function run()

in conductor.js [353:387]

• 29 lines of code
• 11 McCabe index (conditional complexity)

  function run (f, p) {
    // handle let/mask pairs
    const view = []
    let n = 0
    for (let frame of p.s.stack) {
      if (frame.let === null) {
        n++
      } else if (frame.let !== undefined) {
        if (n === 0) {
          view.push(frame)
        } else {
          n--
        }
      }
    }

    // update value of topmost matching symbol on stack if any
    function set (symbol, value) {
      const element = view.find(element => element.let !== undefined && element.let[symbol] !== undefined)
      if (element !== undefined) element.let[symbol] = JSON.parse(JSON.stringify(value))
    }

    // collapse stack for invocation
    const env = view.reduceRight((acc, cur) => cur.let ? Object.assign(acc, cur.let) : acc, {})
    let main = '(function(){try{const require=arguments[2];'
    for (const name in env) main += `var ${name}=arguments[1]['${name}'];`
    main += `return eval((function(){return(${f})})())(arguments[0])}finally{`
    for (const name in env) main += `arguments[1]['${name}']=${name};`
    main += '}})'
    try {
      return (1, eval)(main)(p.params, env, require)
    } finally {
      for (const name in env) set(name, env[name])
    }
  }