6. Keep results together

Keep Counting.kalm from the previous lesson. Add a result record in src/main/kalm/stats/Statistics.kalm:

Statistics.kalm kalm

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pub data Statistics(lines: Int, words: Int)

Add src/main/kalm/stats/Summary.kalm:

Summary.kalm kalm

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pub fun summarize(lines: List<Text>) -> Statistics:
    var words = 0
    for line in lines:
        words += countWords(line)
    return Statistics(len(lines), words)

Replace App.kalm:

App.kalm kalm

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pub fun main() -> Unit:
    fix lines: List<Text> = ["a quiet", "morning"]
    fix result = summarize(lines)
    sayLine(@"${result.lines()} lines / ${result.words()} words")

A data declaration becomes an immutable Java record. Components are available through accessor methods. An empty list yields zero lines and zero words.

Terminal

kalm run

Text

2 lines / 3 words

Read types and contracts for other ways to model data.