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ahoppenahoppen
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Adjust PR to address comments I raised in PR feedback and address other comments found while addressing those
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-482
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4 files changed

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‎Sources/SwiftSyntax/Trivia+commentValue.swift

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//===----------------------------------------------------------------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2025 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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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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extension Trivia {
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/// The contents of all the comment pieces with any comments markers removed and indentation whitespace stripped.
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public var commentValue: String? {
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var comments: [Substring] = []
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/// Keep track of whether we have seen a line or block comment trivia piece. If this `Trivia` contains both a block
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/// and a line comment, we don't know how to concatenate them to form the comment value and thus default to
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/// returning `nil`.
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var hasBlockComment = false
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var hasLineComment = false
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// Determine if all line comments have a space separating the `//` or `///` comment marker and the actual comment.
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lazy var allLineCommentsHaveSpace: Bool = pieces.allSatisfy { piece in
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switch piece {
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case .lineComment(let text): return text.hasPrefix("// ")
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case .docLineComment(let text): return text.hasPrefix("/// ")
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default: return true
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}
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}
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// Strips /* */ markers and remove any common indentation between the lines in the block comment.
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func processBlockComment(_ text: String, isDocComment: Bool) -> String? {
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var lines = text.dropPrefix(isDocComment ? "/**" : "/*").dropSuffix("*/")
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.split(omittingEmptySubsequences: false, whereSeparator: \.isNewline)
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// If the comment content starts on the same line as the `/*` marker or ends on the same line as the `*/` marker,
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// it is common to separate the marker and the actual comment using spaces. Strip those spaces if they exists.
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// If there are non no-space characters on the first / last line, then the comment doesn't start / end on the line
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// with the marker, so don't do the stripping.
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if let firstLine = lines.first, firstLine.contains(where: { $0 != " " }) {
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lines[0] = firstLine.drop { $0 == " " }
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}
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if let lastLine = lines.last, lastLine.contains(where: { $0 != " " }) {
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lines[lines.count - 1] = lastLine.dropLast { $0 == " " }
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}
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var indentation: Substring? = nil
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// Find the lowest indentation that is common among all lines in the block comment. Do not consider the first line
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// because it won't have any indentation since it starts with /*
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for line in lines.dropFirst() {
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let lineIndentation = line.prefix(while: { $0 == " " || $0 == "\t" })
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guard let previousIndentation = indentation else {
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indentation = lineIndentation
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continue
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}
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indentation = commonPrefix(previousIndentation, lineIndentation)
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}
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guard let firstLine = lines.first else {
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// We did not have any lines. This should never happen in practice because `split` never returns an empty array
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// but be safe and return `nil` here anyway.
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return nil
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}
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var unindentedLines = [firstLine] + lines.dropFirst().map { $0.dropPrefix(indentation ?? "") }
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// If the first line only contained the comment marker, don't include it. We don't want to start the comment value
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// with a newline if `/*` is on its own line. Same for the end marker.
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if unindentedLines.first?.allSatisfy({ $0 == " " }) ?? false {
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unindentedLines.removeFirst()
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}
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if unindentedLines.last?.allSatisfy({ $0 == " " }) ?? false {
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unindentedLines.removeLast()
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}
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// We canonicalize the line endings to `\n` here. This matches how we concatenate the different line comment
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// pieces using \n as well.
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return unindentedLines.joined(separator: "\n")
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}
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for piece in pieces {
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switch piece {
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case .blockComment(let text), .docBlockComment(let text):
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if hasBlockComment || hasLineComment {
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return nil
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}
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hasBlockComment = true
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guard let processedText = processBlockComment(text, isDocComment: piece.isDocComment) else {
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return nil
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}
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comments.append(processedText[...])
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case .lineComment(let text), .docLineComment(let text):
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if hasBlockComment {
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return nil
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}
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hasLineComment = true
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let prefixToDrop = (piece.isDocComment ? "///" : "//") + (allLineCommentsHaveSpace ? " " : "")
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comments.append(text.dropPrefix(prefixToDrop))
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default:
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break
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}
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}
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if comments.isEmpty { return nil }
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return comments.joined(separator: "\n")
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}
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}
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fileprivate extension StringProtocol where SubSequence == Substring {
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func dropPrefix(_ prefix: some StringProtocol) -> Substring {
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if self.hasPrefix(prefix) {
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return self.dropFirst(prefix.count)
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}
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return self[...]
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}
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func dropSuffix(_ suffix: some StringProtocol) -> Substring {
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if self.hasSuffix(suffix) {
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return self.dropLast(suffix.count)
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}
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return self[...]
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}
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func dropLast(while predicate: (Self.Element) -> Bool) -> Self.SubSequence {
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let dropLength = self.reversed().prefix(while: predicate)
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return self.dropLast(dropLength.count)
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}
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}
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fileprivate func commonPrefix(_ lhs: Substring, _ rhs: Substring) -> Substring {
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return lhs[..<lhs.index(lhs.startIndex, offsetBy: zip(lhs, rhs).prefix { $0 == $1 }.count)]
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}
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fileprivate extension TriviaPiece {
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var isDocComment: Bool {
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switch self {
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case .docBlockComment, .docLineComment: return true
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default: return false
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}
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}
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}

‎Sources/SwiftSyntax/Trivia.swift

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@@ -42,137 +42,6 @@ public struct Trivia: Sendable {
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pieces.isEmpty
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}
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/// The string contents of all the comment pieces with any comments tokens trimmed.
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public var commentValue: String? {
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var comments = [Substring]()
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var hasBlockComment = false
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var hasLineComment = false
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// Determine if all line comments have a single space
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lazy var allLineCommentsHaveSpace: Bool = {
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return pieces.allSatisfy { piece in
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switch piece {
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case .lineComment(let text):
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return text.hasPrefix("// ")
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case .docLineComment(let text):
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return text.hasPrefix("/// ")
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default:
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return true
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}
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}
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}()
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// Returns a substring with leading and trailing spaces removed.
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func trimWhitespace(_ text: Substring) -> Substring {
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let trimmed = text.drop(while: { $0 == " " })
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let reversed = trimmed.reversed()
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let trimmedEnd = reversed.drop(while: { $0 == " " })
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let final = trimmedEnd.reversed()
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return Substring(final)
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}
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// Strips /* */ markers and aligns content by removing common indentation.
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func processBlockComment(_ text: Substring) -> String {
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var lines = text.split(separator: "\n", omittingEmptySubsequences: false)
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let (minSpaceIndentation, minTabIndentation) =
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lines
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.dropFirst()
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.filter { !$0.isEmpty }
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.reduce((Int.max, Int.max)) { (currentMin, line) in
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var spaceCount = 0, tabCount = 0
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var inLeadingWhitespace = true
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for char in line {
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guard inLeadingWhitespace else { break }
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switch char {
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case " ":
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spaceCount += 1
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case "\t":
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tabCount += 1
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default:
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inLeadingWhitespace = false
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}
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}
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return (Swift.min(currentMin.0, spaceCount), Swift.min(currentMin.1, tabCount))
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}
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var minIndentation = minSpaceIndentation == Int.max ? 0 : minSpaceIndentation
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minIndentation += minTabIndentation == Int.max ? 0 : minTabIndentation
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if let first = lines.first {
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let prefixToDrop = first.hasPrefix("/**") ? 3 : 2
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lines[0] = first.dropFirst(prefixToDrop)
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}
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var firstLineRemoved = false
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if trimWhitespace(lines[0]).isEmpty {
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lines.removeFirst()
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firstLineRemoved = true
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}
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var unindentedLines = lines.enumerated().map { index, line -> Substring in
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if index == 0 && firstLineRemoved == false {
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return line
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}
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return line.count >= minIndentation ? line.dropFirst(minIndentation) : line
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}
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if let last = unindentedLines.last, last.hasSuffix("*/") {
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unindentedLines[unindentedLines.count - 1] = last.dropLast(2)
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}
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if trimWhitespace(unindentedLines[unindentedLines.count - 1]).isEmpty {
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unindentedLines.removeLast()
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}
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return unindentedLines.joined(separator: "\n")
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}
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for piece in pieces {
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switch piece {
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case .blockComment(let text), .docBlockComment(let text):
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if hasBlockComment || hasLineComment {
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return nil
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}
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hasBlockComment = true
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let processedText = processBlockComment(text[...])
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comments.append(processedText[...])
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case .lineComment(let text):
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if hasBlockComment {
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return nil
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}
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hasLineComment = true
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let prefix = allLineCommentsHaveSpace ? "// " : "//"
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comments.append(text.dropFirst(prefix.count))
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case .docLineComment(let text):
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if hasBlockComment {
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return nil
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}
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hasLineComment = true
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let prefix = allLineCommentsHaveSpace ? "/// " : "///"
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comments.append(text.dropFirst(prefix.count))
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default:
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break
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}
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}
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guard !comments.isEmpty else { return nil }
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// If we have multiple line comments, they can be joined with newlines
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if hasLineComment {
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return comments.joined(separator: "\n")
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}
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// In case of block comments, we should only have one
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return comments.first.map(String.init)
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}
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/// The length of all the pieces in this ``Trivia``.
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public var sourceLength: SourceLength {
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return pieces.map({ $0.sourceLength }).reduce(.zero, +)

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