Asking the IDE

The bar at the top of the window answers questions: /h for a type, a keyword or an error code, /q for a question, /t for a tool. Each answers in a tab of the bottom panel, instantly, and none of them changes your code. Resting the pointer on a name explains it too. To play it in the IDE: Help > Lessons > Getting started…, or ek9 -ide -lesson asking-the-ide.

The EK9 IDE as the lesson opens

Start from

The code the lesson starts from: copy it into a file of your own and follow the steps.

#!ek9
defines module lesson.showcase

  defines constant
    WARM <- 25

  defines class

    Readings
      values as List of Integer: List() of Integer
      peak as Integer: Integer()

      record()
        -> reading as Integer
        values += Integer(reading)
        if not peak? or reading > peak
          peak := Integer(reading)

      summary() as pure
        <- rtn as String?

        if peak > WARM
          rtn: `${length values} readings, peak ${peak} - warm`
        else
          rtn: `${length values} readings, peak ${peak} - mild`

      warmReadings()
        <- rtn as List of Integer: cat values | filter by isWarm | collect as List of Integer

      operator $ as pure
        <- rtn as String: `Readings: ${length values}, peak ${peak}`

      default operator ?

  defines function

    isWarm() as pure
      -> reading as Integer
      <- rtn as Boolean: reading > WARM

  defines program

    ShowReadings()
      stdout <- Stdout()
      station <- Readings()
      station.record(18)
      station.record(27)
      station.record(30)

      stdout.println(station.summary())
      stdout.println(`Warm readings: ${station.warmReadings()}`)

//EOF

Step 1: A type or a keyword: /h

Type /h String in the input bar and press Enter. The Help tab shows what a String offers - its constructors, methods and operators. Try /h record, or /h E05030 for an error.

The EK9 IDE once this is done: Type /h String in the input bar and press Enter

Step 2: A question: /q

Type /q followed by some words - /q read compiler error messages - and press Enter. The Answers tab lists the questions that match, each with a worked example. A question's number, /q 247, opens just that one.

The EK9 IDE once this is done: Type /q followed by some words - /q read compiler error messages - and press Enter

Step 3: A tool: /t

Type /t rename and press Enter. The Tooling tab lists the tools that match - the same ones an AI assistant is given. A tool's name, /t ek9_rename_symbol, shows its arguments.

The EK9 IDE once this is done: Type /t rename and press Enter

Step 4: A name in the editor: Hovers

Rest the pointer on peak, in the editor. The Hovers panel, at the right, explains it. An error rested on is explained there too, in full.

The EK9 IDE once this is done: Rest the pointer on peak, in the editor

The result

/h answers in the Help tab (a type, a keyword or an error code), /q in the Answers tab (a question, by its words or its number) and /t in the Tooling tab (a tool) - the same text as ek9 -h, ek9 -q and ek9 -tool in a terminal. The Hovers panel explains whatever the pointer rests on, and typing show me how in the bar lists the lessons.

Where this lesson comes from

In the EK9 reference: Introduction to EK9