56

0056-what-is-a-parser-pt1/Parsers.playground/Contents.swift

@@ -0,0 +1,65 @@
+
+Int("42")
+Int("42-")
+Double("42")
+Double("42.32435")
+Bool("true")
+Bool("false")
+Bool("f")
+
+import Foundation
+
+UUID.init(uuidString: "DEADBEEF-DEAD-BEEF-DEAD-BEEFDEADBEEF")
+UUID.init(uuidString: "DEADBEEF-DEAD-BEEF-DEAD-BEEFDEADBEE")
+UUID.init(uuidString: "DEADBEEF-DEAD-BEEF-DEAD-BEEFDEADBEEZ")
+
+URL.init(string: "https://www.pointfree.co")
+URL.init(string: "^https://www.pointfree.co")
+
+let components = URLComponents.init(string: "https://www.pointfree.co?ref=twitter")
+components?.queryItems
+
+let df = DateFormatter()
+df.timeStyle = .none
+df.dateStyle = .short
+type(of: df.date(from: "1/29/17"))
+df.date(from: "-1/29/17")
+
+
+let emailRegexp = try NSRegularExpression(pattern: #"\S+@\S+"#)
+let emailString = "You're logged in as [email protected]"
+let emailRange = emailString.startIndex..<emailString.endIndex
+let match = emailRegexp.firstMatch(
+  in: emailString,
+  range: NSRange(emailRange, in: emailString)
+  )!
+emailString[Range(match.range(at: 0), in: emailString)!]
+
+//let scanner = Scanner.init(string: "A42 Hello World")
+//var int = 0
+//scanner.scanInt(&int)
+//int
+
+// 40.6782° N, 73.9442° W
+struct Coordinate {
+  let latitude: Double
+  let longitude: Double
+}
+
+func parseLatLong(_ str: String) -> Coordinate? {
+  let parts = str.split(separator: " ")
+  guard parts.count == 4 else { return nil }
+  guard
+    let lat = Double(parts[0].dropLast()),
+    let long = Double(parts[2].dropLast())
+    else { return nil }
+  let latCard = parts[1].dropLast()
+  guard latCard == "N" || latCard == "S" else { return nil }
+  let longCard = parts[3]
+  guard longCard == "E" || longCard == "W" else { return nil }
+  let latSign = latCard == "N" ? 1.0 : -1
+  let longSign = longCard == "E" ? 1.0 : -1
+  return Coordinate(latitude: lat * latSign, longitude: long * longSign)
+}
+
+print(parseLatLong("40.6782% N- 73.9442% W"))

0056-what-is-a-parser-pt1/Parsers.playground/contents.xcplayground

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<playground version='5.0' target-platform='macos'>
+    <timeline fileName='timeline.xctimeline'/>
+</playground>

0056-what-is-a-parser-pt1/README.md

@@ -0,0 +1,5 @@
+## [Point-Free](https://www.pointfree.co)
+
+> #### This directory contains code from Point-Free Episode: [What Is a Parser?: Part 1](https://www.pointfree.co/episodes/ep56-what-is-a-parser-part-1)
+>
+> Parsing is a difficult, but surprisingly ubiquitous programming problem, and functional programming has a lot to say about it. Let’s take a moment to understand the problem space of parsing, and see what tools Swift and Apple gives us to parse complex text formats.

README.md

@@ -58,3 +58,4 @@ This repository is the home of code written on episodes of
 1. [Swift Syntax Enum Properties](0053-swift-syntax-enum-properties)
 1. [Advanced Swift Syntax Enum Properties](0054-advanced-swift-syntax-enum-properties)
 1. [Swift Syntax Command Line Tool](0055-swift-syntax-command-line-tool)
+1. [What Is a Parser?: Part 1](0056-what-is-a-parser-pt1)