src/nodejs/jsugar

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  • Syntax sugar and convenience functions for JavaScript.

Example:

import src/nodejs/jsugar
from std/jsffi import JsObject
from std/sugar import `=>`

doAssert generate2FAcode() is cint
doAssert not uuid1validate("".cstring)
doAssert not uuid4validate("".cstring)
doAssert not uuid5validate("".cstring)
doAssert uuid1validate("e64cb2a6-3ff6-11eb-b378-0242ac130002".cstring)
doAssert uuid4validate("854fc25b-02f3-45cc-b521-516991b9bb99".cstring)
doAssert nextDays() is seq[JsObject]
doAssert pastDays() is seq[JsObject]

discard sparkline([1.cint, 2, 3, 4, 5], minimum = 0.cint, maximum = 10.cint)

iife:
  # (() => {
  echo "Hello Immediately Invoked Function Expressions"
  # })();

constant ::= "This is a JavaScript 'const'!.".cstring
# const constant = "This is a JavaScript 'const'!.";

proc example(argument0, argument1: int) {.codegenDecl: arrow.} =
  # const example = (argument0, argument1) => {
  echo "JavaScript Arrow Function for Nim functions"
  # }

let example2 = (arg0, arg1: int) {.codegenDecl: arrow.} => echo "JavaScript Arrow Function for Nim Arrow Functions"
# const example2 = (arg0, arg01) => { echo("JavaScript Arrow Function for Nim functions") };

doAssert nth(-9.cint) == "-9th".cstring
doAssert nth(0.cint) == "0th".cstring
doAssert nth(9.cint) == "9th".cstring
doAssert nth(1.cint) == "1st".cstring
doAssert nth(42.cint) == "42nd".cstring
doAssert nth(420.cint) == "420th".cstring
doAssert nth(666.cint) == "666th".cstring

doAssert toRGB("c0ffee".cstring) == [192.cint, 255, 238]
doAssert toHex([192.cint, 255, 238]) == "c0ffee".cstring

doAssert removeAccents("ÇáéíóúýÁÉÍÓÚÝàèìòùÀÈÌÒÙãõñäëïöüÿÄËÏÖÜÃÕÑâêîôûÂÊÎÔ".cstring) == "CaeiouyAEIOUYaeiouAEIOUaonaeiouyAEIOUAONaeiouAEIO".cstring
doAssert removeAccents("È,É,Ê,Ë,Û,Ù,Ï,Î,À,Â,Ô,è,é,ê,ë,û,ù,ï,î,à,â,ô,Ç,ç,Ã,ã,Õ,õ".cstring) == "E,E,E,E,U,U,I,I,A,A,O,e,e,e,e,u,u,i,i,a,a,o,C,c,A,a,O,o".cstring

doAssert editDistanceAscii("Kitten".cstring, "Bitten".cstring) == 1.cint ## Levenshtein distance

when off:
  jsexport constant, example, example2
  # export { constant, example, example2 };

Consts

arrow = "const $2 = ($3) =>"
Arrow Function for Nim functions, use {.codegenDecl: arrow.}. 
maxValidDate = "8640000000000000"
new Date(8640000000000001) "Invalid Date". (Same as Math.pow(10, 8) * 24 * 60 * 60 * 1000) 
minValidDate = "-8640000000000000"
new Date(-8640000000000001) "Invalid Date". (Same as -maxValidDate)

Procs

func anyToCstring(thing: auto): cstring {.
    importjs: "(new TextDecoder(\'utf-8\').decode(#))", ...raises: [], tags: [].}
https://github.com/juancarlospaco/nodejs/issues/1#issuecomment-851956152 
func currentTimestamp(): int {.importjs: """Math.floor(new Date().getTime() / 1000)""",
                               ...raises: [], tags: [].}
func daysBetweenYears(fromYear, toYear: Positive): int {....raises: [], tags: [].}
Get the number of days between fromYear-01-01 and toYear-01-01.

Example:

doAssert daysBetweenYears(1970, 2020) == 18262
doAssert daysBetweenYears(2000, 2020) == 7305
doAssert daysBetweenYears(1970, 1970) == 0
doAssert daysBetweenYears(2020, 2020) == 0
doAssert daysBetweenYears(1999, 2000) == 365
func editDistanceAscii(a, b: cstring): cint {.importjs: """  (() => {
    const s0 = #;
    const s1 = #;
    if (s0 === s1)  return 0;
    if (!s0 || !s1) return Math.max(s0.length, s1.length);

    var prevRow = new Array(s1.length + 1);
    for (var i = 0; i < prevRow.length; ++i) {
      prevRow[i] = i;
    }

    for (i = 0; i < s0.length; ++i) {
      var result = i + 1;
      for (var j = 0; j < s1.length; ++j) {
        var curCol = result;
        result = prevRow[j] + ( (s0.charAt(i) === s1.charAt(j)) ? 0 : 1 );
        var tmp = curCol + 1;
        if (result > tmp) {
          result = tmp;
        }
        tmp = prevRow[j + 1] + 1;
        if (result > tmp) {
          result = tmp;
        }
        prevRow[j] = curCol;
      }
      prevRow[j] = result;
    }
    return result;
  })()""",
    ...raises: [], tags: [].}
https://github.com/hiddentao/fast-levenshtein 
func generate2FAcode(): cint {.importjs: "parseInt(Math.floor(Math.random() * 1000000).toString().padStart(6, \'0\'))",
                               ...raises: [], tags: [].}
Convenience func to generate a valid 2 Factor Authentication code integer. 
func jsexport(symbols: auto) {.importjs: "export { @ }", varargs, ...raises: [],
                               tags: [].}
Convenience alias for export { symbol0, symbol1, symbol2 }; 
func nextDays(days = 7.cint): seq[JsObject] {.importjs: "[...Array(#).keys()].map(days => new Date(Date.now() + 86400000 * days))",
    ...raises: [], tags: [].}
Convenience func to create an seq of the next days, inclusive. 
func nth(someOrdinalInteger: cint): cstring {.importjs: """  (() => {
    const n = #;
    if (/^(string|number)$$/.test(typeof n) === false) { return n; }
    let suffixes = ['th', 'st', 'nd', 'rd', 'th', 'th', 'th', 'th', 'th', 'th'], match = n.toString().match(/\d$$/), suffix;
    if (!match) { return n; }
    suffix = suffixes[match[0]];
    if (/1[123]$$/.test(n)) { suffix = 'th'; }
    return n + suffix;
  })()""",
    ...raises: [], tags: [].}
Convenience func to get string ordinal suffixes from integers ("1st", "2nd", "3rd", etc). 
func pastDays(days = 7.cint): seq[JsObject] {.importjs: "[...Array(#).keys()].map(days => new Date(Date.now() - 86400000 * days))",
    ...raises: [], tags: [].}
Convenience func to create an seq of the past days, inclusive. 
func removeAccents(s: cstring): cstring {.importjs: """(#
  .replace(/[\xC0-\xC5]/g, "A").replace(/[\xC6]/g, "AE").replace(/[\xC7]/g, "C")
  .replace(/[\xC8-\xCB]/g, "E").replace(/[\xCC-\xCF]/g, "I").replace(/[\xD0]/g, "D")
  .replace(/[\xD1]/g, "N").replace(/[\xD2-\xD6\xD8]/g, "O").replace(/[\xD9-\xDC]/g, "U")
  .replace(/[\xDD]/g, "Y").replace(/[\xDE]/g, "P").replace(/[\xE0-\xE5]/g, "a")
  .replace(/[\xE6]/g, "ae").replace(/[\xE7]/g, "c").replace(/[\xE8-\xEB]/g, "e")
  .replace(/[\xEC-\xEF]/g, "i").replace(/[\xF1]/g, "n").replace(/[\xF2-\xF6\xF8]/g, "o")
  .replace(/[\xF9-\xFC]/g, "u").replace(/[\xFE]/g, "p").replace(/[\xFD\xFF]/g, "y"))""",
    ...raises: [], tags: [].}
Convenience func to replace accented chars (Diacritics) with normal chars (ASCII). 
func shuffle(arrai: openArray[auto]) {.importjs: """#.sort(() => .5 - Math.random())""",
                                       ...raises: [], tags: [].}

Example:

var x = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
shuffle(x)
doAssert x != [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
func sparkline(numbers: openArray[cint]; minimum: cint; maximum: cint): cstring {.
    asmNoStackFrame, ...raises: [], tags: [].}
Convenience func to generate "Sparklines" loading spinners from numbers. 
func suffixAmPm(s: SomeInteger): cstring {.importjs: """  ((h = Math.abs(#)) => `$${h % 12 === 0 ? 12 : h % 12}$${h < 12 ? 'am' : 'pm'}`)()""",
    ...raises: [], tags: [].}

Example:

doAssert suffixAmPm(0) == "12am".cstring
doAssert suffixAmPm(5) == "5am".cstring
doAssert suffixAmPm(12) == "12pm".cstring
doAssert suffixAmPm(15) == "3pm".cstring
doAssert suffixAmPm(23) == "11pm".cstring
doAssert suffixAmPm(-23) == "11pm".cstring
func toHex(color: array[3, cint]): cstring {.importjs: """  (() => { const n = #; return ((n[2] | n[1] << 8 | n[0] << 16) | 1 << 24).toString(16).slice(1); })()""",
    ...raises: [], tags: [].}
Convenience func to convert a RGB integer array to 6 digit Hexadecimal string. 
func toRGB(color: cstring): array[3, cint] {.importjs: """  (() => { const n = parseInt(#, 16); return [n >> 16, n >> 8 & 255, n & 255] })()""",
    ...raises: [], tags: [].}
Convenience func to convert a 6 digit Hexadecimal string value to an RGB integer array. 
func uuid1validate(uuidv1: cstring): bool {.importjs: """  (() => {
    const UUID_RE1 = new RegExp("^[0-9a-f]{8}-[0-9a-f]{4}-1[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$$", "i");
    return UUID_RE1.test(#);
  })()""",
    ...raises: [], tags: [].}
Convenience func to validate 1 UUID v1 string. 
func uuid4validate(uuidv4: cstring): bool {.importjs: """  (() => {
    const UUID_RE4 = new RegExp("^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$$", "i");
    return UUID_RE4.test(#);
  })()""",
    ...raises: [], tags: [].}
Convenience func to validate 1 UUID v4 string. 
func uuid5validate(uuidv5: cstring): bool {.importjs: """  (() => {
    const UUID_RE5 = /^[0-9a-f]{8}-[0-9a-f]{4}-[5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$$/i;
    return UUID_RE5.test(#);
  })()""",
    ...raises: [], tags: [].}
Convenience func to validate 1 UUID v5 string.

Iterators

iterator backoff[T: SomeNumber](a, b: T; factor: T = 2): T
Exponential backoff

Example:

block:
  var example: seq[int]
  for i in backoff(1, 9): example.add i
  doAssert example == @[1, 2, 4, 8]
block:
  var example: seq[float]
  for i in backoff(1.0, 9.9): example.add i
  doAssert example == @[1.0, 2.0, 4.0, 8.0]

Templates

template `::=`(name: untyped; value: auto): untyped
Convenience template for a JavaScript const (Nim var). Other libs already use := then we use ::=, because :== looks like a comparison. 
template iife(code: untyped): untyped
Convenience template for Anonymous Immediately Invoked Function Expressions.

Made with Nim. Generated: 2022-02-14 22:50:49 UTC