.Reader) (rune, error) {
char, _, err := reader.ReadRune()
if err != nil {
return 0, err
}
avail := reader.Buffered()
if char == Escape && avail > 0 {
var b strings.Builder
b.WriteRune(27)
for ; avail > 0; avail-- {
c, _, e := reader.ReadRune()
if e != nil {
break
}
b.WriteRune(c)
}
escSeq := b.String()
switch true {
case escSeq == "\033[A":
char = UpArrow
case escSeq == "\033[B":
char = DownArrow
case escSeq == "\033[C":
char = RightArrow
case escSeq == "\033[D":
char = LeftArrow
case escSeq == "\033[5~":
char = PageUp
case escSeq == "\033[6~":
char = PageDown
case isHomeKey(escSeq):
char = Home
case isEndKey(escSeq):
char = End
case isDeleteKey(escSeq):
char = Delete
case escSeq[len(escSeq)-1] == 'R':
// This is a request for cursor position
_, cols, err := parseCursorPosition(escSeq)
if err == nil {
err = fmt.Errorf("response")
}
return rune(cols), err
}
}
return char, nil
}
func isControl(c rune) bool {
switch c {
case UpArrow, DownArrow, RightArrow, LeftArrow, PageUp, PageDown, Home, End, Delete, BackSpace, CarriageReturn, NewLine, Escape:
return true
default:
return false
}
}
func isDeleteKey(seq string) bool {
switch seq {
case "\033[3~", "\033[P":
return true
default:
return false
}
}
func isHomeKey(seq string) bool {
switch seq {
case "\033[1~", "\033[7~", "\033[H", "\033OH":
return true
default:
return false
}
}
func isEndKey(seq string) bool {
switch seq {
case "\033[4~", "\033[8~", "\033[F", "\033OF":
return true
default:
return false
}
}

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termios/consts_linux.go Normal file
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// +build linux
package termios
import "syscall"
const (
getTermiosIoctl = syscall.TCGETS
setTermiosIoctl = syscall.TCSETS
)

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// +build !linux
package termios
import "syscall"
const (
getTermiosIoctl = syscall.TIOCGETA
setTermiosIoctl = syscall.TIOCSETAF
)

73
termios/termios.go Normal file
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package termios
import (
"os"
"runtime"
"syscall"
"unsafe"
)
type winsize struct {
Row uint16
Col uint16
Xpixel uint16
Ypixel uint16
}
var fd = os.Stdin.Fd()
var initial syscall.Termios
var initialSet bool = false
func ioctl(fd, request, argp uintptr) error {
if _, _, e := syscall.Syscall(syscall.SYS_IOCTL, fd, request, argp); e != 0 {
return e
}
return nil
}
func GetWindowSize() (int, int) {
var value winsize
ioctl(fd, syscall.TIOCGWINSZ, uintptr(unsafe.Pointer(&value)))
return int(value.Col), int(value.Row)
}
func getTermios() syscall.Termios {
var value syscall.Termios
err := ioctl(fd, getTermiosIoctl, uintptr(unsafe.Pointer(&value)))
if err != nil {
panic(err)
}
return value
}
func setTermios(termios syscall.Termios) {
err := ioctl(fd, setTermiosIoctl, uintptr(unsafe.Pointer(&termios)))
if err != nil {
panic(err)
}
runtime.KeepAlive(termios)
}
func SetInitialTermios() {
if !initialSet {
initial = getTermios()
initialSet = true
}
}
func SetCharMode() {
t := getTermios()
t.Lflag = t.Lflag ^ syscall.ICANON
t.Lflag = t.Lflag ^ syscall.ECHO
setTermios(t)
}
func SetLineMode() {
var t = getTermios()
t.Lflag = t.Lflag | (syscall.ICANON | syscall.ECHO)
setTermios(t)
}
func Restore() {
setTermios(initial)
}