Added support for musl libc.
h3rald h3rald@h3rald.com
Sat, 28 Nov 2020 08:14:25 +0000
1 files changed,
685 insertions(+),
682 deletions(-)
jump to
M
nimline.nim
→
nimline.nim
@@ -1,682 +1,685 @@
-## This module provides a simple, limited but fully-functional line editing library written in pure Nim. -## -## To use this library, you must first initialize a **LineEditor** object using the **initEditor** method, -## and then use the **readLine** method to capture standard input instead of **stdout.readLine**: -## -## .. code-block:: nim -## var ed = initEditor(historyFile = "history.txt") -## while true: -## let str = ed.readLine("-> ") -## echo "You typed: ", str -## -## Optionally, you can also configure custom key bindings for keys and key sequences: -## -## .. code-block:: nim -## KEYMAP["ctrl+k"] = proc(ed: var LineEditor) = -## ed.clearLine() -## -## Additionally, you can also configure a **completionCallback** proc to trigger auto-completion by pressing TAB: -## -## .. code-block:: nim -## ed.completionCallback = proc(ed: LineEditor): seq[string] = -## return @["copy", "list", "delete", "move", "remove"] -## -## **Note** When compared to the readline or linenoise libraries, this module has the following limitations: -## -## * It is only possible to edit one line of text at a time. When using the **readLine** method, it will not be possible to physically go to the next line (this simplifies things a bit...). -## * No UTF8 support, only ASCII characters are supported. -## * No support for colorized output. -## * Only limited support for Emacs keybindings, no support for Vi mode and Vi keybindings. - -import - critbits, - terminal, - deques, - sequtils, - strutils, - std/exitprocs, - os - -addExitProc(resetAttributes) - -when defined(windows): - proc putchr*(c: cint): cint {.discardable, header: "<conio.h>", importc: "_putch".} - ## Prints an ASCII character to stdout. - proc getchr*(): cint {.header: "<conio.h>", importc: "_getch".} - ## Retrieves an ASCII character from stdin. -else: - proc putchr*(c: cint) = - ## Prints an ASCII character to stdout. - stdout.write(c.chr) - - proc getchr*(): cint = - ## Retrieves an ASCII character from stdin. - return getch().ord.cint - -# Types - -type - Key* = int ## The ASCII code of a keyboard key. - KeySeq* = seq[Key] ## A sequence of one or more Keys. - KeyCallback* = proc(ed: var LineEditor) ## A proc that can be bound to a key or a key sequence to access line editing functionalities. - LineError* = ref Exception ## A generic nimline error. - LineEditorError* = ref Exception ## An error occured in the LineEditor. - LineEditorMode* = enum ## The *mode* a LineEditor operates in (insert or replace). - mdInsert - mdReplace - Line* = object ## An object representing a line of text. - text: string - position: int - LineHistory* = object ## An object representing the history of all commands typed in a LineEditor. - file: string - tainted: bool - position: int - queue: Deque[string] - max: int - LineEditor* = object ## An object representing a line editor, used to process text typed in the terminal. - completionCallback*: proc(ed: LineEditor): seq[string] - history: LineHistory - line: Line - mode: LineEditorMode - -# Internal Methods - -proc empty(line: Line): bool = - return line.text.len <= 0 - -proc full(line: Line): bool = - return line.position >= line.text.len - -proc first(line: Line): int = - if line.empty: - raise LineError(msg: "Line is empty!") - return 0 - -proc last(line: Line): int = - if line.empty: - raise LineError(msg: "Line is empty!") - return line.text.len-1 - -proc fromStart(line: Line): string = - if line.empty: - return "" - return line.text[line.first..line.position-1] - -proc toEnd(line: Line): string = - if line.empty: - return "" - return line.text[line.position..line.last] - -proc back*(ed: var LineEditor, n=1) = - ## Move the cursor back by **n** characters on the current line (unless the beginning of the line is reached). - if ed.line.position <= 0: - return - stdout.cursorBackward(n) - ed.line.position = ed.line.position - n - -proc forward*(ed: var LineEditor, n=1) = - ## Move the cursor forward by **n** characters on the current line (unless the beginning of the line is reached). - if ed.line.full: - return - stdout.cursorForward(n) - ed.line.position += n - -proc `[]`( q: Deque[string], pos: int): string = - var c = 0 - for e in q.items: - if c == pos: - result = e - break - c.inc - -proc `[]=`( q: var Deque[string], pos: int, s: string) = - var c = 0 - for e in q.mitems: - if c == pos: - e = s - break - c.inc - -proc add(h: var LineHistory, s: string, force=false) = - if s == "" and not force: - return - if h.queue.len >= h.max: - discard h.queue.popFirst - if h.tainted: - h.queue[h.queue.len-1] = s - else: - h.queue.addLast s - -proc previous(h: var LineHistory): string = - if h.queue.len == 0 or h.position <= 0: - return "" - h.position.dec - result = h.queue[h.position] - -proc next(h: var LineHistory): string = - if h.queue.len == 0 or h.position >= h.queue.len-1: - return "" - h.position.inc - result = h.queue[h.position] - -# Public API - -proc deletePrevious*(ed: var LineEditor) = - ## Move the cursor to the left by one character (unless at the beginning of the line) and delete the existing character, if any. - if ed.line.position <= 0: - return - if not ed.line.empty: - if ed.line.full: - stdout.cursorBackward - putchr(32) - stdout.cursorBackward - ed.line.position.dec - ed.line.text = ed.line.text[0..ed.line.last-1] - else: - let rest = ed.line.toEnd & " " - ed.back - for i in rest: - putchr i.ord.cint - ed.line.text = ed.line.fromStart & ed.line.text[ed.line.position+1..ed.line.last] - stdout.cursorBackward(rest.len) - -proc deleteNext*(ed: var LineEditor) = - ## Move the cursor to the right by one character (unless at the end of the line) and delete the existing character, if any. - if not ed.line.empty: - if not ed.line.full: - let rest = ed.line.toEnd[1..^1] & " " - for c in rest: - putchr c.ord.cint - stdout.cursorBackward(rest.len) - ed.line.text = ed.line.fromStart & ed.line.toEnd[1..^1] - -proc printChar*(ed: var LineEditor, c: int) = - ## Prints the character **c** to the current line. If in the middle of the line, the following characters are shifted right or replaced depending on the editor mode. - if ed.line.full: - putchr(c.cint) - ed.line.text &= c.chr - ed.line.position += 1 - else: - if ed.mode == mdInsert: - putchr(c.cint) - let rest = ed.line.toEnd - ed.line.text.insert($c.chr, ed.line.position) - ed.line.position += 1 - for j in rest: - putchr(j.ord.cint) - ed.line.position += 1 - ed.back(rest.len) - else: - putchr(c.cint) - ed.line.text[ed.line.position] = c.chr - ed.line.position += 1 - -proc changeLine*(ed: var LineEditor, s: string) = - ## Replaces the contents of the current line with the string **s**. - let text = ed.line.text - let diff = text.len - s.len - let position = ed.line.position - if position > 0: - stdout.cursorBackward(position) - for c in s: - putchr(c.ord.cint) - ed.line.position = s.len - ed.line.text = s - if diff > 0: - for i in 0.countup(diff-1): - putchr(32) - stdout.cursorBackward(diff) - -proc addToLineAtPosition(ed: var LineEditor, s: string) = - for c in s: - ed.printChar(c.ord.cint) - -proc clearLine*(ed: var LineEditor) = - ## Clears the contents of the current line and reset the cursor position to the beginning of the line. - stdout.cursorBackward(ed.line.position+1) - for i in ed.line.text: - putchr(32) - putchr(32) - putchr(32) - stdout.cursorBackward(ed.line.text.len+1) - ed.line.position = 0 - ed.line.text = "" - -proc goToStart*(ed: var LineEditor) = - ## Move the cursor to the beginning of the line. - if ed.line.position <= 0: - return - try: - stdout.cursorBackward(ed.line.position) - ed.line.position = 0 - except: - discard - -proc goToEnd*(ed: var LineEditor) = - ## Move the cursor to the end of the line. - if ed.line.full: - return - let diff = ed.line.text.len - ed.line.position - stdout.cursorForward(diff) - ed.line.position = ed.line.text.len - -proc historyInit*(size = 256, file: string = ""): LineHistory = - ## Creates a new **LineHistory** object with the specified **size** and **file**. - result.file = file - result.queue = initDeque[string](size) - result.position = 0 - result.tainted = false - result.max = size - if file == "": - return - if result.file.fileExists: - let lines = result.file.readFile.split("\n") - for line in lines: - if line != "": - result.add line - result.position = lines.len - else: - result.file.writeFile("") - -proc historyAdd*(ed: var LineEditor, force = false) = - ## Adds the current editor line to the history. If **force** is set to **true**, the line will be added even if it's blank. - ed.history.add ed.line.text, force - if ed.history.file == "": - return - ed.history.file.writeFile(toSeq(ed.history.queue.items).join("\n")) - -proc historyPrevious*(ed: var LineEditor) = - ## Replaces the contents of the current line with the previous line stored in the history (if any). - ## The current line will be added to the history and the hisory will be marked as *tainted*. - let s = ed.history.previous - if s == "": - return - let pos = ed.history.position - var current: int - if ed.history.tainted: - current = ed.history.queue.len-2 - else: - current = ed.history.queue.len-1 - if pos == current and ed.history.queue[current] != ed.line.text: - ed.historyAdd(force = true) - ed.history.tainted = true - if s != "": - ed.changeLine(s) - -proc historyNext*(ed: var LineEditor) = - ## Replaces the contents of the current line with the following line stored in the history (if any). - let s = ed.history.next - if s == "": - return - ed.changeLine(s) - -proc historyFlush*(ed: var LineEditor) = - ## If there is at least one entry in the history, it sets the position of the cursor to the last element and sets the **tainted** flag to **false**. - if ed.history.queue.len > 0: - ed.history.position = ed.history.queue.len - ed.history.tainted = false - -proc completeLine*(ed: var LineEditor): int = - ## If a **completionCallback** proc has been specified for the current editor, attempts to auto-complete the current line by running **completionProc** - ## to return a list of possible values. It is possible to cycle through the matches by pressing the same key that triggered this proc. - ## - ## The matches provided will be filtered based on the contents of the line when this proc was first triggered. If a match starts with the contents of the line, it - ## will be displayed. - ## - ## The following is a real-world example of a **completionCallback** used to complete the last word on the line with valid file paths. - ## - ## .. code-block:: nim - ## import sequtils, strutils, ospath - ## - ## ed.completionCallback = proc(ed: LineEditor): seq[string] = - ## var words = ed.lineText.split(" ") - ## var word: string - ## if words.len == 0: - ## word = ed.lineText - ## else: - ## word = words[words.len-1] - ## var f = word[1..^1] - ## if f == "": - ## f = getCurrentDir().replace("\\", "/") - ## return toSeq(walkDir(f, true)) - ## .mapIt("\"$1" % it.path.replace("\\", "/")) - ## elif f.dirExists: - ## f = f.replace("\\", "/") - ## if f[f.len-1] != '/': - ## f = f & "/" - ## return toSeq(walkDir(f, true)) - ## .mapIt("\"$1$2" % [f, it.path.replace("\\", "/")]) - ## else: - ## var dir: string - ## if f.contains("/") or dir.contains("\\"): - ## dir = f.parentDir - ## let file = f.extractFileName - ## return toSeq(walkDir(dir, true)) - ## .filterIt(it.path.toLowerAscii.startsWith(file.toLowerAscii)) - ## .mapIt("\"$1/$2" % [dir, it.path.replace("\\", "/")]) - ## else: - ## dir = getCurrentDir() - ## return toSeq(walkDir(dir, true)) - ## .filterIt(it.path.toLowerAscii.startsWith(f.toLowerAscii)) - ## .mapIt("\"$1" % [it.path.replace("\\", "/")]) - ## - if ed.completionCallback.isNil: - return - let compl = ed.completionCallback(ed) - let position = ed.line.position - let words = ed.line.fromStart.split(" ") - var word: string - if words.len > 0: - word = words[words.len-1] - else: - word = ed.line.fromStart - var matches = compl.filterIt(it.toLowerAscii.startsWith(word.toLowerAscii)) - if ed.line.fromStart.len > 0 and matches.len > 0: - for i in 0..word.len-1: - ed.deletePrevious - var n = 0 - if matches.len > 0: - ed.addToLineAtPosition(matches[0]) - else: - return -1 - var ch = getchr() - while ch == 9: - n.inc - if n < matches.len: - let diff = ed.line.position - position - for i in 0.countup(diff-1 + word.len): - ed.deletePrevious - ed.addToLineAtPosition(matches[n]) - ch = getchr() - else: - n = -1 - return ch - -proc lineText*(ed: LineEditor): string = - ## Returns the contents of the current line. - return ed.line.text - -proc initEditor*(mode = mdInsert, historySize = 256, historyFile: string = ""): LineEditor = - ## Creates a **LineEditor** object. - result.mode = mode - result.history = historyInit(historySize, historyFile) - -# Character sets -const - CTRL* = {0 .. 31} ## Control characters. - DIGIT* = {48 .. 57} ## Digits. - LETTER* = {65 .. 122} ## Letters. - UPPERLETTER* = {65 .. 90} ## Uppercase letters. - LOWERLETTER* = {97 .. 122} ## Lowercase letters. - PRINTABLE* = {32 .. 126} ## Printable characters. -when defined(windows): - const - ESCAPES* = {0, 22, 224} ## Escape characters. -else: - const - ESCAPES* = {27} ## Escape characters. - -# Key Names -var KEYNAMES*: array[0..31, string] ## The following strings can be used in keymaps instead of the correspinding ASCII codes: -## -## .. code-block:: nim -## KEYNAMES[1] = "ctrl+a" -## KEYNAMES[2] = "ctrl+b" -## KEYNAMES[3] = "ctrl+c" -## KEYNAMES[4] = "ctrl+d" -## KEYNAMES[5] = "ctrl+e" -## KEYNAMES[6] = "ctrl+f" -## KEYNAMES[7] = "ctrl+g" -## KEYNAMES[8] = "ctrl+h" -## KEYNAMES[9] = "ctrl+i" -## KEYNAMES[9] = "tab" -## KEYNAMES[10] = "ctrl+j" -## KEYNAMES[11] = "ctrl+k" -## KEYNAMES[12] = "ctrl+l" -## KEYNAMES[13] = "ctrl+m" -## KEYNAMES[14] = "ctrl+n" -## KEYNAMES[15] = "ctrl+o" -## KEYNAMES[16] = "ctrl+p" -## KEYNAMES[17] = "ctrl+q" -## KEYNAMES[18] = "ctrl+r" -## KEYNAMES[19] = "ctrl+s" -## KEYNAMES[20] = "ctrl+t" -## KEYNAMES[21] = "ctrl+u" -## KEYNAMES[22] = "ctrl+v" -## KEYNAMES[23] = "ctrl+w" -## KEYNAMES[24] = "ctrl+x" -## KEYNAMES[25] = "ctrl+y" -## KEYNAMES[26] = "ctrl+z" - -KEYNAMES[1] = "ctrl+a" -KEYNAMES[2] = "ctrl+b" -KEYNAMES[3] = "ctrl+c" -KEYNAMES[4] = "ctrl+d" -KEYNAMES[5] = "ctrl+e" -KEYNAMES[6] = "ctrl+f" -KEYNAMES[7] = "ctrl+g" -KEYNAMES[8] = "ctrl+h" -KEYNAMES[9] = "ctrl+i" -KEYNAMES[9] = "tab" -KEYNAMES[10] = "ctrl+j" -KEYNAMES[11] = "ctrl+k" -KEYNAMES[12] = "ctrl+l" -KEYNAMES[13] = "ctrl+m" -KEYNAMES[14] = "ctrl+n" -KEYNAMES[15] = "ctrl+o" -KEYNAMES[16] = "ctrl+p" -KEYNAMES[17] = "ctrl+q" -KEYNAMES[18] = "ctrl+r" -KEYNAMES[19] = "ctrl+s" -KEYNAMES[20] = "ctrl+t" -KEYNAMES[21] = "ctrl+u" -KEYNAMES[22] = "ctrl+v" -KEYNAMES[23] = "ctrl+w" -KEYNAMES[24] = "ctrl+x" -KEYNAMES[25] = "ctrl+y" -KEYNAMES[26] = "ctrl+z" - -# Key Sequences -var KEYSEQS*: CritBitTree[KeySeq] ## The following key sequences are defined and are used internally by **LineEditor**: -## -## .. code-block:: nim -## KEYSEQS["up"] = @[27, 91, 65] # Windows: @[224, 72] -## KEYSEQS["down"] = @[27, 91, 66] # Windows: @[224, 80] -## KEYSEQS["right"] = @[27, 91, 67] # Windows: @[224, 77] -## KEYSEQS["left"] = @[27, 91, 68] # Windows: @[224, 75] -## KEYSEQS["home"] = @[27, 91, 72] # Windows: @[224, 71] -## KEYSEQS["end"] = @[27, 91, 70] # Windows: @[224, 79] -## KEYSEQS["insert"] = @[27, 91, 50, 126] # Windows: @[224, 82] -## KEYSEQS["delete"] = @[27, 91, 51, 126] # Windows: @[224, 83] - -when defined(windows): - KEYSEQS["up"] = @[224, 72] - KEYSEQS["down"] = @[224, 80] - KEYSEQS["right"] = @[224, 77] - KEYSEQS["left"] = @[224, 75] - KEYSEQS["home"] = @[224, 71] - KEYSEQS["end"] = @[224, 79] - KEYSEQS["insert"] = @[224, 82] - KEYSEQS["delete"] = @[224, 83] -else: - KEYSEQS["up"] = @[27, 91, 65] - KEYSEQS["down"] = @[27, 91, 66] - KEYSEQS["right"] = @[27, 91, 67] - KEYSEQS["left"] = @[27, 91, 68] - KEYSEQS["home"] = @[27, 91, 72] - KEYSEQS["end"] = @[27, 91, 70] - KEYSEQS["insert"] = @[27, 91, 50, 126] - KEYSEQS["delete"] = @[27, 91, 51, 126] - -# Key Mappings -var KEYMAP*: CritBitTree[KeyCallBack] ## The following key mappings are configured by default: -## -## * backspace: **deletePrevious** -## * delete: **deleteNext** -## * insert: *toggle editor mode* -## * down: **historyNext** -## * up: **historyPrevious** -## * ctrl+n: **historyNext** -## * ctrl+p: **historyPrevious** -## * left: **back** -## * right: **forward** -## * ctrl+b: **back** -## * ctrl+f: **forward** -## * ctrl+c: *quits the program* -## * ctrl+d: *quits the program* -## * ctrl+u: **clearLine** -## * ctrl+a: **goToStart** -## * ctrl+e: **goToEnd** -## * home: **goToStart** -## * end: **goToEnd** - -KEYMAP["backspace"] = proc(ed: var LineEditor) = - ed.deletePrevious() -KEYMAP["delete"] = proc(ed: var LineEditor) = - ed.deleteNext() -KEYMAP["insert"] = proc(ed: var LineEditor) = - if ed.mode == mdInsert: - ed.mode = mdReplace - else: - ed.mode = mdInsert -KEYMAP["down"] = proc(ed: var LineEditor) = - ed.historyNext() -KEYMAP["up"] = proc(ed: var LineEditor) = - ed.historyPrevious() -KEYMAP["ctrl+n"] = proc(ed: var LineEditor) = - ed.historyNext() -KEYMAP["ctrl+p"] = proc(ed: var LineEditor) = - ed.historyPrevious() -KEYMAP["left"] = proc(ed: var LineEditor) = - ed.back() -KEYMAP["right"] = proc(ed: var LineEditor) = - ed.forward() -KEYMAP["ctrl+b"] = proc(ed: var LineEditor) = - ed.back() -KEYMAP["ctrl+f"] = proc(ed: var LineEditor) = - ed.forward() -KEYMAP["ctrl+c"] = proc(ed: var LineEditor) = - quit(0) -KEYMAP["ctrl+d"] = proc(ed: var LineEditor) = - quit(0) -KEYMAP["ctrl+u"] = proc(ed: var LineEditor) = - ed.clearLine() -KEYMAP["ctrl+a"] = proc(ed: var LineEditor) = - ed.goToStart() -KEYMAP["ctrl+e"] = proc(ed: var LineEditor) = - ed.goToEnd() -KEYMAP["home"] = proc(ed: var LineEditor) = - ed.goToStart() -KEYMAP["end"] = proc(ed: var LineEditor) = - ed.goToEnd() - -proc readLine*(ed: var LineEditor, prompt="", hidechars = false): string = - ## High-level proc to be used instead of **stdin.readLine** to read a line from standard input using the specified **LineEditor** object. - ## - ## Note that: - ## * **prompt** is a string (that *cannot* contain escape codes, so it cannot be colored) that will be prepended at the start of the line and - ## not included in the contents of the line itself. - ## * If **hidechars** is set to **true**, asterisks will be printed to stdout instead of the characters entered by the user. - stdout.write(prompt) - ed.line = Line(text: "", position: 0) - var c = -1 # Used to manage completions - var esc = false - while true: - var c1: int - if c > 0: - c1 = c - c = -1 - else: - c1 = getchr() - if esc: - esc = false - continue - elif c1 in {10, 13}: - stdout.write("\n") - ed.historyAdd() - ed.historyFlush() - return ed.line.text - elif c1 in {8, 127}: - KEYMAP["backspace"](ed) - elif c1 in PRINTABLE: - if hidechars: - putchr('*'.ord.cint) - ed.line.text &= c1.chr - ed.line.position.inc - else: - ed.printChar(c1) - elif c1 == 9: # TAB - c = ed.completeLine() - elif c1 in ESCAPES: - var s = newSeq[Key](0) - s.add(c1) - let c2 = getchr() - s.add(c2) - if s == KEYSEQS["left"]: - KEYMAP["left"](ed) - elif s == KEYSEQS["right"]: - KEYMAP["right"](ed) - elif s == KEYSEQS["up"]: - KEYMAP["up"](ed) - elif s == KEYSEQS["down"]: - KEYMAP["down"](ed) - elif s == KEYSEQS["home"]: - KEYMAP["home"](ed) - elif s == KEYSEQS["end"]: - KEYMAP["end"](ed) - elif s == KEYSEQS["delete"]: - KEYMAP["delete"](ed) - elif s == KEYSEQS["insert"]: - KEYMAP["insert"](ed) - elif c2 == 91: - let c3 = getchr() - s.add(c3) - if s == KEYSEQS["right"]: - KEYMAP["right"](ed) - elif s == KEYSEQS["left"]: - KEYMAP["left"](ed) - elif s == KEYSEQS["up"]: - KEYMAP["up"](ed) - elif s == KEYSEQS["down"]: - KEYMAP["down"](ed) - elif s == KEYSEQS["home"]: - KEYMAP["home"](ed) - elif s == KEYSEQS["end"]: - KEYMAP["end"](ed) - elif c3 in {50, 51}: - let c4 = getchr() - s.add(c4) - if c4 == 126 and c3 == 50: - KEYMAP["insert"](ed) - elif c4 == 126 and c3 == 51: - KEYMAP["delete"](ed) - elif c1 in CTRL and KEYMAP.hasKey(KEYNAMES[c1]): - KEYMAP[KEYNAMES[c1]](ed) - else: - # Assuming unhandled two-values escape sequence; do nothing. - if esc: - esc = false - continue - else: - esc = true - continue - -proc password*(ed: var LineEditor, prompt=""): string = - ## Convenience method to use instead of **readLine** to hide the characters inputed by the user. - return ed.readLine(prompt, true) - -when isMainModule: - #proc testChar() = - # while true: - # let a = getchr() - # echo "\n->", a - # if a == 3: - # quit(0) - # - #testChar() - proc testLineEditor() = - var ed = initEditor(historyFile = "") - while true: - echo "---", ed.readLine("-> "), "---" - - testLineEditor() +## This module provides a simple, limited but fully-functional line editing library written in pure Nim. +## +## To use this library, you must first initialize a **LineEditor** object using the **initEditor** method, +## and then use the **readLine** method to capture standard input instead of **stdout.readLine**: +## +## .. code-block:: nim +## var ed = initEditor(historyFile = "history.txt") +## while true: +## let str = ed.readLine("-> ") +## echo "You typed: ", str +## +## Optionally, you can also configure custom key bindings for keys and key sequences: +## +## .. code-block:: nim +## KEYMAP["ctrl+k"] = proc(ed: var LineEditor) = +## ed.clearLine() +## +## Additionally, you can also configure a **completionCallback** proc to trigger auto-completion by pressing TAB: +## +## .. code-block:: nim +## ed.completionCallback = proc(ed: LineEditor): seq[string] = +## return @["copy", "list", "delete", "move", "remove"] +## +## **Note** When compared to the readline or linenoise libraries, this module has the following limitations: +## +## * It is only possible to edit one line of text at a time. When using the **readLine** method, it will not be possible to physically go to the next line (this simplifies things a bit...). +## * No UTF8 support, only ASCII characters are supported. +## * No support for colorized output. +## * Only limited support for Emacs keybindings, no support for Vi mode and Vi keybindings. + +import + critbits, + terminal, + deques, + sequtils, + strutils, + std/exitprocs, + os + +addExitProc(resetAttributes) + +when defined(windows): + proc putchr*(c: cint): cint {.discardable, header: "<conio.h>", importc: "_putch".} + ## Prints an ASCII character to stdout. + proc getchr*(): cint {.header: "<conio.h>", importc: "_getch".} + ## Retrieves an ASCII character from stdin. +else: + proc putchr*(c: cint) {.header: "stdio.h", importc: "putchar"} = + ## Prints an ASCII character to stdout. + stdout.write(c.chr) + stdout.flushFile() + + proc getchr*(): cint = + ## Retrieves an ASCII character from stdin. + stdout.flushFile() + return getch().ord.cint + +# Types + +type + Key* = int ## The ASCII code of a keyboard key. + KeySeq* = seq[Key] ## A sequence of one or more Keys. + KeyCallback* = proc(ed: var LineEditor) ## A proc that can be bound to a key or a key sequence to access line editing functionalities. + LineError* = ref Exception ## A generic nimline error. + LineEditorError* = ref Exception ## An error occured in the LineEditor. + LineEditorMode* = enum ## The *mode* a LineEditor operates in (insert or replace). + mdInsert + mdReplace + Line* = object ## An object representing a line of text. + text: string + position: int + LineHistory* = object ## An object representing the history of all commands typed in a LineEditor. + file: string + tainted: bool + position: int + queue: Deque[string] + max: int + LineEditor* = object ## An object representing a line editor, used to process text typed in the terminal. + completionCallback*: proc(ed: LineEditor): seq[string] + history: LineHistory + line: Line + mode: LineEditorMode + +# Internal Methods + +proc empty(line: Line): bool = + return line.text.len <= 0 + +proc full(line: Line): bool = + return line.position >= line.text.len + +proc first(line: Line): int = + if line.empty: + raise LineError(msg: "Line is empty!") + return 0 + +proc last(line: Line): int = + if line.empty: + raise LineError(msg: "Line is empty!") + return line.text.len-1 + +proc fromStart(line: Line): string = + if line.empty: + return "" + return line.text[line.first..line.position-1] + +proc toEnd(line: Line): string = + if line.empty: + return "" + return line.text[line.position..line.last] + +proc back*(ed: var LineEditor, n=1) = + ## Move the cursor back by **n** characters on the current line (unless the beginning of the line is reached). + if ed.line.position <= 0: + return + stdout.cursorBackward(n) + ed.line.position = ed.line.position - n + +proc forward*(ed: var LineEditor, n=1) = + ## Move the cursor forward by **n** characters on the current line (unless the beginning of the line is reached). + if ed.line.full: + return + stdout.cursorForward(n) + ed.line.position += n + +proc `[]`( q: Deque[string], pos: int): string = + var c = 0 + for e in q.items: + if c == pos: + result = e + break + c.inc + +proc `[]=`( q: var Deque[string], pos: int, s: string) = + var c = 0 + for e in q.mitems: + if c == pos: + e = s + break + c.inc + +proc add(h: var LineHistory, s: string, force=false) = + if s == "" and not force: + return + if h.queue.len >= h.max: + discard h.queue.popFirst + if h.tainted: + h.queue[h.queue.len-1] = s + else: + h.queue.addLast s + +proc previous(h: var LineHistory): string = + if h.queue.len == 0 or h.position <= 0: + return "" + h.position.dec + result = h.queue[h.position] + +proc next(h: var LineHistory): string = + if h.queue.len == 0 or h.position >= h.queue.len-1: + return "" + h.position.inc + result = h.queue[h.position] + +# Public API + +proc deletePrevious*(ed: var LineEditor) = + ## Move the cursor to the left by one character (unless at the beginning of the line) and delete the existing character, if any. + if ed.line.position <= 0: + return + if not ed.line.empty: + if ed.line.full: + stdout.cursorBackward + putchr(32) + stdout.cursorBackward + ed.line.position.dec + ed.line.text = ed.line.text[0..ed.line.last-1] + else: + let rest = ed.line.toEnd & " " + ed.back + for i in rest: + putchr i.ord.cint + ed.line.text = ed.line.fromStart & ed.line.text[ed.line.position+1..ed.line.last] + stdout.cursorBackward(rest.len) + +proc deleteNext*(ed: var LineEditor) = + ## Move the cursor to the right by one character (unless at the end of the line) and delete the existing character, if any. + if not ed.line.empty: + if not ed.line.full: + let rest = ed.line.toEnd[1..^1] & " " + for c in rest: + putchr c.ord.cint + stdout.cursorBackward(rest.len) + ed.line.text = ed.line.fromStart & ed.line.toEnd[1..^1] + +proc printChar*(ed: var LineEditor, c: int) = + ## Prints the character **c** to the current line. If in the middle of the line, the following characters are shifted right or replaced depending on the editor mode. + if ed.line.full: + putchr(c.cint) + ed.line.text &= c.chr + ed.line.position += 1 + else: + if ed.mode == mdInsert: + putchr(c.cint) + let rest = ed.line.toEnd + ed.line.text.insert($c.chr, ed.line.position) + ed.line.position += 1 + for j in rest: + putchr(j.ord.cint) + ed.line.position += 1 + ed.back(rest.len) + else: + putchr(c.cint) + ed.line.text[ed.line.position] = c.chr + ed.line.position += 1 + +proc changeLine*(ed: var LineEditor, s: string) = + ## Replaces the contents of the current line with the string **s**. + let text = ed.line.text + let diff = text.len - s.len + let position = ed.line.position + if position > 0: + stdout.cursorBackward(position) + for c in s: + putchr(c.ord.cint) + ed.line.position = s.len + ed.line.text = s + if diff > 0: + for i in 0.countup(diff-1): + putchr(32) + stdout.cursorBackward(diff) + +proc addToLineAtPosition(ed: var LineEditor, s: string) = + for c in s: + ed.printChar(c.ord.cint) + +proc clearLine*(ed: var LineEditor) = + ## Clears the contents of the current line and reset the cursor position to the beginning of the line. + stdout.cursorBackward(ed.line.position+1) + for i in ed.line.text: + putchr(32) + putchr(32) + putchr(32) + stdout.cursorBackward(ed.line.text.len+1) + ed.line.position = 0 + ed.line.text = "" + +proc goToStart*(ed: var LineEditor) = + ## Move the cursor to the beginning of the line. + if ed.line.position <= 0: + return + try: + stdout.cursorBackward(ed.line.position) + ed.line.position = 0 + except: + discard + +proc goToEnd*(ed: var LineEditor) = + ## Move the cursor to the end of the line. + if ed.line.full: + return + let diff = ed.line.text.len - ed.line.position + stdout.cursorForward(diff) + ed.line.position = ed.line.text.len + +proc historyInit*(size = 256, file: string = ""): LineHistory = + ## Creates a new **LineHistory** object with the specified **size** and **file**. + result.file = file + result.queue = initDeque[string](size) + result.position = 0 + result.tainted = false + result.max = size + if file == "": + return + if result.file.fileExists: + let lines = result.file.readFile.split("\n") + for line in lines: + if line != "": + result.add line + result.position = lines.len + else: + result.file.writeFile("") + +proc historyAdd*(ed: var LineEditor, force = false) = + ## Adds the current editor line to the history. If **force** is set to **true**, the line will be added even if it's blank. + ed.history.add ed.line.text, force + if ed.history.file == "": + return + ed.history.file.writeFile(toSeq(ed.history.queue.items).join("\n")) + +proc historyPrevious*(ed: var LineEditor) = + ## Replaces the contents of the current line with the previous line stored in the history (if any). + ## The current line will be added to the history and the hisory will be marked as *tainted*. + let s = ed.history.previous + if s == "": + return + let pos = ed.history.position + var current: int + if ed.history.tainted: + current = ed.history.queue.len-2 + else: + current = ed.history.queue.len-1 + if pos == current and ed.history.queue[current] != ed.line.text: + ed.historyAdd(force = true) + ed.history.tainted = true + if s != "": + ed.changeLine(s) + +proc historyNext*(ed: var LineEditor) = + ## Replaces the contents of the current line with the following line stored in the history (if any). + let s = ed.history.next + if s == "": + return + ed.changeLine(s) + +proc historyFlush*(ed: var LineEditor) = + ## If there is at least one entry in the history, it sets the position of the cursor to the last element and sets the **tainted** flag to **false**. + if ed.history.queue.len > 0: + ed.history.position = ed.history.queue.len + ed.history.tainted = false + +proc completeLine*(ed: var LineEditor): int = + ## If a **completionCallback** proc has been specified for the current editor, attempts to auto-complete the current line by running **completionProc** + ## to return a list of possible values. It is possible to cycle through the matches by pressing the same key that triggered this proc. + ## + ## The matches provided will be filtered based on the contents of the line when this proc was first triggered. If a match starts with the contents of the line, it + ## will be displayed. + ## + ## The following is a real-world example of a **completionCallback** used to complete the last word on the line with valid file paths. + ## + ## .. code-block:: nim + ## import sequtils, strutils, ospath + ## + ## ed.completionCallback = proc(ed: LineEditor): seq[string] = + ## var words = ed.lineText.split(" ") + ## var word: string + ## if words.len == 0: + ## word = ed.lineText + ## else: + ## word = words[words.len-1] + ## var f = word[1..^1] + ## if f == "": + ## f = getCurrentDir().replace("\\", "/") + ## return toSeq(walkDir(f, true)) + ## .mapIt("\"$1" % it.path.replace("\\", "/")) + ## elif f.dirExists: + ## f = f.replace("\\", "/") + ## if f[f.len-1] != '/': + ## f = f & "/" + ## return toSeq(walkDir(f, true)) + ## .mapIt("\"$1$2" % [f, it.path.replace("\\", "/")]) + ## else: + ## var dir: string + ## if f.contains("/") or dir.contains("\\"): + ## dir = f.parentDir + ## let file = f.extractFileName + ## return toSeq(walkDir(dir, true)) + ## .filterIt(it.path.toLowerAscii.startsWith(file.toLowerAscii)) + ## .mapIt("\"$1/$2" % [dir, it.path.replace("\\", "/")]) + ## else: + ## dir = getCurrentDir() + ## return toSeq(walkDir(dir, true)) + ## .filterIt(it.path.toLowerAscii.startsWith(f.toLowerAscii)) + ## .mapIt("\"$1" % [it.path.replace("\\", "/")]) + ## + if ed.completionCallback.isNil: + return + let compl = ed.completionCallback(ed) + let position = ed.line.position + let words = ed.line.fromStart.split(" ") + var word: string + if words.len > 0: + word = words[words.len-1] + else: + word = ed.line.fromStart + var matches = compl.filterIt(it.toLowerAscii.startsWith(word.toLowerAscii)) + if ed.line.fromStart.len > 0 and matches.len > 0: + for i in 0..word.len-1: + ed.deletePrevious + var n = 0 + if matches.len > 0: + ed.addToLineAtPosition(matches[0]) + else: + return -1 + var ch = getchr() + while ch == 9: + n.inc + if n < matches.len: + let diff = ed.line.position - position + for i in 0.countup(diff-1 + word.len): + ed.deletePrevious + ed.addToLineAtPosition(matches[n]) + ch = getchr() + else: + n = -1 + return ch + +proc lineText*(ed: LineEditor): string = + ## Returns the contents of the current line. + return ed.line.text + +proc initEditor*(mode = mdInsert, historySize = 256, historyFile: string = ""): LineEditor = + ## Creates a **LineEditor** object. + result.mode = mode + result.history = historyInit(historySize, historyFile) + +# Character sets +const + CTRL* = {0 .. 31} ## Control characters. + DIGIT* = {48 .. 57} ## Digits. + LETTER* = {65 .. 122} ## Letters. + UPPERLETTER* = {65 .. 90} ## Uppercase letters. + LOWERLETTER* = {97 .. 122} ## Lowercase letters. + PRINTABLE* = {32 .. 126} ## Printable characters. +when defined(windows): + const + ESCAPES* = {0, 22, 224} ## Escape characters. +else: + const + ESCAPES* = {27} ## Escape characters. + +# Key Names +var KEYNAMES*: array[0..31, string] ## The following strings can be used in keymaps instead of the correspinding ASCII codes: +## +## .. code-block:: nim +## KEYNAMES[1] = "ctrl+a" +## KEYNAMES[2] = "ctrl+b" +## KEYNAMES[3] = "ctrl+c" +## KEYNAMES[4] = "ctrl+d" +## KEYNAMES[5] = "ctrl+e" +## KEYNAMES[6] = "ctrl+f" +## KEYNAMES[7] = "ctrl+g" +## KEYNAMES[8] = "ctrl+h" +## KEYNAMES[9] = "ctrl+i" +## KEYNAMES[9] = "tab" +## KEYNAMES[10] = "ctrl+j" +## KEYNAMES[11] = "ctrl+k" +## KEYNAMES[12] = "ctrl+l" +## KEYNAMES[13] = "ctrl+m" +## KEYNAMES[14] = "ctrl+n" +## KEYNAMES[15] = "ctrl+o" +## KEYNAMES[16] = "ctrl+p" +## KEYNAMES[17] = "ctrl+q" +## KEYNAMES[18] = "ctrl+r" +## KEYNAMES[19] = "ctrl+s" +## KEYNAMES[20] = "ctrl+t" +## KEYNAMES[21] = "ctrl+u" +## KEYNAMES[22] = "ctrl+v" +## KEYNAMES[23] = "ctrl+w" +## KEYNAMES[24] = "ctrl+x" +## KEYNAMES[25] = "ctrl+y" +## KEYNAMES[26] = "ctrl+z" + +KEYNAMES[1] = "ctrl+a" +KEYNAMES[2] = "ctrl+b" +KEYNAMES[3] = "ctrl+c" +KEYNAMES[4] = "ctrl+d" +KEYNAMES[5] = "ctrl+e" +KEYNAMES[6] = "ctrl+f" +KEYNAMES[7] = "ctrl+g" +KEYNAMES[8] = "ctrl+h" +KEYNAMES[9] = "ctrl+i" +KEYNAMES[9] = "tab" +KEYNAMES[10] = "ctrl+j" +KEYNAMES[11] = "ctrl+k" +KEYNAMES[12] = "ctrl+l" +KEYNAMES[13] = "ctrl+m" +KEYNAMES[14] = "ctrl+n" +KEYNAMES[15] = "ctrl+o" +KEYNAMES[16] = "ctrl+p" +KEYNAMES[17] = "ctrl+q" +KEYNAMES[18] = "ctrl+r" +KEYNAMES[19] = "ctrl+s" +KEYNAMES[20] = "ctrl+t" +KEYNAMES[21] = "ctrl+u" +KEYNAMES[22] = "ctrl+v" +KEYNAMES[23] = "ctrl+w" +KEYNAMES[24] = "ctrl+x" +KEYNAMES[25] = "ctrl+y" +KEYNAMES[26] = "ctrl+z" + +# Key Sequences +var KEYSEQS*: CritBitTree[KeySeq] ## The following key sequences are defined and are used internally by **LineEditor**: +## +## .. code-block:: nim +## KEYSEQS["up"] = @[27, 91, 65] # Windows: @[224, 72] +## KEYSEQS["down"] = @[27, 91, 66] # Windows: @[224, 80] +## KEYSEQS["right"] = @[27, 91, 67] # Windows: @[224, 77] +## KEYSEQS["left"] = @[27, 91, 68] # Windows: @[224, 75] +## KEYSEQS["home"] = @[27, 91, 72] # Windows: @[224, 71] +## KEYSEQS["end"] = @[27, 91, 70] # Windows: @[224, 79] +## KEYSEQS["insert"] = @[27, 91, 50, 126] # Windows: @[224, 82] +## KEYSEQS["delete"] = @[27, 91, 51, 126] # Windows: @[224, 83] + +when defined(windows): + KEYSEQS["up"] = @[224, 72] + KEYSEQS["down"] = @[224, 80] + KEYSEQS["right"] = @[224, 77] + KEYSEQS["left"] = @[224, 75] + KEYSEQS["home"] = @[224, 71] + KEYSEQS["end"] = @[224, 79] + KEYSEQS["insert"] = @[224, 82] + KEYSEQS["delete"] = @[224, 83] +else: + KEYSEQS["up"] = @[27, 91, 65] + KEYSEQS["down"] = @[27, 91, 66] + KEYSEQS["right"] = @[27, 91, 67] + KEYSEQS["left"] = @[27, 91, 68] + KEYSEQS["home"] = @[27, 91, 72] + KEYSEQS["end"] = @[27, 91, 70] + KEYSEQS["insert"] = @[27, 91, 50, 126] + KEYSEQS["delete"] = @[27, 91, 51, 126] + +# Key Mappings +var KEYMAP*: CritBitTree[KeyCallBack] ## The following key mappings are configured by default: +## +## * backspace: **deletePrevious** +## * delete: **deleteNext** +## * insert: *toggle editor mode* +## * down: **historyNext** +## * up: **historyPrevious** +## * ctrl+n: **historyNext** +## * ctrl+p: **historyPrevious** +## * left: **back** +## * right: **forward** +## * ctrl+b: **back** +## * ctrl+f: **forward** +## * ctrl+c: *quits the program* +## * ctrl+d: *quits the program* +## * ctrl+u: **clearLine** +## * ctrl+a: **goToStart** +## * ctrl+e: **goToEnd** +## * home: **goToStart** +## * end: **goToEnd** + +KEYMAP["backspace"] = proc(ed: var LineEditor) = + ed.deletePrevious() +KEYMAP["delete"] = proc(ed: var LineEditor) = + ed.deleteNext() +KEYMAP["insert"] = proc(ed: var LineEditor) = + if ed.mode == mdInsert: + ed.mode = mdReplace + else: + ed.mode = mdInsert +KEYMAP["down"] = proc(ed: var LineEditor) = + ed.historyNext() +KEYMAP["up"] = proc(ed: var LineEditor) = + ed.historyPrevious() +KEYMAP["ctrl+n"] = proc(ed: var LineEditor) = + ed.historyNext() +KEYMAP["ctrl+p"] = proc(ed: var LineEditor) = + ed.historyPrevious() +KEYMAP["left"] = proc(ed: var LineEditor) = + ed.back() +KEYMAP["right"] = proc(ed: var LineEditor) = + ed.forward() +KEYMAP["ctrl+b"] = proc(ed: var LineEditor) = + ed.back() +KEYMAP["ctrl+f"] = proc(ed: var LineEditor) = + ed.forward() +KEYMAP["ctrl+c"] = proc(ed: var LineEditor) = + quit(0) +KEYMAP["ctrl+d"] = proc(ed: var LineEditor) = + quit(0) +KEYMAP["ctrl+u"] = proc(ed: var LineEditor) = + ed.clearLine() +KEYMAP["ctrl+a"] = proc(ed: var LineEditor) = + ed.goToStart() +KEYMAP["ctrl+e"] = proc(ed: var LineEditor) = + ed.goToEnd() +KEYMAP["home"] = proc(ed: var LineEditor) = + ed.goToStart() +KEYMAP["end"] = proc(ed: var LineEditor) = + ed.goToEnd() + +proc readLine*(ed: var LineEditor, prompt="", hidechars = false): string = + ## High-level proc to be used instead of **stdin.readLine** to read a line from standard input using the specified **LineEditor** object. + ## + ## Note that: + ## * **prompt** is a string (that *cannot* contain escape codes, so it cannot be colored) that will be prepended at the start of the line and + ## not included in the contents of the line itself. + ## * If **hidechars** is set to **true**, asterisks will be printed to stdout instead of the characters entered by the user. + stdout.write(prompt) + stdout.flushFile() + ed.line = Line(text: "", position: 0) + var c = -1 # Used to manage completions + var esc = false + while true: + var c1: int + if c > 0: + c1 = c + c = -1 + else: + c1 = getchr() + if esc: + esc = false + continue + elif c1 in {10, 13}: + stdout.write("\n") + ed.historyAdd() + ed.historyFlush() + return ed.line.text + elif c1 in {8, 127}: + KEYMAP["backspace"](ed) + elif c1 in PRINTABLE: + if hidechars: + putchr('*'.ord.cint) + ed.line.text &= c1.chr + ed.line.position.inc + else: + ed.printChar(c1) + elif c1 == 9: # TAB + c = ed.completeLine() + elif c1 in ESCAPES: + var s = newSeq[Key](0) + s.add(c1) + let c2 = getchr() + s.add(c2) + if s == KEYSEQS["left"]: + KEYMAP["left"](ed) + elif s == KEYSEQS["right"]: + KEYMAP["right"](ed) + elif s == KEYSEQS["up"]: + KEYMAP["up"](ed) + elif s == KEYSEQS["down"]: + KEYMAP["down"](ed) + elif s == KEYSEQS["home"]: + KEYMAP["home"](ed) + elif s == KEYSEQS["end"]: + KEYMAP["end"](ed) + elif s == KEYSEQS["delete"]: + KEYMAP["delete"](ed) + elif s == KEYSEQS["insert"]: + KEYMAP["insert"](ed) + elif c2 == 91: + let c3 = getchr() + s.add(c3) + if s == KEYSEQS["right"]: + KEYMAP["right"](ed) + elif s == KEYSEQS["left"]: + KEYMAP["left"](ed) + elif s == KEYSEQS["up"]: + KEYMAP["up"](ed) + elif s == KEYSEQS["down"]: + KEYMAP["down"](ed) + elif s == KEYSEQS["home"]: + KEYMAP["home"](ed) + elif s == KEYSEQS["end"]: + KEYMAP["end"](ed) + elif c3 in {50, 51}: + let c4 = getchr() + s.add(c4) + if c4 == 126 and c3 == 50: + KEYMAP["insert"](ed) + elif c4 == 126 and c3 == 51: + KEYMAP["delete"](ed) + elif c1 in CTRL and KEYMAP.hasKey(KEYNAMES[c1]): + KEYMAP[KEYNAMES[c1]](ed) + else: + # Assuming unhandled two-values escape sequence; do nothing. + if esc: + esc = false + continue + else: + esc = true + continue + +proc password*(ed: var LineEditor, prompt=""): string = + ## Convenience method to use instead of **readLine** to hide the characters inputed by the user. + return ed.readLine(prompt, true) + +when isMainModule: + #proc testChar() = + # while true: + # let a = getchr() + # echo "\n->", a + # if a == 3: + # quit(0) + # + #testChar() + proc testLineEditor() = + var ed = initEditor(historyFile = "") + while true: + echo "---", ed.readLine("-> "), "---" + + testLineEditor()