c8bc57075b13fc1f28dcf6ac3e2f756b4c5e3101 — John Gebbie 5 months ago
initial commit
A  => .gitignore +1 -0
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A  => LICENSE +674 -0
@@ 1,674 @@
                    GNU GENERAL PUBLIC LICENSE
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A  => README.md +31 -0
@@ 1,31 @@
# Wak

Wak is a minimalist text-processing language. Programs are chiefly
a sequence of functions executed per line of input, passing their
arguments on a stack implicitly. The stack-based approach makes for
terse programs and trivial syntax.

## Install From Source

With `go` (aka `golang`) and `scdoc` installed, run:

    ./build.sh && sudo ./build.sh install

## Usage

See the [manpage](doc/wak.1.scd) and [examples](examples).

## Contact

You can send questions or patches by composing an email to

## Support My Work 👀

[Thank you!](https://liberapay.com/geb)

## License

GPLv3 only, see [LICENSE](LICENSE).

Copyright (c) 2023 John Gebbie

A  => build.sh +20 -0
@@ 1,20 @@
# ./build.sh ['install']
: "${WAK_VERSION=$(git describe --long --abbrev=12 --tags --dirty 2>/dev/null || echo 0.0)}"
: "${WAK_BINDIR=usr/local/bin}"

if [ "$*" != '' ] && [ "$*" != install ]; then
	echo bad usage
	exit 1

if ! [ "$1" ]; then
	go build -ldflags "-X main.Version=$WAK_VERSION" || exit
	echo Built Successfully.
	install -Dm755 wak -t "$WAK_DESTDIR/$WAK_BINDIR" || exit
	mkdir -p "$WAK_DESTDIR/usr/share/man/man1" || exit
	scdoc < doc/wak.1.scd > "$WAK_DESTDIR/usr/share/man/man1/wak.1" || exit
	echo Installed Successfully.

A  => command.go +77 -0
@@ 1,77 @@
package main

import (

// TODO always free resources by calling Wait()

type Command struct {
	cmd *exec.Cmd
	stdin io.WriteCloser
	stdout io.ReadCloser
	scanner *bufio.Scanner
	code int

func NewCommand(line string) (*Command, error) {
	sh := os.Getenv("SHELL")
	if sh == "" {
		sh = "/bin/sh"
	var c Command
	c.cmd = exec.Command(sh, "-c", line)
	if stdin, err := c.cmd.StdinPipe(); err == nil {
		c.stdin = stdin
	} else {
		return nil, err
	if stdout, err := c.cmd.StdoutPipe(); err == nil {
		c.stdout = stdout
		c.scanner = bufio.NewScanner(stdout)
	} else {
		return nil, err
	c.cmd.Stderr = os.Stderr
	if err := c.cmd.Start(); err != nil {
		return nil, err
	return &c, nil

func (c *Command) Receive() (string, error) {
	if c.scanner.Scan() {
		return c.scanner.Text(), nil
	return "", c.scanner.Err()

func (c *Command) Send(s string) error {
	_, err := io.WriteString(c.stdin, s)
	return err

func (c *Command) Output() (string, error) {
	data, err := io.ReadAll(c.stdout)
	if err == nil {
		_, err = c.Wait()
	} else {
		_, _ = c.Wait()
	return string(data), err

func (c *Command) Wait() (int, error) {
	err := c.cmd.Wait()
	if ee, ok := err.(*exec.ExitError); ok {
		c.code = ee.ExitCode()
	} else if err != nil {
		return 1, err
	return c.code, nil

A  => doc/wak.1.scd +440 -0
@@ 1,440 @@


*wak* - text-processing language


*wak* [*-f* _PROGFILE_ | '_PROG_'] [_FILE_...]


Wak is a text-processing language. Programs consist chiefly of a sequence of
functions executed per line of input. Arguments are passed implicitly between
functions by means of a stack. All arguments are strings but functions may
expect their arguments to represent text, numbers or regular expressions.

The first positional argument specifies the program text unless a program
file is specified with *-f* or *-F*. Any other positional arguments specify
input files to process instead of stdin.


	Specify a program file.

	Specify a program file and terminate the options, so any following
	arguments are positional arguments. Useful for shebangs lines.

*-h*, *--help*
	Print help and exit.

	Overwrite the input files with the output.

	Print the version and exit.


The rest of a line of code is ignored after any *#* (unless in a string


Along with functions, programs can contain string literals which are
quoted with *"* or *'*, or are a sequence of *+-.0123456789* representing
a number. Their operation is to put their string on the stack. There are no
escape sequences.


Code can be executed conditionally with an *if* expression. Its simplest
form is:

*if {* _code_ *}*

where *if* takes an argument off the stack and if it represents true (a
non-zero number), the code is executed.

In the form:

*if {* _code1_ *} else {* _code2_ *}*

If the argument represents true, the first code is executed, otherwise the
second code is executed.

Furthermore, *if* expressions can be chained with conditions between *else*
and *if*, like so:

*if {* _code1_ *} else* _code2_ *if {* _code3_ *}*


Code can be executed indefinitely with *for {* _code_ *}* and there are
several loop related functions.


The start or end of each program file may have *BEGIN {* _code_ *}*, *END {*
_code_ *}* and *DEFINE {* _code_ *}*.

The code within a *BEGIN {* _code_ *}* is executed once in the beginning,
before any input is read.

The code within an *END {* _code_ *}* is executed once at the end.

Each *DEFINE* _name_ *{* _code_ *}* defines or redefines a function that's
available for following code.

A program with only *BEGIN* and *DEFINE* blocks terminates without reading


Here each builtin function is listed with a pictorial showing its effect
on the top of the stack. The following symbols are used to indicate what
elements represent:

	A generic string, perhaps representing (UTF-8) text

	A number

	A count (a non-negative whole number)

	An integer (a whole number)

	A regular expression

	Zero or more strings

The number an argument represents is determined by the sequence of
*+-.0123456789* at the start of the string (ignoring whitespace). If there
is no sequence, it represents zero. If representing a count or integer,
it is rounded to the nearest whole number.

Regular expressions are of the same general syntax used by Perl, Python
and other languages. More precisely, the syntax of RE2 described at
https://github.com/google/re2/wiki/Syntax, except for \\C.


*p* ( s -- )
	Prints a string.

*P* ( s -- )
	Prints a string and a newline.

*?* ( -- )
	Prints the stack for debugging, leaving it untouched.


*r* ( -- s )
	Gives the current input line (aka record).

*f* ( i -- s )
	Gives the *i*th field (non-whitespace part) of the current input line,
	else an empty string. Zero gives the first, negative one gives the
	last, and so on.

*fc* ( -- c )
	Gives number of fields in the current input line.

*n* ( -- c )
	Gives the number of input lines read.

*N* ( -- c )
	Gives the number of input lines read of the current input file.


*c* ( -- c )
	Gives the number of stack elements.

*drop* ( s -- )
	Discards an element.

*dup* ( s -- s s )
	Duplicates an element.

*swap* ( s1 s2 -- s2 s1 )
	Swaps two elements.

*rot* ( s1 s2 s3 -- s2 s3 s1 )
	Cycles three elements.

*cycle* ( s... c -- s... c )
	Cycles c elements.

*item* ( s... c i -- s... c s )
	Gives a copy of the *i*th element of c elements. Zero gives the first,
	negative one gives the last, and so on.

*!* ( s -- )
	Stores an element which can then be retrieved by *@* in the same
	*DEFINE* function or top-level scope.

*@* ( -- s )
	Gives the last element stored with *!* in the same *DEFINE* function
	or top-level scope, else zero.


*nl* ( -- s )
	Gives a string that only contains a newline.

*tab* ( -- s )
	Gives a string that only contains a tab.

*len* ( s -- c )
	Gives the number of characters (Unicode code points) in a string.

*lower* ( s1 -- s2 )
	Converts a string to lowercase.

*upper* ( s1 -- s2 )
	Converts a string to uppercase.

*ord* ( s -- n )
	Gives the first Unicode code point of a string.

*chr* ( n -- s )
	Gives the string of a Unicode code point.

*is* ( s1 s2 -- 0|1 )
	Gives whether two strings are the same.

*isnt* ( s1 s2 -- 0|1 )
	Gives whether two strings are not the same.

*scale* ( s1 i -- s2 )
	Gives a string repeated i times and flipped if i is negative.

*,* ( s1 s2 -- s3 )
	Joins two strings.

*join* ( s... c s1 -- s2 )
	Joins c strings with s1 between each.

*shelljoin* ( s... c -- s )
	Quotes strings according to sh's word-splitting and joins them with
	spaces in between.

*~* ( s re -- 0|1 )
	Gives whether a string matches a regular expression.

*!~* ( s re -- 0|1 )
	Gives whether a string doesn't match a regular expression.

*escape* ( s -- re )
	Escapes all regular expression metacharacters in a string, giving
	a regular expression to match for the string literally.

*split* ( s re -- s... c )
	Splits a string into the parts separated by a regular expression. Any
	capturing groups in the regular expression invert whether that part
	is discarded.

*extract* ( s re -- s... c )
	Splits a string into the parts matched by a regular expression. Any
	capturing groups in the regular expression invert whether that part
	is extracted.

*sub* ( s1 re s2 -- s3 )
	Substitutes the first occurrence of a regular expression in s1 with
	s2. s2 can contain the likes of *${*_number_*}* to denote the match
	of a capture group, with *${0}* denoting the entire match.

*gsub* ( s1 re s2 -- s3 )
	The same as *sub* but replaces all occurrences.


*<* ( n1 n2 -- 0|1 )
	Gives whether n1 is less than n2.

*<=* ( n1 n2 -- 0|1 )
	Gives whether n1 is less than or equal to n2.

*>* ( n1 n2 -- 0|1 )
	Gives whether n1 is greater than n2.

*>=* ( n1 n2 -- 0|1 )
	Gives whether n1 is greater than or equal to n2.

*=* ( n1 n2 -- 0|1 )
	Gives whether two numbers are equal.

*!=* ( n1 n2 -- 0|1 )
	Gives whether two numbers are not equal.

*and* ( n1 n2 -- n1|n2 )
	Gives n2 if n1 is non-zero, else zero.

*or* ( n1 n2 -- n1|n2 )
	Gives n1 if n1 is non-zero, else n2.

*+* ( n1 n2 -- n3 )
	Gives the addition of two numbers.

*-* ( n1 n2 -- n3 )
	Gives the subtraction of two numbers.

*\** ( n1 n2 -- n3 )
	Gives the multiplication of two numbers.

*/* ( n1 n2 -- n3 )
	Gives the division of two numbers.

*mod* ( n1 n2 -- n3 )
	Gives the modulo of two numbers.

*floor* ( n1 -- n2 )
	Gives the greatest integer less than or equal to a number.

*pow* ( n1 n2 -- n3 )
	Gives n1 to the power of n2.

*sqrt* ( n1 -- n2 )
	Gives the square root of a number.

*cos* ( n1 -- n2 )
	Gives the cosine of an angle of radians.

*sin* ( n1 -- n2 )
	Gives the sine of an angle of radians.

*atan2* ( n1 n2 -- n3 )
	Gives the arctangent of y and x, where n1 is y and n2 is x.

*log* ( n1 -- n2 )
	Gives the natural logarithm of a number.

*exp* ( n1 -- n2 )
	Gives e (the mathematical constant) to the power of a number.

*rand* ( -- n )
	Gives a pseudo-random number in the range [0.0,1.0).

*seed* ( i -- )
	Sets the seed used by *rand*, determining the sequence of results.


Loop functions must be within a *for* loop.

*i* ( -- c )
	Gives how times the *for* loop has looped.

*break* ( -- )
	Terminates the *for* loop.

*while* ( n -- )
	Terminates the *for* loop if n is zero.

*iterate* ( s... c -- s... c )
	Cycles c elements if the *for* loop has looped less than c times,
	else terminates the *for* loop.


*arg* ( i -- s )
	Gives the *i*th command-line positional argument. Zero gives the
	first, negative one gives the last, and so on.

*argc* ( -- c )
	Gives the number of command-line positional arguments.

*argi* ( -- c )
	Gives the number of input files processed.

*env* ( s1 -- s2 )
	Gives the value of an environment variable, or an empty string.

*exit* ( i -- )
	Sets the return code to terminate with and jumps to end of the program.


Key value pairs can be stored in collections referred to as maps. At startup
the current map's name is the empty string.

*map* ( s -- )
	Switches to a new or existing map by name.

*set* ( s1 s2 -- )
	Assigns a key value pair in the current map. s1 is used as the value,
	s2 the key.

*+set* ( n s -- )
	Increments the value of a key in the current map by n, or sets it
	to n if the key is unassigned.

*unset* ( s -- )
	Unassigns a key in the current map.

*get* ( s1 -- s2 )
	Gives the value of a key in the current map, or an empty string if
	the key is unassigned.

*keys* ( -- s... c )
	Gives the keys of the current map in an arbitrary order, and how many.

*keyc* ( -- c )
	Gives the number of keys/values in the current map.


*run* ( s -- )
	Starts a shell command line running in the background, and makes it
	the current command for other command functions.

*command* ( s -- )
	Switches to an existing command by the command line used with *run*.

*send* ( s -- )
	Writes a string to the current command's stdin. You will likely want
	to supply a trailing newline.

*receive* ( -- s )
	Reads and gives a line from the current command's remaining stdout,
	or gives an empty string if it's exhausted.

*output* ( -- s )
	Reads and gives all the current command's remaining stdout after
	closing its stdin.

*wait* ( -- i )
	Waits for the current command to terminate after closing its stdin,
	if not already terminated, and gives the return code.


Print a file's contents uppercase:

$ *wak 'r upper P' myfile*

Print lines of a file joined if they end with a backslash:

$ *wak 'r "\\\\$" split 2 = if { , p } else { P }' myfile*

Print each field of stdin multiplied by two and joined with dashes:

$ *wak 'for { i fc < while i f 2 \* } c "-" join P'*

Print unique lines from multiple files:

$ *wak 'r get 0 = if { r P  1 r set }' myfile myfile2*


John Gebbie

A  => examples/braces.input +6 -0
@@ 1,6 @@
if 1 {
do A }
elif 2 {
do B
if 3 { do C } }
if 4 { do D } else { do E }

A  => examples/braces.wak +26 -0
@@ 1,26 @@
#!/usr/bin/env -S wak -F
# Formats and indents braces.

for {
	"^\s*" "" sub
	dup len 0 = if { drop break }
	"^([^{}]*){" split 3 = if {
		rot drop swap
		tab @ scale p p "{" P
		@ 1 + !
	} else "^([^{}]*)}" split 3 = if {
		rot drop swap
		dup len if {
			tab @ scale p
		} else {
		@ 1 - !
		tab @ scale p "}" P
	} else {
		tab @ scale p P

A  => examples/snake.wak +81 -0
@@ 1,81 @@
#!/usr/bin/env -S wak -F

DEFINE width { 16 }
DEFINE height { 16 }

# ( s -- 0|1 ) Gives whether a string is on the stack.
DEFINE have {
	! c for { dup i > while i item @ is if { -1 break } }
	-1 = if { drop 1 } else { 0 }

# ( s -- ) Moves the cursor.
DEFINE go { 27 chr "[" , swap , "H" , p }

DEFINE spawn_apple {
	for {
		height rand * floor 2 +  width rand * floor 2 +  2 ";" join !
		@ have while
	@ go "o" p
	@ "apple" set

DEFINE exit {
	height 3 + go
	27 chr "[?25h" , p # unhide the cursor
	"stty -F/dev/tty sane" run wait drop

	27 chr "[2J" , p # clear the screen
	27 chr "[?25l" , p # hide the cursor
	"0" go

	"#" width 2 + scale P
	"#" " " width scale , "#" , nl , 16 scale p
	"#" width 2 + scale P
	"W A S D to move" P

	height 2 / 2 +  width 2 / 1 +  2 ";" join  dup go "@" p
	height 2 / 1 +  width 2 / 1 +  2 ";" join  dup go "@" p
	height 2 /      width 2 / 1 +  2 ";" join  dup go "@" p


	"stty -F/dev/tty raw min 0 time 2 -echo" run

	-1 "v" set  0 "h" set
	for {
		"dd bs=1 count=1 if=/dev/tty 2>/dev/null" run output !
		@ 3 chr is if { 1 exit }
		@ "w" is if {
			"h" get if { -1 "v" set  0 "h" set }
		} else @ "s" is if {
			"h" get if { 1 "v" set  0 "h" set }
		} else @ "a" is if {
			"v" get if { -1 "h" set  0 "v" set }
		} else @ "d" is if {
			"v" get if { 1 "h" set  0 "v" set }

		dup ";" split drop "x" set "y" set
		"v" get "y" +set
		"h" get "x" +set
		"y" get "x" get 2 ";" join !
		@ go "@" p

		@ "apple" get is if {
		} else {
			c cycle drop go " " p

		@ have if { 0 exit }
		"y" get 2 <  "y" get height 1 + > or if { 0 exit }
		"x" get 2 <  "x" get width 1 + > or if { 0 exit }


A  => go.mod +5 -0
@@ 1,5 @@
module git.sr.ht/~geb/wak

go 1.21.0

require git.sr.ht/~geb/opt v0.0.0-20230911153257-e72225a1933c

A  => go.sum +2 -0
@@ 1,2 @@
git.sr.ht/~geb/opt v0.0.0-20230911153257-e72225a1933c h1:gIC1gnCgoasPHks1x6MB+bgDmIWMxKc5HIJPJrsV5Ck=
git.sr.ht/~geb/opt v0.0.0-20230911153257-e72225a1933c/go.mod h1:S6h1g8P7DyG7i7YIHZ5IpYbC6lzZB9DYIEl8PyXOmsg=

A  => stack.go +807 -0
@@ 1,807 @@
package main

import (

func shellquote(s string) string {
	parts := strings.Split(s, "'")
	var sb strings.Builder
	for _, p := range parts[1:] {
	return sb.String()

func submatchIndices(s string, re *regexp.Regexp, n int) []int {
	var indices []int
	for _, loc := range re.FindAllStringSubmatchIndex(s, n) {
		for _, index := range loc {
			if index >= 0 {
				indices = append(indices, index)
	return indices

func quote(e Elem) string {
	return fmt.Sprintf("%q", e.Str())

type Elem interface {
	Str() Str
	Num() Num

type Str string

func (s Str) Str() Str {
	return s
func (s Str) Num() Num {
	f, _ := parseNumber(string(s))
	return Num(f)

type Num float64

func (n Num) Str() Str {
	return Str(strconv.FormatFloat(float64(n), 'f', -1, 64))
func (n Num) Num() Num {
	return n

type Stack struct {
	Executor *Executor
	Elems []Elem

func (s *Stack) Push(elems ...Elem) {
	s.Elems = append(s.Elems, elems...)

// the underlying array may change
func (s *Stack) Pop(n int) []Elem {
	if n > len(s.Elems) {
		s.Executor.Fatal("stack underflow")
	elems := s.Elems[len(s.Elems)-n:]
	s.Elems = s.Elems[:len(s.Elems)-n]
	return elems

// the underlying array may change
func (s *Stack) Peek(n int) []Elem {
	if n > len(s.Elems) {
		s.Executor.Fatal("stack underflow")
	return s.Elems[len(s.Elems)-n:]

func (s *Stack) toCount(e Elem) int {
	c := int(math.Round(float64(e.Num())))
	if c < 0 {
		s.Executor.Fatal("negative count argument: ", quote(e))
	return c

//word p
func (s *Stack) Print() {
	fmt.Fprint(s.Executor.Output, s.Pop(1)[0].Str())

//word P
func (s *Stack) PrintLine() {
	fmt.Fprintln(s.Executor.Output, s.Pop(1)[0].Str())

//word ?
func (s *Stack) DebugStack() {
	var sb strings.Builder
	sb.WriteString(fmt.Sprintf("[%d]", len(s.Elems)))
	for i := range s.Elems {
		sb.WriteString(fmt.Sprintf(" %q", s.Elems[i].Str()))
	fmt.Fprintln(os.Stderr, sb.String())

//word r
func (s *Stack) Record() {

//word f
func (s *Stack) Field() {
	i := int(math.Round(float64(s.Pop(1)[0].Num())))
	fields := strings.Fields(s.Executor.Record)
	if i < 0 {
		i += len(s.Executor.Args)
	if i < len(fields) {
	} else {

//word fc
func (s *Stack) FieldCount() {

//word n
func (s *Stack) RecordNum() {

//word N
func (s *Stack) FileRecordNum() {

//word c
func (s *Stack) Count() {

//word drop
func (s *Stack) Drop() {

//word dup
func (s *Stack) Dup() {

//word swap
func (s *Stack) Swap() {
	e := s.Peek(2)
	e[0], e[1] = e[1], e[0]

//word rot
func (s *Stack) Rot() {
	e := s.Peek(3)
	e[0], e[1], e[2] = e[1], e[2], e[0]

//word cycle
func (s *Stack) Cycle() {
	c := s.toCount(s.Peek(1)[0])
	if c > 0 {
		elems := s.Peek(c+1)[:c]
		e := elems[0]
		copy(elems, elems[1:])
		elems[len(elems)-1] = e

//word item
func (s *Stack) Item() {
	i := int(math.Round(float64(s.Peek(1)[0].Num())))
	c := s.toCount(s.Peek(2)[0])
	if c == 0 {
		s.Executor.Fatal("count of zero: ", quote(s.Peek(2)[0]))
	elems := s.Peek(c+2)[:c]
	if i < 0 {
		i += c
	if i >= c {
		i := quote(s.Peek(1)[0])
		c := quote(s.Peek(2)[0])
		s.Executor.Fatal("out of range index: ", i, " count: ", c)
	s.Elems[len(s.Elems)-1] = elems[i]

//word !
func (s *Stack) Store() {
	s.Executor.Variable = s.Pop(1)[0]

//word @
func (s *Stack) Fetch() {

//word nl
func (s *Stack) Newline() {

//word tab
func (s *Stack) Tab() {

//word len
func (s *Stack) Len() {

//word lower
func (s *Stack) Lower() {

//word upper
func (s *Stack) Upper() {

//word ord
func (s *Stack) Ord() {
	str := string(s.Pop(1)[0].Str())
	if len(str) > 0 {
	} else {

//word chr
func (s *Stack) Chr() {
	i := int(math.Round(float64(s.Pop(1)[0].Num())))

//word is
func (s *Stack) Is() {
	e := s.Pop(2)
	if e[0].Str() == e[1].Str() {
	} else {

//word isnt
func (s *Stack) Isnt() {
	e := s.Pop(2)
	if e[0].Str() != e[1].Str() {
	} else {

//word scale
func (s *Stack) Scale() {
	i := int(math.Round(float64(s.Pop(1)[0].Num())))
	str := string(s.Pop(1)[0].Str())
	if i >= 0 {
		s.Push(Str(strings.Repeat(str, i)))
	} else {
		runes := []rune(str)
		for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
			runes[i], runes[j] = runes[j], runes[i]
		s.Push(Str(strings.Repeat(string(runes), -i)))

//word ,
func (s *Stack) Append() {
	e := s.Pop(2)
	s.Push(Str(string(e[0].Str()) + string(e[1].Str())))

//word join
func (s *Stack) Join() {
	sep := s.Pop(1)[0].Str()
	c := s.toCount(s.Pop(1)[0])
	e := s.Pop(c)
	var sb strings.Builder
	for i := range e {
		if i != len(e)-1 {

//word shelljoin
func (s *Stack) Shelljoin() {
	c := s.toCount(s.Pop(1)[0])
	e := s.Pop(c)
	var sb strings.Builder
	for i := range e {
		if i != len(e)-1 {
			sb.WriteRune(' ')

//word ~
func (s *Stack) Match() {
	re, err := regexp.Compile(string(s.Pop(1)[0].Str()))
	if err != nil {
	if re.MatchString(string(s.Pop(1)[0].Str())) {
	} else {

//word !~
func (s *Stack) NotMatch() {
	re, err := regexp.Compile(string(s.Pop(1)[0].Str()))
	if err != nil {
	if !re.MatchString(string(s.Pop(1)[0].Str())) {
	} else {

//word escape
func (s *Stack) Escape() {

//word split
func (s *Stack) Split() {
	re, err := regexp.Compile(string(s.Pop(1)[0].Str()))
	if err != nil {
	str := string(s.Pop(1)[0].Str())
	indices := submatchIndices(str, re, -1)
	if len(indices) > 0 {
		for i := 1; i+1 < len(indices); i += 2 {
		s.Push(Num(len(indices)/2 + 1))
	} else {

//word extract
func (s *Stack) Extract() {
	re, err := regexp.Compile(string(s.Pop(1)[0].Str()))
	if err != nil {
	str := string(s.Pop(1)[0].Str())
	indices := submatchIndices(str, re, -1)
	for i := 0; i+1 < len(indices); i += 2 {

//word sub
func (s *Stack) Sub() {
	e := s.Pop(3)
	re, err := regexp.Compile(string(e[1].Str()))
	if err != nil {
	done := false
	r := re.ReplaceAllStringFunc(string(e[0].Str()), func(m string) string {
		if done {
			return m
		done = true
		return re.ReplaceAllString(m, string(e[2].Str()))

//word gsub
func (s *Stack) Gsub() {
	e := s.Pop(3)
	re, err := regexp.Compile(string(e[1].Str()))
	if err != nil {
	s.Push(Str(re.ReplaceAllString(string(e[0].Str()), string(e[2].Str()))))

//word <
func (s *Stack) LessThan() {
	e := s.Pop(2)
	if e[0].Num() < e[1].Num() {
	} else {

//word <=
func (s *Stack) LessThanOrEqual() {
	e := s.Pop(2)
	if e[0].Num() <= e[1].Num() {
	} else {

//word >
func (s *Stack) GreaterThan() {
	e := s.Pop(2)
	if e[0].Num() > e[1].Num() {
	} else {

//word >=
func (s *Stack) GreaterThanOrEqual() {
	e := s.Pop(2)
	if e[0].Num() >= e[1].Num() {
	} else {

//word =
func (s *Stack) Equal() {
	e := s.Pop(2)
	if e[0].Num() == e[1].Num() {
	} else {

//word !=
func (s *Stack) NotEqual() {
	e := s.Pop(2)
	if e[0].Num() != e[1].Num() {
	} else {

//word and
func (s *Stack) And() {
	e := s.Pop(2)
	if int(e[0].Num()) != 0 {
	} else {

//word or
func (s *Stack) Or() {
	e := s.Pop(2)
	if int(e[0].Num()) != 0 {
	} else if int(e[1].Num()) != 0 {
	} else {

//word +
func (s *Stack) Add() {
	e := s.Pop(2)
	s.Push(e[0].Num() + e[1].Num())

//word -
func (s *Stack) Subtract() {
	e := s.Pop(2)
	s.Push(e[0].Num() - e[1].Num())

//word *
func (s *Stack) Multiply() {
	e := s.Pop(2)
	s.Push(e[0].Num() * e[1].Num())

//word /
func (s *Stack) Divide() {
	e := s.Pop(2)
	if e[1].Num() == 0 {
		s.Executor.Fatal("division by zero: ", quote(e[1]))
	s.Push(e[0].Num() / e[1].Num())

//word mod
func (s *Stack) Mod() {
	e := s.Pop(2)
	a, b := float64(e[0].Num()), float64(e[1].Num())
	if b == 0 {
		s.Executor.Fatal("modulo by zero: ", quote(e[1]))
	s.Push(Num(a - b * math.Floor(a / b)))

//word floor
func (s *Stack) Floor() {

//word pow
func (s *Stack) Pow() {
	e := s.Pop(2)
	p := math.Pow(float64(e[0].Num()), float64(e[1].Num()))
	if math.IsNaN(p) || math.IsInf(p, 0) {
		s.Executor.Fatal("bad pow: ", quote(e[0]), " ", quote(e[1]))

//word sqrt
func (s *Stack) Sqrt() {
	e := s.Pop(1)[0]
	n := float64(e.Num())
	if n < 0 {
		s.Executor.Fatal("square root of a negative number: ", quote(e))

//word cos
func (s *Stack) Cos() {

//word sin
func (s *Stack) Sin() {

//word atan2
func (s *Stack) Atan2() {
	e := s.Pop(2)
	s.Push(Num(math.Atan2(float64(e[0].Num()), float64(e[1].Num()))))

//word log
func (s *Stack) Log() {
	e := s.Pop(1)[0]
	n := float64(e.Num())
	if n == 0 {
		s.Executor.Fatal("log of zero: ", quote(e))
	if n < 0 {
		s.Executor.Fatal("log of a negative number: ", quote(e))

//word exp
func (s *Stack) Exp() {
	e := s.Pop(1)[0]
	exp := math.Exp(float64(e.Num()))
	if math.IsInf(exp, 0) {
		s.Executor.Fatal("bad exp: ", quote(e))

//word rand
func (s *Stack) Rand() {

//word seed
func (s *Stack) Seed() {

//word i
func (s *Stack) Index() {

//word break
func (s *Stack) Break() {
	s.Executor.Break = true

//word while
func (s *Stack) While() {
	s.Executor.Break = s.Pop(1)[0].Num() == 0

//word iterate
func (s *Stack) Iterate() {
	c := s.toCount(s.Peek(1)[0])
	if s.Executor.LoopIndices[len(s.Executor.LoopIndices)-1] < c {
	} else {
		s.Executor.Break = true

//word arg
func (s *Stack) Arg() {
	i := int(math.Round(float64(s.Pop(1)[0].Num())))
	if i < 0 {
		i += len(s.Executor.Args)
	if i < len(s.Executor.Args) {
	} else {

//word argc
func (s *Stack) Argc() {

//word argi
func (s *Stack) Argi() {

//word env
func (s *Stack) Env() {

//word exit
func (s *Stack) Exit() {
	s.Executor.Code = int(math.Round(float64(s.Pop(1)[0].Num())))
	s.Executor.Exit = true

//word map
func (s *Stack) Map() {
	name := string(s.Pop(1)[0].Str())
	if s.Executor.Maps[name] == nil {
		s.Executor.Maps[name] = make(map[string]Elem)
	s.Executor.Map = s.Executor.Maps[name]

//word set
func (s *Stack) Set() {
	s.Executor.Map[string(s.Pop(1)[0].Str())] = s.Pop(1)[0]

//word +set
func (s *Stack) PlusSet() {
	e := s.Pop(2)
	key := string(e[1].Str())
	if v, ok := s.Executor.Map[key]; ok {
		s.Executor.Map[key] = Num(float64(v.Num()) + float64(e[0].Num()))
	} else {
		s.Executor.Map[key] = e[0]

//word unset
func (s *Stack) Unset() {
	delete(s.Executor.Map, string(s.Pop(1)[0].Str()))

//word get
func (s *Stack) Get() {
	if e, ok := s.Executor.Map[string(s.Pop(1)[0].Str())]; ok {
	} else {

//word keys
func (s *Stack) Keys() {
	for key := range s.Executor.Map {

//word keyc
func (s *Stack) Keyc() {

//word run
func (s *Stack) Run() {
	line := string(s.Pop(1)[0].Str())
	c, err := NewCommand(line)
	if err != nil {
	s.Executor.Commands[line] = c
	s.Executor.Command = c

//word command
func (s *Stack) Command() {
	line := string(s.Pop(1)[0].Str())
	c, ok := s.Executor.Commands[line]
	if !ok {
		s.Executor.Fatal("command not found: ", fmt.Sprintf("%q", line))
	s.Executor.Commands[line] = c
	s.Executor.Command = c

//word send
func (s *Stack) Send() {
	if s.Executor.Command == nil {
		s.Executor.Fatal("no command exists")
	err := s.Executor.Command.Send(string(s.Pop(1)[0].Str()))
	if err != nil {

//word receive
func (s *Stack) Receive() {
	if s.Executor.Command == nil {
		s.Executor.Fatal("no command exists")
	output, err := s.Executor.Command.Receive()
	if err != nil {

//word output
func (s *Stack) Output() {
	if s.Executor.Command == nil {
		s.Executor.Fatal("no command exists")
	output, err := s.Executor.Command.Output()
	if err != nil {

//word wait
func (s *Stack) Wait() {
	code, err := s.Executor.Command.Wait()
	if err != nil {

A  => wak.go +632 -0
@@ 1,632 @@
package main

import (

var Version string

var debug = os.Getenv("WAK_DEBUG") != ""

func usage() {
	fmt.Fprintln(os.Stderr, `Usage: wak [-f PROGFILE | 'PROG'] [FILE...]

Wak is a text-processing language.

-f PROGFILE  Specify a program file.
-F PROGFILE  Specify a program file and terminate the options.
-i           Overwrite the input files with the output.
--version    Print the version and exit.

See 'man wak' for the documentation.`)

func fatal(a ...any) {
	fmt.Fprintln(os.Stderr, "wak:", fmt.Sprint(a...))

func cutAny(s, chars string) (before, after string, found bool) {
	if i := strings.IndexAny(s, chars); i >= 0 {
		return s[:i], s[i+1:], true
	return s, "", false

type Token interface {
	Token() string

type token string
func (t token) Token() string { return string(t) }

type Block struct {
	Block []Token
type Number struct {
	Number float64
type String string
func (s String) Token() string { return string(s) }
type Wordlike string
func (w Wordlike) Token() string { return string(w) }

type Define struct {
	Block []Token
type For Block
type If struct {
	Clauses [][]Token
type Word struct {
	Func func()

type Rules struct {
	Begins, Ends []Block

type Prog struct {
	Filename string
	Code string

func progFatal(progs []*Prog, at, prefix string, a ...any) {
	for _, prog := range progs {
		p1 := unsafe.Pointer(unsafe.StringData(prog.Code))
		p2 := unsafe.Pointer(unsafe.StringData(at))
		i := int(uintptr(p2) - uintptr(p1))
		if i < 0 || i > len(prog.Code) {
		lineNum := strings.Count(prog.Code[:i], "\n") + 1
		start := strings.LastIndex(prog.Code[:i], "\n")
		if start == -1 {
			start = 0
		runeNum := len([]rune(prog.Code[start:i])) + 1
		var sb strings.Builder
		if prog.Filename != "" {
			sb.WriteString(prog.Filename + " ")
		sb.WriteString(fmt.Sprintf("%d,%d", lineNum, runeNum))
		if prefix != "" {
			sb.WriteString(" " + prefix)
		sb.WriteString(": ")
		fatal(sb.String(), fmt.Sprint(a...))

type Parser struct {
	Defines map[string]Block
	InLoop bool
	WordFunc func(word string) func()

func (p *Parser) Fatal(token string, a ...any) {
	progFatal([]*Prog{p.Prog}, token, "parse error", a...)

func parseNumber(s string) (float64, bool) {
	s = strings.TrimSpace(s)
	for _, r := range s {
		if !strings.ContainsRune("+-.0123456789", r) {
			return 0, false
	f, err := strconv.ParseFloat(s, 64)
	return f, err == nil

func (p *Parser) Tokenize(code string) []Token {
	var tokens []Token
	for i := 0; i < len(code); i++ {
		if code[i] == '"' || code[i] == '\'' {
			s, _, ok := strings.Cut(code[i+1:], string(code[i]))
			if ok {
				tokens = append(tokens, String(s))
				i += len(s) + 1
			} else {
				p.Fatal(code[i:], "unterminated ", string(code[i]))
		} else if code[i] == '{' {
			j := i+1
			nesting := 0
			inQuote := 0
			for ; j < len(code); j++ {
				if inQuote == 1 {
					if code[j] == '"' {
						inQuote = 0
				} else if inQuote == 2 {
					if code[j] == '\'' {
						inQuote = 0
				} else if code[j] == '"' {
					inQuote = 1
				} else if code[j] == '\'' {
					inQuote = 2
				} else if code[j] == '{' {
				} else if code[j] == '}' {
					if nesting == 0 {
			if j < len(code) {
				block := Block{token(code[i:i+1]), p.Tokenize(code[i+1:j])}
				tokens = append(tokens, block)
				i = j
			} else {
				p.Fatal(code[i:], "unterminated {")
		} else if code[i] == '#' {
			s, _, _ := strings.Cut(code[i+1:], "\n")
			i += len(s)
		} else {
			s, _, _ := cutAny(code[i:], " \t\n#\"'{")
			if len(s) > 0 {
				if n, ok := parseNumber(s); ok {
					tokens = append(tokens, Number{token(s), n})
				} else {
					tokens = append(tokens, Wordlike(s))
				i += len(s)-1
	return tokens

func (p *Parser) parseWord(word string) Token {
	if block, ok := p.Defines[word]; ok {
		return Define(block)
	} else if f := p.WordFunc(word); f != nil {
		if !p.InLoop {
			switch word {
			case "i", "break", "while", "iterate":
				p.Fatal(word, "unexpected ", word)
		return Word{token(word), f}
	} else {
		p.Fatal(word, "unknown word: ", word)

func (p *Parser) parseIf(tokens []Token) (If, int) {
	var if_ If
	i := 0
	if word, ok := tokens[i].(Wordlike); ok {
		if word != "if" {
		if_.token = token(word)
	if block, ok := tokens[i].(Block); ok {
		if_.Clauses = append(if_.Clauses, p.Parse(block.Block))
	} else {
		p.Fatal(tokens[i].Token(), "expected { not ", tokens[i].Token())
	for ; i+1 < len(tokens); i++ {
		if tokens[i+1] == Wordlike("else") {
			i += 2
			var cond []Token
			for ; i < len(tokens); i++ {
				if tokens[i] == Wordlike("if") {
					elif, j := p.parseIf(tokens[i:])
					i += j
					if_.Clauses = append(if_.Clauses, cond)
					if_.Clauses = append(if_.Clauses, elif.Clauses...)
					return if_, i
				} else if block, ok := tokens[i].(Block); ok {
					if len(cond) > 0 {
						if_.Clauses = append(if_.Clauses, cond, p.Parse(block.Block))
					} else {
						if_.Clauses = append(if_.Clauses, p.Parse(block.Block))
					return if_, i
				} else if stat, j := p.parseStatement(tokens[i:]); j > 0 {
					cond = append(cond, stat)
				} else if word, ok := tokens[i].(Wordlike); ok {
					cond = append(cond, p.parseWord(string(word)))
				} else {
					cond = append(cond, tokens[i])
		} else {
	return if_, i

func (p *Parser) parseStatement(tokens []Token) (Token, int) {
	if word, ok := tokens[0].(Wordlike); ok {
		switch word {
		case "for", "if":
			if len(tokens) < 2 {
				p.Fatal(p.Code[len(p.Code)-1:], "expected { not EOF")
			if block, ok := tokens[1].(Block); ok {
				switch word {
				case "for":
					l := p.InLoop
					p.InLoop = true
					block := p.Parse(block.Block)
					p.InLoop = l
					return For{token(word), block}, 1
				case "if":
					return p.parseIf(tokens)
			} else {
				p.Fatal(tokens[1].Token(), "expected { not ", tokens[1].Token())
		case "BEGIN", "DEFINE", "END":
			p.Fatal(string(word), "unexpected ", word)
	return nil, 0

func (p *Parser) Parse(tokens []Token) []Token {
	var elements []Token
	for i := 0; i < len(tokens); i++ {
		if stat, j := p.parseStatement(tokens[i:]); j > 0 {
			i += j
			elements = append(elements, stat)
		} else if word, ok := tokens[i].(Wordlike); ok {
			elements = append(elements, p.parseWord(string(word)))
		} else if block, ok := tokens[i].(Block); ok {
			p.Fatal(block.Token(), "unexpected {")
		} else {
			elements = append(elements, tokens[i])
	return elements

func (p *Parser) parseRule(rules *Rules, defs map[string]Block, tokens []Token) int {
	if word, ok := tokens[0].(Wordlike); ok {
		switch word {
		case "BEGIN", "END":
			if len(tokens) < 2 {
				p.Fatal(p.Code[len(p.Code)-1:], "expected { not EOF")
			if block, ok := tokens[1].(Block); ok {
				switch word {
				case "BEGIN":
					begin := Block{block.token, p.Parse(block.Block)}
					rules.Begins = append(rules.Begins, begin)
					return 1
				case "END":
					end := Block{block.token, p.Parse(block.Block)}
					rules.Ends = append(rules.Ends, end)
					return 1
			} else {
				p.Fatal(tokens[1].Token(), "expected { not ", tokens[1].Token())
		case "DEFINE":
			if len(tokens) < 2 {
				p.Fatal(p.Code[len(p.Code)-1:], "expected name not EOF")
			name, ok := tokens[1].(Wordlike)
			if !ok {
				p.Fatal(tokens[1].Token(), "expected name not ", tokens[1].Token())
			switch name {
			case "BEGIN", "DEFINE", "END", "for", "if":
				p.Fatal(tokens[1].Token(), "name is reserved: ", name)
			if len(tokens) < 3 {
				p.Fatal(p.Code[len(p.Code)-1:], "expected { not EOF")
			block, ok := tokens[2].(Block)
			if !ok {
				p.Fatal(tokens[2].Token(), "expected { not ", tokens[2].Token())
			defs[string(name)] = Block{token(name), p.Parse(block.Block)}
			return 2
	return 0

func (p *Parser) ParseTop(rules *Rules, defs map[string]Block, tokens []Token) int {
	i := 0
	for ; i < len(tokens); i++ {
		if j := p.parseRule(rules, defs, tokens[i:]); j > 0 {
			i += j
		} else {
	return i

func (p *Parser) ParseBottom(rules *Rules, defs map[string]Block, tokens []Token) int {
	i := len(tokens)-2
	for ; i >= 0; i -= 2 {
		if p.parseRule(rules, defs, tokens[i:]) == 0 {
			if i > 0 && p.parseRule(rules, defs, tokens[i-1:]) > 0 {
			} else {
	return i+2

type Executor struct {
	Progs []*Prog
	Args []string
	Inplace bool

	ArgIndex int
	Record string
	RecordNum, FileRecordNum int
	Variable Elem
	Maps map[string]map[string]Elem
	Map map[string]Elem
	Commands map[string]*Command
	Command *Command

	Output io.ReadWriter
	Stack *Stack
	LoopIndices []int
	Break bool
	Exit bool
	Code int
	Fatal func(a ...any)

func (ex *Executor) Execute(recipe []Token) {
	for _, tok := range recipe {
		if ex.Break {
			ex.LoopIndices = ex.LoopIndices[:len(ex.LoopIndices)-1]
			ex.Break = false
		if ex.Exit {
			ex.LoopIndices = nil
		ex.Fatal = func(a ...any) {
			progFatal(ex.Progs, tok.Token(), tok.Token(), a...)
		switch t := tok.(type) {
		case Number:
		case String:
		case For:
			ex.LoopIndices = append(ex.LoopIndices, -1)
			n := len(ex.LoopIndices)
			for len(ex.LoopIndices) >= n {
		case If:
			if ex.Stack.Pop(1)[0].Num() != 0 {
			} else {
				i := 1
				for ; i+1 < len(t.Clauses); i += 2 {
					if ex.Stack.Pop(1)[0].Num() != 0 {
				if i == len(t.Clauses)-1 && len(t.Clauses) % 2 == 0 {
		case Word:
		case Define:
			v := ex.Variable
			ex.Variable = Num(0)
			ex.Variable = v

func main() {
	ex := &Executor{
		Output: os.Stdout,
		Stack: &Stack{},
		Variable: Num(0),
		Maps: map[string]map[string]Elem{"": make(map[string]Elem)},
		Commands: make(map[string]*Command),
	ex.Map = ex.Maps[""]
	ex.Stack.Executor = ex
		o := opt.NewOptSet()
		lastFileError := errors.New("last file")

		o.Func("f", func(s string) error {
			ex.Progs = append(ex.Progs, &Prog{Filename: s})
			return nil
		o.Func("F", func(s string) error {
			ex.Progs = append(ex.Progs, &Prog{Filename: s})
			return lastFileError

		o.FlagFunc("h", func() error {
		o.Alias("h", "help")

		o.FlagFunc("version", func() error {

		o.BoolFunc("i", func(b bool) error {
			ex.Inplace = b
			return nil

		err := o.Parse(false, os.Args[1:])
		if err != nil && err != lastFileError {
		if len(ex.Progs) > 0 {
			ex.Args = append(o.Args(), o.Leftovers()...)
		} else if len(o.Args()) > 0 {
			ex.Progs = []*Prog{&Prog{Code: o.Args()[0]}}
			ex.Args = append(o.Args()[1:], o.Leftovers()...)
		} else {
		if len(ex.Args) == 0 && ex.Inplace {
			fatal("no input files for -i to overwrite")

	rules := &Rules{}
	defines := make(map[string]Block)
	var recipe []Token
	for _, prog := range ex.Progs {
		if prog.Filename != "" {
			data, err := os.ReadFile(prog.Filename)
			if err != nil {
			prog.Code = string(data)
		parser := &Parser{
			Prog: prog,
			Defines: defines,
			WordFunc: func(word string) func() {
				return wordFunc(ex.Stack, word)
		tokens := parser.Tokenize(parser.Code)
		if debug {
			fmt.Fprintln(os.Stderr, "TOKENS:")
			for _, tok := range tokens {
				fmt.Fprintf(os.Stderr, "%T %v\n", tok, tok)
		i := parser.ParseTop(rules, defines, tokens)
		botDefines := make(map[string]Block)
		j := parser.ParseBottom(rules, botDefines, tokens[i:])
		if i < len(tokens) {
			recipe = append(recipe, parser.Parse(tokens[i:i+j])...)
		for key, val := range botDefines {
			defines[key] = val
	if debug {
		fmt.Fprintln(os.Stderr, "RECIPE:")
		for _, tok := range recipe {
			fmt.Fprintf(os.Stderr, "%T %v\n", tok, tok)

	if ex.Inplace {
		ex.Output = new(bytes.Buffer)
	for _, begin := range rules.Begins {
	if len(recipe) + len(rules.Ends) == 0 {
	args := ex.Args
	if len(args) == 0 {
		args = []string{os.Stdin.Name()}
	for ex.ArgIndex = range args {
		var f *os.File
		if ex.Inplace {
			var err error
			f, err = os.OpenFile(args[ex.ArgIndex], os.O_RDWR, os.ModePerm)
			if err != nil {
		} else {
			var err error
			f, err = os.Open(args[ex.ArgIndex])
			if err != nil {
		sc := bufio.NewScanner(f)
		ex.FileRecordNum = 0
		for sc.Scan() {
			ex.Record = sc.Text()
			if ex.Exit {
		if sc.Err() != nil {
		if ex.Exit || ex.ArgIndex == len(args)-1 {
			ex.Exit = false
			for _, end := range rules.Ends {
			ex.Exit = true
		if ex.Inplace {
			if _, err := f.Seek(0, io.SeekStart); err != nil {
			n, err := io.Copy(f, ex.Output)
			if err != nil {
			if err := f.Truncate(n); err != nil {
		if err := f.Close(); err != nil {
		if ex.Exit {

A  => wordnames.go +93 -0
@@ 1,93 @@
// Code generated by go generate; DO NOT EDIT.

package main

//go:generate sh -c "./wordnames.sed stack.go > wordnames.go"

func wordFunc(stack *Stack, word string) func() {
	switch word {
	case "p": return stack.Print
	case "P": return stack.PrintLine
	case "?": return stack.DebugStack
	case "r": return stack.Record
	case "f": return stack.Field
	case "fc": return stack.FieldCount
	case "n": return stack.RecordNum
	case "N": return stack.FileRecordNum
	case "c": return stack.Count
	case "drop": return stack.Drop
	case "dup": return stack.Dup
	case "swap": return stack.Swap
	case "rot": return stack.Rot
	case "cycle": return stack.Cycle
	case "item": return stack.Item
	case "!": return stack.Store
	case "@": return stack.Fetch
	case "nl": return stack.Newline
	case "tab": return stack.Tab
	case "len": return stack.Len
	case "lower": return stack.Lower
	case "upper": return stack.Upper
	case "ord": return stack.Ord
	case "chr": return stack.Chr
	case "is": return stack.Is
	case "isnt": return stack.Isnt
	case "scale": return stack.Scale
	case ",": return stack.Append
	case "join": return stack.Join
	case "shelljoin": return stack.Shelljoin
	case "~": return stack.Match
	case "!~": return stack.NotMatch
	case "escape": return stack.Escape
	case "split": return stack.Split
	case "extract": return stack.Extract
	case "sub": return stack.Sub
	case "gsub": return stack.Gsub
	case "<": return stack.LessThan
	case "<=": return stack.LessThanOrEqual
	case ">": return stack.GreaterThan
	case ">=": return stack.GreaterThanOrEqual
	case "=": return stack.Equal
	case "!=": return stack.NotEqual
	case "and": return stack.And
	case "or": return stack.Or
	case "+": return stack.Add
	case "-": return stack.Subtract
	case "*": return stack.Multiply
	case "/": return stack.Divide
	case "mod": return stack.Mod
	case "floor": return stack.Floor
	case "pow": return stack.Pow
	case "sqrt": return stack.Sqrt
	case "cos": return stack.Cos
	case "sin": return stack.Sin
	case "atan2": return stack.Atan2
	case "log": return stack.Log
	case "exp": return stack.Exp
	case "rand": return stack.Rand
	case "seed": return stack.Seed
	case "i": return stack.Index
	case "break": return stack.Break
	case "while": return stack.While
	case "iterate": return stack.Iterate
	case "arg": return stack.Arg
	case "argc": return stack.Argc
	case "argi": return stack.Argi
	case "env": return stack.Env
	case "exit": return stack.Exit
	case "map": return stack.Map
	case "set": return stack.Set
	case "+set": return stack.PlusSet
	case "unset": return stack.Unset
	case "get": return stack.Get
	case "keys": return stack.Keys
	case "keyc": return stack.Keyc
	case "run": return stack.Run
	case "command": return stack.Command
	case "send": return stack.Send
	case "receive": return stack.Receive
	case "output": return stack.Output
	case "wait": return stack.Wait
	return nil

A  => wordnames.sed +23 -0
@@ 1,23 @@
#!/bin/sed -f

1 i\
// Code generated by go generate; DO NOT EDIT.\
package main\
//go:generate sh -c "./wordnames.sed stack.go > wordnames.go"\
func wordFunc(stack *Stack, word string) func() {\
	switch word {

$ i\
	return nil\

/^\/\/word/ !d
s/\n[^)]*) / /
s://word ::
s/() {//
s/\(.*\) \(.*\)/\tcase "\1": return stack.\2/