Text Pipeline - Swift Programming

A text pipeline keeps lines with a chosen prefix and joins the result.

Filter lines by prefix

text_pipeline.swift

let prefix = 
let lines = [
    "TODO write outline",
    "DONE review draft",
    "TODO publish page"
]
var matches: [String] = []

for line in lines {
    if line.hasPrefix(prefix) {
        matches.append(line)
    }
}

let output = matches.joined(separator: " | ")

print(output)

let prefix = 
let lines = [
    "TODO write outline",
    "DONE review draft",
    "TODO publish page"
]
var matches: [String] = []

for line in lines {
    if line.hasPrefix(prefix) {
        matches.append(line)
    }
}

let output = matches.joined(separator: " | ")

print(output)

let prefix = 
let lines = [
    "TODO write outline",
    "DONE review draft",
    "TODO publish page"
]
var matches: [String] = []

for line in lines {
    if line.hasPrefix(prefix) {
        matches.append(line)
    }
}

let output = matches.joined(separator: " | ")

print(output)

text pipeline Small text tools often run a sequence of steps: read lines, filter them, then format the result.