From ba6cd8cf86e630aaf64a519cb0d33449ba95bad7 Mon Sep 17 00:00:00 2001
From: Stephen Celis <stephen@stephencelis.com>
Date: Mon, 11 Apr 2022 14:54:52 -0400
Subject: [PATCH] 185

---
 .../Parsing.playground/Contents.swift         | 152 ++++++++++++++++++
 .../Parsing.playground/contents.xcplayground  |   4 +
 0185-parser-printers-tour-pt1/README.md       |   7 +
 README.md                                     |   1 +
 4 files changed, 164 insertions(+)
 create mode 100644 0185-parser-printers-tour-pt1/Parsing.playground/Contents.swift
 create mode 100644 0185-parser-printers-tour-pt1/Parsing.playground/contents.xcplayground
 create mode 100644 0185-parser-printers-tour-pt1/README.md

diff --git a/0185-parser-printers-tour-pt1/Parsing.playground/Contents.swift b/0185-parser-printers-tour-pt1/Parsing.playground/Contents.swift
new file mode 100644
index 00000000..cae3d320
--- /dev/null
+++ b/0185-parser-printers-tour-pt1/Parsing.playground/Contents.swift
@@ -0,0 +1,152 @@
+import Parsing
+
+let string = String(repeating: "A", count: 10_000)
+let substring = string.dropFirst(10).dropLast(10)
+
+"café"
+"\u{00E9}"
+"e\u{0301}"
+
+"\u{00E9}" == "e\u{0301}"
+
+"\u{00E9}".utf8
+"e\u{0301}".utf8
+Array("\u{00E9}".utf8)
+Array("e\u{0301}".utf8)
+"\u{00E9}".utf8.elementsEqual("e\u{0301}".utf8)
+"\u{00E9}".elementsEqual("e\u{0301}")
+
+struct Dot {
+  let x, y: Int
+}
+enum Direction: String, CaseIterable {
+  case x, y
+}
+struct Fold {
+  let direction: Direction
+  let position: Int
+}
+struct Instructions {
+  let dots: [Dot]
+  let folds: [Fold]
+}
+
+let dotTuple = ParsePrint {
+  Digits()
+  ","
+  Digits()
+}
+try dotTuple.print((3, 1))
+
+let dot = ParsePrint(.memberwise(Dot.init)) {
+  Digits()
+  ","
+  Digits()
+}
+try dot.print(Dot(x: 3, y: 1))
+
+do {
+  try dot.parse("6,10")
+} catch {
+  print(error)
+}
+
+let dots = Many {
+  dot
+} separator: {
+  "\n"
+}
+
+try dots.parse("""
+6,10
+0,14
+9,10
+0,3
+""")
+try dots.print([
+  Dot(x: 3, y: 1),
+  Dot(x: 2, y: 0),
+  Dot(x: 1, y: 4),
+])
+
+// fold ➡️ y=7
+let fold = ParsePrint(.memberwise(Fold.init)) {
+  "fold ➡️ "
+  Direction.parser()
+  "="
+  Digits()
+}
+do {
+  try fold.parse("fold ➡️ y=7")
+} catch {
+  print(error)
+}
+try fold.print(Fold(direction: .x, position: 5))
+
+let folds = Many {
+  fold
+} separator: {
+  "\n"
+}
+
+let instructions = ParsePrint(.memberwise(Instructions.init)) {
+  dots
+  "\n\n"
+  folds
+}
+
+do {
+  let dot = ParsePrint(.memberwise(Dot.init)) {
+    Digits()
+    ",".utf8
+    Digits()
+  }
+  let dots = Many {
+    dot
+  } separator: {
+    "\n".utf8
+  }
+  let fold = ParsePrint(.memberwise(Fold.init)) {
+    "fold ➡️ ".utf8
+    Direction.parser()
+    "=".utf8
+    Digits()
+  }
+  let folds = Many {
+    fold
+  } separator: {
+    "\n".utf8
+  }
+  let instructions = ParsePrint(.memberwise(Instructions.init)) {
+    dots
+    "\n\n".utf8
+    folds
+  }
+}
+
+let input = """
+6,10
+0,14
+9,10
+0,3
+10,4
+4,11
+6,0
+6,12
+4,1
+0,13
+10,12
+3,4
+3,0
+8,4
+1,10
+2,14
+8,10
+9,0
+
+fold ➡️ y=7
+fold ➡️ x=5
+"""
+
+let output = try instructions.parse(input)
+try instructions.print(output) == input
diff --git a/0185-parser-printers-tour-pt1/Parsing.playground/contents.xcplayground b/0185-parser-printers-tour-pt1/Parsing.playground/contents.xcplayground
new file mode 100644
index 00000000..a8211e59
--- /dev/null
+++ b/0185-parser-printers-tour-pt1/Parsing.playground/contents.xcplayground
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<playground version='5.0' target-platform='macos' buildActiveScheme='true'>
+    <timeline fileName='timeline.xctimeline'/>
+</playground>
\ No newline at end of file
diff --git a/0185-parser-printers-tour-pt1/README.md b/0185-parser-printers-tour-pt1/README.md
new file mode 100644
index 00000000..9601e867
--- /dev/null
+++ b/0185-parser-printers-tour-pt1/README.md
@@ -0,0 +1,7 @@
+## [Point-Free](https://www.pointfree.co)
+
+> #### This directory contains code from Point-Free Episode: [Tour of Parser-Printers: Introduction](https://www.pointfree.co/episodes/ep185-tour-of-parser-printers-introduction)
+>
+> Today we celebrate a huge release of swift-parsing, which includes the ability to build invertible parser-printers with ease. We’ll demonstrate by using the library to build three different parser-printers, starting with a fun exercise from Advent of Code.
+
+The following code sample runs with [swift-parsing 0.9.0](https://github.com/pointfreeco/swift-parsing).
diff --git a/README.md b/README.md
index 446f3c91..12c47216 100644
--- a/README.md
+++ b/README.md
@@ -186,3 +186,4 @@ This repository is the home of code written on episodes of [Point-Free](https://
 1. [Parser Printers: Map](0182-parser-printers-pt5)
 1. [Parser Printers: Bizarro Printing](0183-parser-printers-pt6)
 1. [Parser Printers: The Point](0184-parser-printers-pt7)
+1. [Tour of Parser-Printers: Introduction](0185-parser-printers-tour-pt1)