| //===-------------- SyntaxCollection.swift - Syntax Collection ------------===// |
| // |
| // This source file is part of the Swift.org open source project |
| // |
| // Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors |
| // Licensed under Apache License v2.0 with Runtime Library Exception |
| // |
| // See https://swift.org/LICENSE.txt for license information |
| // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors |
| // |
| //===----------------------------------------------------------------------===// |
| |
| import Foundation |
| |
| /// Represents a collection of Syntax nodes of a specific type. SyntaxCollection |
| /// behaves as a regular Swift collection, and has accessors that return new |
| /// versions of the collection with different children. |
| public class SyntaxCollection<SyntaxElement: Syntax>: Syntax { |
| /// Creates a new SyntaxCollection by replacing the underlying layout with |
| /// a different set of raw syntax nodes. |
| /// |
| /// - Parameter layout: The new list of raw syntax nodes underlying this |
| /// collection. |
| /// - Returns: A new SyntaxCollection with the new layout underlying it. |
| internal func replacingLayout( |
| _ layout: [RawSyntax]) -> SyntaxCollection<SyntaxElement> { |
| let newRaw = data.raw.replacingLayout(layout) |
| let (newRoot, newData) = data.replacingSelf(newRaw) |
| return SyntaxCollection<SyntaxElement>(root: newRoot, data: newData) |
| } |
| |
| /// Creates a new SyntaxCollection by appending the provided syntax element |
| /// to the children. |
| /// |
| /// - Parameter syntax: The element to append. |
| /// - Returns: A new SyntaxCollection with that element appended to the end. |
| public func appending( |
| _ syntax: SyntaxElement) -> SyntaxCollection<SyntaxElement> { |
| var newLayout = data.raw.layout |
| newLayout.append(syntax.raw) |
| return replacingLayout(newLayout) |
| } |
| |
| /// Creates a new SyntaxCollection by prepending the provided syntax element |
| /// to the children. |
| /// |
| /// - Parameter syntax: The element to prepend. |
| /// - Returns: A new SyntaxCollection with that element prepended to the |
| /// beginning. |
| public func prepending( |
| _ syntax: SyntaxElement) -> SyntaxCollection<SyntaxElement> { |
| return inserting(syntax, at: 0) |
| } |
| |
| /// Creates a new SyntaxCollection by inserting the provided syntax element |
| /// at the provided index in the children. |
| /// |
| /// - Parameters: |
| /// - syntax: The element to insert. |
| /// - index: The index at which to insert the element in the collection. |
| /// |
| /// - Returns: A new SyntaxCollection with that element appended to the end. |
| public func inserting(_ syntax: SyntaxElement, |
| at index: Int) -> SyntaxCollection<SyntaxElement> { |
| var newLayout = data.raw.layout |
| /// Make sure the index is a valid insertion index (0 to 1 past the end) |
| precondition((newLayout.startIndex...newLayout.endIndex).contains(index), |
| "inserting node at invalid index \(index)") |
| newLayout.insert(syntax.raw, at: index) |
| return replacingLayout(newLayout) |
| } |
| |
| /// Creates a new SyntaxCollection by removing the syntax element at the |
| /// provided index. |
| /// |
| /// - Parameter index: The index of the element to remove from the collection. |
| /// - Returns: A new SyntaxCollection with the element at the provided index |
| /// removed. |
| public func removing(childAt index: Int) -> SyntaxCollection<SyntaxElement> { |
| var newLayout = data.raw.layout |
| newLayout.remove(at: index) |
| return replacingLayout(newLayout) |
| } |
| |
| /// Creates a new SyntaxCollection by removing the first element. |
| /// |
| /// - Returns: A new SyntaxCollection with the first element removed. |
| public func removingFirst() -> SyntaxCollection<SyntaxElement> { |
| var newLayout = data.raw.layout |
| newLayout.removeFirst() |
| return replacingLayout(newLayout) |
| } |
| |
| /// Creates a new SyntaxCollection by removing the last element. |
| /// |
| /// - Returns: A new SyntaxCollection with the last element removed. |
| public func removingLast() -> SyntaxCollection<SyntaxElement> { |
| var newLayout = data.raw.layout |
| newLayout.removeLast() |
| return replacingLayout(newLayout) |
| } |
| } |
| |
| /// Conformance for SyntaxCollection to the Collection protocol. |
| extension SyntaxCollection: Collection { |
| public var startIndex: Int { |
| return data.childCaches.startIndex |
| } |
| |
| public var endIndex: Int { |
| return data.childCaches.endIndex |
| } |
| |
| public func index(after i: Int) -> Int { |
| return data.childCaches.index(after: i) |
| } |
| |
| public subscript(_ index: Int) -> SyntaxElement { |
| return child(at: index)! as! SyntaxElement |
| } |
| } |