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//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2023 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
//
//===----------------------------------------------------------------------===//
#if swift(>=6)
@_spi(RawSyntax) public import SwiftSyntax
#else
@_spi(RawSyntax) import SwiftSyntax
#endif
@_spi(Testing)
public struct TriviaParser {
@_spi(Testing)
public static func parseTrivia(_ source: SyntaxText, position: TriviaPosition) -> [RawTriviaPiece] {
if source.isEmpty { return [] }
var pieces: [RawTriviaPiece] = []
var cursor = Lexer.Cursor(
input: UnsafeBufferPointer(start: source.baseAddress, count: source.count),
previous: 0
)
while true {
let start = cursor
switch cursor.advance() {
case nil:
// Finished.
precondition(cursor.isAtEndOfFile)
return pieces
case UInt8(ascii: "\n"):
// "\n"/0A/LF: .newlines.
cursor.advance(while: { $0 == "\n" })
pieces.append(.newlines(start.distance(to: cursor)))
continue
case UInt8(ascii: "\r"):
// "\r\n"/0D0A/CRLF: .carriageReturnLineFeeds.
// "\r"/0D/CR: .carriageReturns.
pieces.append(cursor.lexCarriageReturn(start: start))
continue
case UInt8(ascii: " "):
// " "/20/Space: .spaces.
cursor.advance(while: { $0 == " " })
pieces.append(.spaces(start.distance(to: cursor)))
continue
case UInt8(ascii: "\t"):
// "\t"/09/HT: .tabs.
cursor.advance(while: { $0 == "\t" })
pieces.append(.tabs(start.distance(to: cursor)))
continue
case UInt8(ascii: "\u{000B}"):
// "\v"/0B/VT: .verticalTabs
cursor.advance(while: { $0 == "\u{000B}" })
pieces.append(.verticalTabs(start.distance(to: cursor)))
continue
case UInt8(ascii: "\u{000C}"):
// "\f"/0C/FF: .formfeeds
cursor.advance(while: { $0 == "\u{000C}" })
pieces.append(.formfeeds(start.distance(to: cursor)))
continue
case UInt8(ascii: "/"):
switch cursor.peek() {
case UInt8(ascii: "/"):
pieces.append(cursor.lexLineComment(start: start))
continue
case UInt8(ascii: "*"):
pieces.append(cursor.lexBlockComment(start: start))
continue
default:
break
}
case UInt8(ascii: "#"):
cursor.advance(while: { $0 == "#" })
pieces.append(.pounds(start.distance(to: cursor)))
continue
case UInt8(ascii: "<"), UInt8(ascii: ">"):
// SCM conflict markers.
if cursor.tryLexConflictMarker(start: start) {
pieces.append(.unexpectedText(start.text(upTo: cursor)))
continue
}
case UInt8(ascii: "\\"):
cursor.advance(while: { $0 == "\\" })
pieces.append(.backslashes(start.distance(to: cursor)))
continue
default:
break
}
// Default handling for anything that didn't 'continue' in the above
// switch statement.
// Other characters must be "unexpected text". Advance to next trivia
// piece start.
cursor.advance(while: { char in
switch char {
case " ", "\n", "\r", "\t", "\u{000B}", "\u{000C}", "/", "#", "<", ">":
return false
default:
return true
}
})
// If the last piece was `.unexpectedText` (e.g `/` was in an
// unexpected text trivia piece and were not a comment), merge it to
// the last piece.
if case .unexpectedText(let preUnexpected) = pieces.last {
precondition(start.pointer == preUnexpected.baseAddress! + preUnexpected.count)
let mergedText = SyntaxText(
baseAddress: preUnexpected.baseAddress,
count: preUnexpected.count + start.distance(to: cursor)
)
pieces[pieces.count - 1] = .unexpectedText(mergedText)
} else {
pieces.append(.unexpectedText(start.text(upTo: cursor)))
}
}
return pieces
}
}
extension Lexer.Cursor {
fileprivate mutating func lexCarriageReturn(start: Lexer.Cursor) -> RawTriviaPiece {
precondition(self.previous == UInt8(ascii: "\r"))
if self.advance(if: { $0 == "\n" }) {
var mark = self
while true {
if self.advance(if: { $0 == "\r" }),
self.advance(if: { $0 == "\n" })
{
mark = self
continue
} else {
self = mark
break
}
}
return .carriageReturnLineFeeds(start.distance(to: self) / 2)
} else {
var mark = self
while true {
if self.advance(if: { $0 == "\r" }), !self.advance(if: { $0 == "\n" }) {
mark = self
continue
} else {
self = mark
break
}
}
return .carriageReturns(start.distance(to: self))
}
}
fileprivate mutating func lexLineComment(start: Lexer.Cursor) -> RawTriviaPiece {
// "///...": .docLineComment.
// "//...": .lineComment.
precondition(self.previous == UInt8(ascii: "/") && self.is(at: "/"))
let isDocComment = self.input.count > 1 && self.is(offset: 1, at: "/")
self.advanceToEndOfLine()
let contents = start.text(upTo: self)
return isDocComment ? .docLineComment(contents) : .lineComment(contents)
}
fileprivate mutating func lexBlockComment(start: Lexer.Cursor) -> RawTriviaPiece {
// "/**...*/": .docBlockComment.
// "/*...*/": .blockComment.
// "/**/": .blockComment.
precondition(self.previous == UInt8(ascii: "/") && self.is(at: "*"))
let isDocComment = self.input.count > 2 && self.is(offset: 1, at: "*") && self.is(offset: 2, notAt: "/")
_ = self.advanceToEndOfSlashStarComment(slashPosition: start)
let contents = start.text(upTo: self)
return isDocComment ? .docBlockComment(contents) : .blockComment(contents)
}
}
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