word_freq.swift in Swift

A word-frequency table from split, a defaulted subscript, one sort.

// Count word frequencies in a passage and chart the leaders.

import Foundation

let passage = "the rain in maine falls mainly on the plain and "
    + "the rain stays on the plain"

// Tally every word; default: reads a zero for new keys.
var counts: [String: Int] = [:]
for word in passage.split(separator: " ") {
    counts[String(word), default: 0] += 1
}

// Rank the entries, biggest first, ties broken by the word itself.
let ranked = counts.sorted {
    $0.value != $1.value ? $0.value > $1.value : $0.key < $1.key
}

print("\(ranked.count) distinct words")
print("word    ct bar")
for (word, n) in ranked {
    let padded = word.padding(toLength: 7, withPad: " ", startingAt: 0)
    let count = String(n).count == 1 ? " \(n)" : "\(n)"
    let bar = String(repeating: "#", count: n)
    print("\(padded) \(count) \(bar)")
}

How it works

1. counts[word, default: 0] += 1 tallies without a guard.
2. The sort ranks by count with alphabetical ties in one closure.
3. String(repeating:count:) draws each word's bar.

Keywords and builtins used here

• Foundation
• Int
• String
• count
• default
• for
• import
• in
• let
• print
• sorted
• split
• var

The run, in numbers

Lines

26

Characters to type

804

Tokens

188

Three-star pace

65 tpm

At the three-star pace of 65 tokens a minute, this run takes about 174 seconds.

Type this snippet

Step 1 of 3 in Encore, step 25 of 27 in Language basics.

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