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luhn-generator

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A generator of numbers that passes the validation of Luhn algorithm or Luhn formula, also known as the 'modulus 10' or 'mod 10' algorithm

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"use strict"; const h = require("./helpers"); const PatternMatch = require("./pattern-match"); module.exports = t => { // small abstractions const not = node => t.unaryExpression("!", node); const notnot = node => not(not(node)); const or = (a, b) => t.logicalExpression("||", a, b); const and = (a, b) => t.logicalExpression("&&", a, b); function simplifyPatterns(path) { const test = path.get("test"); const consequent = path.get("consequent"); const alternate = path.get("alternate"); const _h$typeSymbols = h.typeSymbols(t), EX = _h$typeSymbols.Expression; // Convention: // =============== // for each pattern [test, consequent, alternate, handler(expr, cons, alt)] const matcher = new PatternMatch([[EX, true, false, e => notnot(e)], [EX, false, true, e => not(e)], [EX, true, EX, (e, c, a) => or(notnot(e), a)], [EX, false, EX, (e, c, a) => and(not(e), a)], [EX, EX, true, (e, c) => or(not(e), c)], [EX, EX, false, (e, c) => and(notnot(e), c)]]); const result = matcher.match([test, consequent, alternate], h.isPatternMatchesPath(t)); if (result.match) { path.replaceWith(result.value(test.node, consequent.node, alternate.node)); } } return { simplifyPatterns }; };