feat: Initial commit

Sources/main.swift

@@ -0,0 +1,190 @@
+import Foundation
+@preconcurrency import Parsing
+
+let yamlString = """
+---
+author: Michael Housh
+categories:
+  - HVAC
+  - General
+  - Programming
+copy: true
+draft: false
+date: 2023-10-21
+lastmod: 2023-10-21
+image: banner.png
+featuredImage: banner.png
+series:
+  - General
+tags:
+  - HVAC
+  - General
+  - Programming
+
+---
+"""
+
+_ = """
+title: "You Should Learn Markdown"
+slug: "you-should-learn-markdown"
+"""
+
+enum YamlItem {
+  case boolean(Bool)
+  case date(year: Int, month: Int, day: Int)
+  case string(String)
+
+  private static let dateParser = Parse(input: Substring.self) {
+    Digits(4)
+    "-"
+    Digits(2)
+    "-"
+    Digits(2)
+  }.map { Self.date(year: $0.0, month: $0.1, day: $0.2) }
+
+  private static let booleanParser = Parse(input: Substring.self) {
+    Bool.parser()
+  }.map { Self.boolean($0) }
+
+  private static let quotedString = Parse(input: Substring.self) {
+    "\""
+    PrefixUpTo("\"")
+    "\""
+  }
+
+  private static let stringParser = Parse(input: Substring.self) {
+    OneOf {
+      quotedString
+      Rest()
+    }
+  }.map { Self.string(String($0)) }
+
+  static let parser = OneOf {
+    dateParser
+    booleanParser
+    stringParser
+  }
+}
+
+enum YamlLine {
+  case keyValue(String, YamlItem)
+  case list(String, [String])
+
+  static let parser = OneOf {
+    listParser
+    keyValueParser
+  }
+
+  static let keyParser = Parse(input: Substring.self) {
+    PrefixUpTo(":")
+    ":"
+  }.map(String.init)
+
+  static let keyValueParser = Parse(input: Substring.self) {
+    PrefixUpTo(":").map(String.init)
+    ": "
+    YamlItem.parser
+  }.map { YamlLine.keyValue($0.0, $0.1) }
+
+  static let listLineParser = Parse(input: Substring.self) {
+    Skip { PrefixThrough("- ") }
+    PrefixUpTo("\n").map(String.init)
+    "\n"
+  }
+
+  static let listParser = Parse(input: Substring.self) {
+    PrefixUpTo(":\n").map(String.init)
+    ":\n"
+    Many {
+      Skip { PrefixThrough("- ") }
+      PrefixUpTo("\n").map(String.init)
+      "\n"
+    }
+  }
+  .map { YamlLine.list($0.0, $0.1) }
+}
+
+let yamlBlockParser = Parse(input: Substring.UTF8View.self) {
+  "---\n".utf8
+  Many {
+    PrefixUpTo("\n".utf8)
+    // From(.substring) { YamlLine.parser }
+  } separator: {
+    "\n".utf8
+  }
+  "\n".utf8
+  "---".utf8
+}
+
+// let yamlLineParser = Parse(input: Substring.UTF8View.self) {
+//   PrefixUpTo(":".utf8).map(String.init)
+//   ":".utf8
+//   OneOf {
+//     PrefixUpTo("\n".utf8)
+//     Rest()
+//   }.map(String.init)
+// }
+
+let stringLine = #"author: "Michael Housh""#
+// let parsedLine = try yamlLineParser.parse(stringLine[...].utf8)
+// print(parsedLine)
+
+let stringItem = "foo"
+let quotedItem = "\"foo\""
+let dateItem = "2025-01-29"
+let boolItem = "true"
+
+try print(YamlItem.parser.parse(stringItem[...]))
+try print(YamlItem.parser.parse(quotedItem[...]))
+try print(YamlItem.parser.parse(dateItem[...]))
+try print(YamlItem.parser.parse(boolItem[...]))
+
+let kvLine = "author: Michael Housh"
+var listLine = """
+test:
+  - HVAC
+  - General
+  - Programming
+
+"""[...]
+
+try print(YamlLine.parser.parse(kvLine[...]))
+try print(YamlLine.parser.parse(&listLine))
+print(listLine)
+
+// try print(YamlItem.parser.parse(listItem[...]))
+
+var yamlLines = """
+author: Michael Housh
+test:
+  - HVAC
+  - General
+  - Programming
+
+"""[...]
+
+let lineParser = Many {
+  YamlLine.parser
+} separator: {
+  "\n"
+}
+
+try print(lineParser.parse(yamlLines))
+
+// let lines = try yamlBlockParser.parse(yamlString[...].utf8)
+//
+// for line in lines {
+//   print("line: \(String(line)!)")
+//   if let parsed = try? YamlLine.keyValueParser.parse(Substring(line)) {
+//     print(parsed)
+//   } else {
+//     if let key = try? YamlLine.keyParser.parse(Substring(line)) {
+//       print("found key: \(String(key))")
+//     } else {
+//       print("not key value.")
+//     }
+//   }
+// }
+
+// print(lines.map(String.init))
+// print(lines)