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[Basic] Add a JSON value type.
 - This isn't intended to be a full fledged JSON infrastructure, but we have a need to persist (relatively small) things to disk, and so we need some kind of minimal archiving and encoding infrastructure.
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‎Sources/Basic/JSON.swift

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/*
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This source file is part of the Swift.org open source project
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Copyright 2016 Apple Inc. and the Swift project authors
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Licensed under Apache License v2.0 with Runtime Library Exception
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See http://swift.org/LICENSE.txt for license information
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See http://swift.org/CONTRIBUTORS.txt for Swift project authors
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-------------------------------------------------------------------------
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This file defines JSON support infrastructure. It is not designed to be general
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purpose JSON utilities, but rather just the infrastructure which SwiftPM needs
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to manage serialization of data through JSON.
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*/
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// MARK: JSON Item Definition
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/// A JSON value.
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///
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/// This type uses container wrappers in order to allow for mutable elements.
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public enum JSON {
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/// The null value.
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case null
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/// A boolean value.
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case bool(Bool)
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/// An integer value.
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///
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/// While not strictly present in JSON, we use this as a convenience to
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/// parsing code.
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case int(Int)
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/// A floating-point value.
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case double(Double)
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/// A string.
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case string(String)
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/// An array.
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case array([JSON])
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/// A dictionary.
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case dictionary([String: JSON])
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}
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extension JSON: CustomStringConvertible {
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public var description: Swift.String {
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switch self {
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case .null: return "null"
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case .bool(let value): return value.description
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case .int(let value): return value.description
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case .double(let value): return value.description
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case .string(let value): return value.debugDescription
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case .array(let values): return values.description
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case .dictionary(let values): return values.description
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}
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}
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}
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/// Equatable conformance.
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extension JSON: Equatable { }
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public func ==(lhs: JSON, rhs: JSON) -> Bool {
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switch (lhs, rhs) {
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case (.null, .null): return true
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case (.null, _): return false
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case (.bool(let a), .bool(let b)): return a == b
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case (.bool, _): return false
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case (.int(let a), .int(let b)): return a == b
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case (.int, _): return false
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case (.double(let a), .double(let b)): return a == b
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case (.double, _): return false
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case (.string(let a), .string(let b)): return a == b
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case (.string, _): return false
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case (.array(let a), .array(let b)): return a == b
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case (.array, _): return false
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case (.dictionary(let a), .dictionary(let b)): return a == b
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case (.dictionary, _): return false
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}
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}
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// MARK: JSON Encoding
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extension JSON {
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/// Encode a JSON item into a string of bytes.
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public func toBytes() -> ByteString {
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return (OutputByteStream() <<< self).bytes
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}
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}
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/// Support writing to a byte stream.
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extension JSON: ByteStreamable {
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public func write(to stream: OutputByteStream) {
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switch self {
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case .null:
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stream <<< "null"
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case .bool(let value):
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stream <<< Format.asJSON(value)
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case .int(let value):
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stream <<< Format.asJSON(value)
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case .double(let value):
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// FIXME: What happens for NaN, etc.?
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stream <<< Format.asJSON(value)
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case .string(let value):
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stream <<< Format.asJSON(value)
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case .array(let contents):
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// FIXME: OutputByteStream should just let us do this via conformances.
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stream <<< "["
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for (i, item) in contents.enumerated() {
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if i != 0 { stream <<< ", " }
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stream <<< item
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}
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stream <<< "]"
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case .dictionary(let contents):
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// We always output in a deterministic order.
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//
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// FIXME: OutputByteStream should just let us do this via conformances.
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stream <<< "{"
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for (i, key) in contents.keys.sorted().enumerated() {
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if i != 0 { stream <<< ", " }
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stream <<< Format.asJSON(key) <<< ": " <<< contents[key]!
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}
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stream <<< "}"
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}
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}
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}

‎Tests/Basic/JSONTests.swift

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/*
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This source file is part of the Swift.org open source project
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Copyright 2015 - 2016 Apple Inc. and the Swift project authors
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Licensed under Apache License v2.0 with Runtime Library Exception
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See http://swift.org/LICENSE.txt for license information
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See http://swift.org/CONTRIBUTORS.txt for Swift project authors
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*/
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import XCTest
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@testable import Basic
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class JSONTests: XCTestCase {
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func testEncoding() {
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// Test the basics of encoding each object type.
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func encode(_ item: JSON) -> String {
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return item.toBytes().asString ?? "<unrepresentable>"
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}
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XCTAssertEqual(encode(.bool(false)), "false")
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XCTAssertEqual(encode(.int(1)), "1")
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XCTAssertEqual(encode(.string("hi")), "\"hi\"")
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XCTAssertEqual(encode(.array([.int(1), .string("hi")])), "[1, \"hi\"]")
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XCTAssertEqual(encode(.dictionary(["a": .int(1), "b": .string("hi")])), "{\"a\": 1, \"b\": \"hi\"}")
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}
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}
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extension JSONTests {
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static var allTests: [(String, (JSONTests) -> () throws -> Void)] {
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return [
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("testEncoding", testEncoding),
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]
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}
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}

‎Tests/Basic/XCTestManifests.swift

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public func allTests() -> [XCTestCaseEntry] {
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return [
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testCase(ByteStringTests.allTests),
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testCase(JSONTests.allTests),
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testCase(OptionParserTests.allTests),
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testCase(OutputByteStreamTests.allTests),
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testCase(TOMLTests.allTests),

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