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Formatter.swift
636 lines (572 loc) · 24.8 KB
/
Formatter.swift
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//
// Formatter.swift
// SwiftFormat
//
// Version 0.44.8
//
// Created by Nick Lockwood on 12/08/2016.
// Copyright 2016 Nick Lockwood
//
// Distributed under the permissive MIT license
// Get the latest version from here:
//
// https://github.com/nicklockwood/SwiftFormat
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//
import Foundation
/// This is a utility class used for manipulating a tokenized source file.
/// It doesn't actually contain any logic for formatting, but provides
/// utility methods for enumerating and adding/removing/replacing tokens.
/// The primary advantage it provides over operating on the token array
/// directly is that it allows mutation during enumeration, and
/// transparently handles changes that affect the current token index.
public class Formatter: NSObject {
private var enumerationIndex = -1
private var disabledCount = 0
private var disabledNext = 0
private var wasNextDirective = false
// Formatting range
public var range: Range<Int>?
// Current rule, used for handling comment directives
var currentRule: FormatRule? {
didSet {
disabledCount = 0
disabledNext = 0
}
}
// Is current rule enabled
var isEnabled: Bool {
guard range?.contains(enumerationIndex) != false else {
return false
}
return disabledCount + disabledNext <= 0
}
// Process a comment token (which may contain directives)
func processCommentBody(_ comment: String) {
let prefix = "swiftformat:"
guard let rule = currentRule, comment.hasPrefix(prefix),
let directive = ["disable", "enable"].first(where: { comment.hasPrefix("\(prefix)\($0)") }),
comment.range(of: "\\b(\(rule.name)|all)\\b", options: .regularExpression) != nil else {
return
}
wasNextDirective = comment.hasPrefix("\(prefix)\(directive):next")
switch directive {
case "disable":
if wasNextDirective {
disabledNext = 1
} else {
disabledCount += 1
}
case "enable":
if wasNextDirective {
disabledNext = -1
} else {
disabledCount -= 1
}
default:
preconditionFailure()
}
}
/// Process a linebreak (used to cancel disable/enable:next directive)
func processLinebreak() {
if wasNextDirective {
wasNextDirective = false
} else if disabledNext != 0 {
disabledNext = 0
}
}
/// The options that the formatter was initialized with
public let options: FormatOptions
/// The token array managed by the formatter (read-only)
public private(set) var tokens: [Token]
/// Create a new formatter instance from a token array
public init(_ tokens: [Token], options: FormatOptions = FormatOptions(),
trackChanges: Bool = false, range: Range<Int>? = nil) {
self.tokens = tokens
self.options = options
self.trackChanges = trackChanges
self.range = range
}
// MARK: changes made
/// Change record
public struct Change: Equatable, CustomStringConvertible {
public let line: Int
public let rule: FormatRule
public let filePath: String?
public var description: String {
let help = stripMarkdown(rule.help).replacingOccurrences(of: "\n", with: " ")
return "\(filePath ?? ""):\(line):1: warning: (\(rule.name)) \(help)"
}
}
/// Changes made
public var changes = [Change]()
/// Should formatter track changes?
public var trackChanges = false
private func trackChange(at index: Int) {
guard trackChanges, let rule = currentRule else { return }
changes.append(Change(
line: originalLine(at: index),
rule: rule,
filePath: options.fileInfo.filePath
))
}
private func updateRange(at index: Int, delta: Int) {
guard let range = range, range.contains(index) else {
return
}
self.range = range.lowerBound ..< range.upperBound + delta
}
// MARK: access and mutation
/// Returns the token at the specified index, or nil if index is invalid
public func token(at index: Int) -> Token? {
guard index >= 0, index < tokens.count else { return nil }
return tokens[index]
}
/// Replaces the token at the specified index with one or more new tokens
public func replaceToken(at index: Int, with tokens: Token...) {
if tokens.isEmpty {
removeToken(at: index)
} else if tokens.count != 1 || tokens[0] != self.tokens[index] {
trackChange(at: index)
self.tokens[index] = tokens[0]
for (i, token) in tokens.dropFirst().enumerated() {
insertToken(token, at: index + i + 1)
}
}
}
/// Replaces the tokens in the specified range with new tokens
public func replaceTokens(inRange range: Range<Int>, with tokens: [Token]) {
if range.count == tokens.count, ArraySlice(tokens) == self.tokens[range] {
return
}
let max = min(range.count, tokens.count)
for i in 0 ..< max {
trackChange(at: range.lowerBound + i)
self.tokens[range.lowerBound + i] = tokens[i]
}
if range.count > max {
for _ in max ..< range.count {
removeToken(at: range.lowerBound + max)
}
} else {
for i in max ..< tokens.count {
insertToken(tokens[i], at: range.lowerBound + i)
}
}
}
/// Replaces the tokens in the specified closed range with new tokens
public func replaceTokens(inRange range: ClosedRange<Int>, with tokens: [Token]) {
replaceTokens(inRange: range.lowerBound ..< range.upperBound + 1, with: tokens)
}
/// Removes the token at the specified index
public func removeToken(at index: Int) {
trackChange(at: index)
updateRange(at: index, delta: -1)
tokens.remove(at: index)
if enumerationIndex >= index {
enumerationIndex -= 1
}
}
/// Removes the tokens in the specified range
public func removeTokens(inRange range: Range<Int>) {
replaceTokens(inRange: range, with: [])
}
/// Removes the tokens in the specified closed range
public func removeTokens(inRange range: ClosedRange<Int>) {
replaceTokens(inRange: range, with: [])
}
/// Removes the last token
public func removeLastToken() {
trackChange(at: tokens.endIndex - 1)
updateRange(at: tokens.endIndex - 1, delta: -1)
tokens.removeLast()
}
/// Inserts an array of tokens at the specified index
public func insertTokens(_ tokens: [Token], at index: Int) {
trackChange(at: index)
for token in tokens.reversed() {
updateRange(at: index, delta: 1)
self.tokens.insert(token, at: index)
}
if enumerationIndex >= index {
enumerationIndex += tokens.count
}
}
/// Inserts a single token at the specified index
public func insertToken(_ token: Token, at index: Int) {
insertTokens([token], at: index)
}
// MARK: enumeration
/// Loops through each token in the array. It is safe to mutate the token
/// array inside the body block, but note that the index and token arguments
/// may not reflect the current token any more after a mutation
public func forEachToken(_ body: (Int, Token) -> Void) {
assert(enumerationIndex == -1, "forEachToken does not support re-entrancy")
enumerationIndex = 0
while enumerationIndex < tokens.count {
let token = tokens[enumerationIndex]
switch token {
case let .commentBody(comment):
processCommentBody(comment)
case .linebreak:
processLinebreak()
default:
break
}
if isEnabled {
body(enumerationIndex, token) // May mutate enumerationIndex
}
enumerationIndex += 1
}
enumerationIndex = -1
}
/// As above, but only loops through tokens that match the specified filter block
public func forEachToken(where matching: (Token) -> Bool, _ body: (Int, Token) -> Void) {
forEachToken { index, token in
if matching(token) {
body(index, token)
}
}
}
/// As above, but only loops through tokens with the specified type and string
public func forEach(_ token: Token, _ body: (Int, Token) -> Void) {
forEachToken(where: { $0 == token }, body)
}
/// As above, but only loops through tokens with the specified type and string
public func forEach(_ type: TokenType, _ body: (Int, Token) -> Void) {
forEachToken(where: { $0.is(type) }, body)
}
// MARK: utilities
/// Returns the index of the next token in the specified range that matches the block
public func index(in range: CountableRange<Int>, where matches: (Token) -> Bool) -> Int? {
let range = range.clamped(to: 0 ..< tokens.count)
var scopeStack: [Token] = []
for i in range {
let token = tokens[i]
// TODO: find a better way to deal with this special case
if token == .endOfScope("#endif") {
while let scope = scopeStack.last, scope != .startOfScope("#if") {
scopeStack.removeLast()
}
}
if let scope = scopeStack.last, token.isEndOfScope(scope) {
scopeStack.removeLast()
if case .linebreak = token, scopeStack.isEmpty, matches(token) {
return i
}
} else if token == .endOfScope("case") || token == .endOfScope("default"),
scopeStack.last == .startOfScope("#if") {
continue
} else if scopeStack.isEmpty, matches(token) {
return i
} else if token.isEndOfScope {
return nil
} else if case .startOfScope = token {
scopeStack.append(token)
}
}
return nil
}
/// Returns the index of the next token at the current scope that matches the block
public func index(after index: Int, where matches: (Token) -> Bool) -> Int? {
guard index < tokens.count else { return nil }
return self.index(in: index + 1 ..< tokens.count, where: matches)
}
/// Returns the index of the next matching token in the specified range
public func index(of token: Token, in range: CountableRange<Int>) -> Int? {
return index(in: range, where: { $0 == token })
}
/// Returns the index of the next matching token at the current scope
public func index(of token: Token, after index: Int) -> Int? {
return self.index(after: index, where: { $0 == token })
}
/// Returns the index of the next token in the specified range of the specified type
public func index(of type: TokenType, in range: CountableRange<Int>, if matches: (Token) -> Bool = { _ in true }) -> Int? {
return index(in: range, where: { $0.is(type) }).flatMap { matches(tokens[$0]) ? $0 : nil }
}
/// Returns the index of the next token at the current scope of the specified type
public func index(of type: TokenType, after index: Int, if matches: (Token) -> Bool = { _ in true }) -> Int? {
return self.index(after: index, where: { $0.is(type) }).flatMap { matches(tokens[$0]) ? $0 : nil }
}
/// Returns the next token at the current scope that matches the block
public func nextToken(after index: Int, where matches: (Token) -> Bool = { _ in true }) -> Token? {
return self.index(after: index, where: matches).map { tokens[$0] }
}
/// Returns the next token at the current scope of the specified type
public func next(_ type: TokenType, after index: Int, if matches: (Token) -> Bool = { _ in true }) -> Token? {
return self.index(of: type, after: index, if: matches).map { tokens[$0] }
}
/// Returns the next token in the specified range of the specified type
public func next(_ type: TokenType, in range: CountableRange<Int>, if matches: (Token) -> Bool = { _ in true }) -> Token? {
return index(of: type, in: range, if: matches).map { tokens[$0] }
}
/// Returns the index of the last token in the specified range that matches the block
public func lastIndex(in range: CountableRange<Int>, where matches: (Token) -> Bool) -> Int? {
let range = range.clamped(to: 0 ..< tokens.count)
var linebreakEncountered = false
var scopeStack: [Token] = []
for i in range.reversed() {
let token = tokens[i]
if case .startOfScope = token {
if let scope = scopeStack.last, scope.isEndOfScope(token) {
scopeStack.removeLast()
} else if token.string == "//", linebreakEncountered {
linebreakEncountered = false
} else if matches(token) {
return i
} else if token.string == "//", self.token(at: range.upperBound)?.isLinebreak == true {
continue
} else {
return nil
}
} else if scopeStack.isEmpty, matches(token) {
return i
} else if case .linebreak = token {
linebreakEncountered = true
} else if case .endOfScope = token {
scopeStack.append(token)
}
}
return nil
}
/// Returns the index of the previous token at the current scope that matches the block
public func index(before index: Int, where matches: (Token) -> Bool) -> Int? {
guard index > 0 else { return nil }
return lastIndex(in: 0 ..< index, where: matches)
}
/// Returns the index of the last matching token in the specified range
public func lastIndex(of token: Token, in range: CountableRange<Int>) -> Int? {
return lastIndex(in: range, where: { $0 == token })
}
/// Returns the index of the previous matching token at the current scope
public func index(of token: Token, before index: Int) -> Int? {
return self.index(before: index, where: { $0 == token })
}
/// Returns the index of the last token in the specified range of the specified type
public func lastIndex(of type: TokenType, in range: CountableRange<Int>, if matches: (Token) -> Bool = { _ in true }) -> Int? {
return lastIndex(in: range, where: { $0.is(type) }).flatMap { matches(tokens[$0]) ? $0 : nil }
}
/// Returns the index of the previous token at the current scope of the specified type
public func index(of type: TokenType, before index: Int, if matches: (Token) -> Bool = { _ in true }) -> Int? {
return self.index(before: index, where: { $0.is(type) }).flatMap { matches(tokens[$0]) ? $0 : nil }
}
/// Returns the previous token at the current scope that matches the block
public func lastToken(before index: Int, where matches: (Token) -> Bool) -> Token? {
return self.index(before: index, where: matches).map { tokens[$0] }
}
/// Returns the previous token at the current scope of the specified type
public func last(_ type: TokenType, before index: Int, if matches: (Token) -> Bool = { _ in true }) -> Token? {
return self.index(of: type, before: index, if: matches).map { tokens[$0] }
}
/// Returns the previous token in the specified range of the specified type
public func last(_ type: TokenType, in range: CountableRange<Int>, if matches: (Token) -> Bool = { _ in true }) -> Token? {
return lastIndex(of: type, in: range, if: matches).map { tokens[$0] }
}
/// Inserts a linebreak at the specified index
public func insertLinebreak(at index: Int) {
insertToken(linebreakToken(for: index), at: index)
}
/// Indicates if the given range contains any nontokens other than those allowed.
///
/// - Note: The range does not need to include the given tokens to return `true`,
/// it just can't include any unallowed tokens.
///
/// - Parameters:
/// - range: The range to check
/// - allowedTokens: The only tokens allowed in the range
/// - allowingWhitespaceAndComments:If spaces, linebreaks, and comments should also be allowed.
public func range(_ range: CountableRange<Int>,
doesNotContainsTokensExcept allowedTokens: [Token],
allowingWhitespaceAndComments: Bool) -> Bool {
let range = range.clamped(to: 0 ..< tokens.count)
for token in tokens[range] {
if allowedTokens.contains(token) ||
(allowingWhitespaceAndComments && token.isSpaceOrCommentOrLinebreak) {
continue
}
return false
}
return true
}
/// Returns the starting token for the containing scope at the specified index
public func currentScope(at index: Int) -> Token? {
return last(.startOfScope, before: index)
}
/// Returns the index of the ending token for the current scope
// TODO: should this return the closing `}` for `switch { ...` instead of nested `case`?
public func endOfScope(at index: Int) -> Int? {
var startIndex: Int
guard var startToken = token(at: index) else { return nil }
if case .startOfScope = startToken {
startIndex = index
} else if let index = self.index(of: .startOfScope, before: index) {
startToken = tokens[index]
startIndex = index
} else {
return nil
}
guard startToken == .startOfScope("{") else {
return self.index(after: startIndex, where: {
$0.isEndOfScope(startToken)
})
}
while let endIndex = self.index(after: startIndex, where: {
$0.isEndOfScope(startToken)
}), let token = token(at: endIndex) {
if token == .endOfScope("}") {
return endIndex
}
startIndex = endIndex
startToken = token
}
return nil
}
/// Either modifies or removes the existing space token at the specified
/// index, or inserts a new one if there is not already a space token present.
/// Returns the number of tokens inserted or removed
@discardableResult func insertSpace(_ space: String, at index: Int) -> Int {
if token(at: index)?.isSpace == true {
if space.isEmpty {
removeToken(at: index)
return -1 // Removed 1 token
}
replaceToken(at: index, with: .space(space))
} else if !space.isEmpty {
insertToken(.space(space), at: index)
return 1 // Inserted 1 token
}
return 0 // Inserted 0 tokens
}
/// Returns the original line number at the specified index
public func originalLine(at index: Int) -> OriginalLine {
for token in tokens[0 ..< index].reversed() {
if case let .linebreak(_, line) = token {
return line + 1
}
}
return 1
}
/// Returns a linebreak token suitable for insertion at the specified index
public func linebreakToken(for index: Int) -> Token {
let lineNumber: Int
if case let .linebreak(_, index)? = token(at: index) {
lineNumber = index
} else {
lineNumber = originalLine(at: index)
}
return .linebreak(options.linebreak, lineNumber)
}
/// Returns the index where the `wrap` rule should add the next linebreak in the line at the selected index.
///
/// If the line does not need to be wrapped, this will return `nil`.
///
/// - Note: This checks the entire line from the start of the line, the linebreak may be an index preceding the
/// `index` passed to the function.
func indexWhereLineShouldWrapInLine(at index: Int) -> Int? {
return indexWhereLineShouldWrap(from: startOfLine(at: index))
}
func indexWhereLineShouldWrap(from index: Int) -> Int? {
var lineLength = self.lineLength(upTo: index)
var stringLiteralDepth = 0
var currentPriority = 0
var lastBreakPoint: Int?
var lastBreakPointPriority = Int.min
let maxWidth = options.maxWidth
guard maxWidth > 0 else { return nil }
func addBreakPoint(at i: Int, relativePriority: Int) {
guard stringLiteralDepth == 0, currentPriority + relativePriority >= lastBreakPointPriority,
!isInClosureArguments(at: i + 1) else {
return
}
let i = self.index(of: .nonSpace, before: i + 1) ?? i
if token(at: i + 1)?.isLinebreak == true || token(at: i)?.isLinebreak == true {
return
}
lastBreakPoint = i
lastBreakPointPriority = currentPriority + relativePriority
}
let tokens = self.tokens[index ..< endOfLine(at: index)]
for (i, token) in zip(tokens.indices, tokens) {
switch token {
case .linebreak:
return nil
case .delimiter(","):
addBreakPoint(at: i, relativePriority: 0)
case .operator("=", .infix) where self.token(at: i + 1)?.isSpace == true:
addBreakPoint(at: i, relativePriority: -9)
case .operator(".", .infix):
addBreakPoint(at: i - 1, relativePriority: -2)
case .operator("->", .infix):
if isInReturnType(at: i) {
currentPriority -= 5
}
addBreakPoint(at: i - 1, relativePriority: -5)
case .operator(_, .infix) where self.token(at: i + 1)?.isSpace == true:
addBreakPoint(at: i, relativePriority: -3)
case .startOfScope("{"):
if !isStartOfClosure(at: i) ||
next(.keyword, after: i) != .keyword("in"),
next(.nonSpace, after: i) != .endOfScope("}") {
addBreakPoint(at: i, relativePriority: -6)
}
if isInReturnType(at: i) {
currentPriority += 5
}
currentPriority -= 6
case .endOfScope("}"):
currentPriority += 6
if last(.nonSpace, before: i) != .startOfScope("{") {
addBreakPoint(at: i - 1, relativePriority: -6)
}
case .startOfScope("("):
currentPriority -= 7
case .endOfScope(")"):
currentPriority += 7
case .startOfScope("["):
currentPriority -= 8
case .endOfScope("]"):
currentPriority += 8
case .startOfScope("<"):
currentPriority -= 9
case .endOfScope(">"):
currentPriority += 9
case .startOfScope where token.isStringDelimiter:
stringLiteralDepth += 1
case .endOfScope where token.isStringDelimiter:
stringLiteralDepth -= 1
case .keyword("else"), .keyword("where"):
addBreakPoint(at: i - 1, relativePriority: -1)
case .keyword("in"):
if last(.keyword, before: i) == .keyword("for") {
addBreakPoint(at: i, relativePriority: -11)
break
}
addBreakPoint(at: i, relativePriority: -5 - currentPriority)
default:
break
}
lineLength += tokenLength(token)
if lineLength > maxWidth, let breakPoint = lastBreakPoint, breakPoint < i {
return breakPoint
}
}
return nil
}
}