krz/orgstar

A native macOS editor for org-mode files. editor org-mode swift

Sources/OrgCore/Commands/HeadingCommands.swift

176fc78498d9ba962fa963bbeca0dd433d9e0bab
orgstar/Sources/OrgCore/Commands/HeadingCommands.swift history · blame · raw

374 lines · 17299 bytes

  1import Foundation
  2
  3// Heading-line commands, matched to Emacs 31.1 / Org 9.8.7 by the oracle tests.
  4
  5/// The heading whose line holds `offset`, for commands that act only on heading lines (org's
  6/// M-left, M-right, S-up and S-down do something else elsewhere).
  7func headingOnLine(at offset: Int, in tree: OrgTree) -> SyntaxNode? {
  8    guard let heading = entryHeading(at: offset, in: tree) else { return nil }
  9    let line = HeadingLine(heading)
 10    return offset >= line.start && offset <= line.contentEnd ? heading : nil
 11}
 12
 13/// The heading of the entry holding `offset`, as `org-back-to-heading`; nil before the first
 14/// heading.
 15func entryHeading(at offset: Int, in tree: OrgTree) -> SyntaxNode? {
 16    let root = tree.root
 17    let position = offset >= root.range.upperBound ? max(0, root.range.upperBound - 1) : offset
 18    var node = root
 19    var heading: SyntaxNode?
 20    while let child = node.child(containing: position), child.kind == .section {
 21        heading = child.firstChild(.heading)
 22        node = child
 23    }
 24    return heading
 25}
 26
 27/// The parts of a heading line, in offsets of the whole text.
 28struct HeadingLine {
 29    let start: Int
 30    /// End of the line's content, before its line break.
 31    let contentEnd: Int
 32    let stars: Range<Int>
 33    let todo: SyntaxToken?
 34    let priority: SyntaxToken?
 35    let tags: SyntaxToken?
 36    /// Where the title begins: past the stars, keyword, cookie and the blanks after them.
 37    let titleStart: Int
 38
 39    init(_ heading: SyntaxNode) {
 40        let tokens = heading.tokens
 41        start = heading.range.lowerBound
 42        contentEnd = tokens.first { $0.kind == .newline }?.range.lowerBound ?? heading.range.upperBound
 43        stars = tokens.first { $0.kind == .stars }?.range ?? start..<start
 44        todo = tokens.first { $0.kind == .todoKeyword }
 45        priority = tokens.first { $0.kind == .priority }
 46        tags = tokens.first { $0.kind == .tags }
 47        var at = start
 48        for child in heading.green.children {
 49            guard case .token(let token) = child, [.stars, .whitespace, .todoKeyword, .priority].contains(token.kind) else { break }
 50            at += token.length
 51        }
 52        titleStart = min(at, contentEnd)
 53    }
 54
 55    var level: Int { stars.count }
 56}
 57
 58/// One line of text being edited, with a caret that moves the way Emacs moves point and
 59/// markers for each kind of edit, so commands land the caret where Emacs does.
 60struct LineBuffer {
 61    var text: NSMutableString
 62    /// Relative to the line start; nil when the caret is elsewhere in the document.
 63    var caret: Int?
 64
 65    init(_ line: String, caret: Int?) {
 66        text = NSMutableString(string: line)
 67        self.caret = caret
 68    }
 69
 70    var string: String { text as String }
 71    var length: Int { text.length }
 72
 73    private mutating func edit(_ range: Range<Int>, _ replacement: String) -> Int {
 74        text.replaceCharacters(in: NSRange(range), with: replacement)
 75        return (replacement as NSString).length - range.count
 76    }
 77
 78    /// `replace-match`: a caret strictly inside moves to the start; at or after the end it
 79    /// shifts with the text.
 80    mutating func replace(_ range: Range<Int>, with replacement: String) {
 81        let delta = edit(range, replacement)
 82        guard let position = caret else { return }
 83        if position >= range.upperBound, position > range.lowerBound {
 84            caret = position + delta
 85        } else if position > range.lowerBound {
 86            caret = range.lowerBound
 87        }
 88    }
 89
 90    /// Deleting `range`, then `insert-before-markers`: a caret anywhere from the start to the
 91    /// end of the range ends up after the new text.
 92    mutating func replaceBeforeMarkers(_ range: Range<Int>, with replacement: String) {
 93        let delta = edit(range, replacement)
 94        guard let position = caret else { return }
 95        if position > range.upperBound {
 96            caret = position + delta
 97        } else if position >= range.lowerBound {
 98            caret = range.lowerBound + (replacement as NSString).length
 99        }
100    }
101
102    /// `insert` under `save-excursion`: a caret at the insertion point stays before the text.
103    mutating func insert(_ string: String, at position: Int) {
104        let delta = edit(position..<position, string)
105        if let caret, caret > position { self.caret = caret + delta }
106    }
107
108    /// `insert` at point: the caret moves past the text.
109    mutating func insertAtCaret(_ string: String) {
110        guard let position = caret else { return }
111        let delta = edit(position..<position, string)
112        caret = position + delta
113    }
114}
115
116extension HeadingLine {
117    /// Applies `edit` to the heading line in `context` and maps the caret: on the line it's
118    /// placed by `edit`; after the line it shifts by the change in length.
119    func commit(_ context: EditContext, _ edit: (inout LineBuffer) -> Void) -> CommandStep {
120        let old = (context.text as NSString).substring(with: NSRange(start..<contentEnd))
121        let caretOnLine = context.caret >= start && context.caret <= contentEnd
122        var buffer = LineBuffer(old, caret: caretOnLine ? context.caret - start : nil)
123        edit(&buffer)
124        let new = buffer.string
125        let delta = (new as NSString).length - (old as NSString).length
126        let caret = buffer.caret.map { $0 + start } ?? (context.caret > contentEnd ? context.caret + delta : context.caret)
127        guard new != old else { return .commit(EditResult(baseRevision: context.revision, edits: [], selection: [caret..<caret])) }
128        return .commit(EditResult(
129            baseRevision: context.revision,
130            edits: [TextEdit(range: start..<contentEnd, replacement: new)],
131            selection: [caret..<caret]
132        ))
133    }
134
135    /// Offsets relative to the line start.
136    func local(_ range: Range<Int>) -> Range<Int> { (range.lowerBound - start)..<(range.upperBound - start) }
137}
138
139// MARK: - Tags
140
141/// `org--align-tags-here` with `org-tags-column` -77: tags end at column 77, or sit one blank
142/// after the title when it is too long. Nothing changes when they are already there.
143///
144/// Commands align under `save-excursion`, where the caret is a marker: in the blanks before
145/// the tags it ends up where they start. Aligning tags directly (`preservingColumn`) keeps the
146/// caret's column instead, as org does for point.
147func alignTags(_ buffer: inout LineBuffer, options: EditingOptions = .org, preservingColumn: Bool = false) {
148    let line = buffer.string
149    guard let match = line.range(of: "[ \\t]+(:[[:alnum:]_@#%]+)+:[ \\t]*$", options: .regularExpression) else { return }
150    let matched = String(line[match])
151    let tags = matched.trimmingCharacters(in: .whitespaces)
152    let blankStart = (String(line[..<match.lowerBound]) as NSString).length
153    let tagsStart = blankStart + (matched as NSString).range(of: tags).location
154    // Columns as Emacs displays the line: link markup and, with the options, emphasis markers
155    // don't count.
156    let visible = VisibleLine(line, options: options)
157    let prefixColumn = visible.column(at: blankStart)
158    let currentColumn = visible.column(at: tagsStart)
159    let tagsColumn = options.tagsColumn
160    let target = tagsColumn >= 0 ? tagsColumn : abs(tagsColumn) - displayWidth(tags)
161    let newColumn = max(target, prefixColumn + 1)
162    guard newColumn != currentColumn else { return }
163    let inBlanks = buffer.caret.map { $0 > blankStart && $0 <= tagsStart } ?? false
164    let caretColumn: Int? = inBlanks && preservingColumn ? visible.column(at: buffer.caret!) : nil
165    let old = buffer.caret
166    buffer.text.replaceCharacters(in: NSRange(blankStart..<tagsStart), with: String(repeating: " ", count: newColumn - prefixColumn))
167    let delta = (newColumn - prefixColumn) - (tagsStart - blankStart)
168    if let caretColumn {
169        buffer.caret = VisibleLine(buffer.string, options: options).offset(ofColumn: caretColumn)
170    } else if inBlanks {
171        buffer.caret = blankStart
172    } else if let old, old > tagsStart {
173        buffer.caret = old + delta
174    }
175}
176
177
178// MARK: - TODO
179
180public struct TodoCycle: OrgCommand {
181    public init() {}
182    public var id: String { "org.todo.cycle" }
183    public var title: String { "Cycle TODO State" }
184
185    public func applies(in context: EditContext) -> Bool {
186        entryHeading(at: context.caret, in: context.tree) != nil
187    }
188
189    /// No keyword, then each keyword of its sequence in order, then no keyword again.
190    static func next(after current: String?, in settings: OrgSettings) -> String? {
191        guard let current else {
192            guard let first = settings.todoSequences.first else { return nil }
193            return (first.active + first.done).first?.name
194        }
195        for sequence in settings.todoSequences {
196            let names = (sequence.active + sequence.done).map(\.name)
197            if let index = names.firstIndex(of: current) {
198                return index + 1 < names.count ? names[index + 1] : nil
199            }
200        }
201        return nil
202    }
203
204    /// As `org-todo`: the blanks after the stars, the keyword and the blanks after it are
205    /// replaced by " NEXT " (or " " for no keyword) with `insert-before-markers`, then tags
206    /// are aligned.
207    /// `org-todo`, then the parent's TODO statistics, and the repeat of a repeating entry
208    /// that became done.
209    public func run(in context: EditContext) -> CommandStep {
210        let previous = EmacsBuffer(context.text, point: context.caret, settings: context.tree.settings).todoKeyword
211        return followUp(context, cycle(in: context)) { buffer in
212            try buffer.saveExcursion {
213                buffer.updateParentTodoStatistics()
214                let settings = context.tree.settings
215                guard let new = buffer.todoKeyword, settings.isDone(new), !(previous.map(settings.isDone) ?? false) else { return }
216                if let (marker, note) = try buffer.autoRepeat(doneWord: new, previous: previous) { buffer.storeNote(marker, note) }
217            }
218        }
219    }
220
221    private func cycle(in context: EditContext) -> CommandStep {
222        guard let heading = entryHeading(at: context.caret, in: context.tree) else {
223            return .failed("Before first headline")
224        }
225        let line = HeadingLine(heading)
226        let next = Self.next(after: line.todo?.text, in: context.tree.settings)
227        return line.commit(context) { buffer in
228            let text = buffer.string as NSString
229            let regionStart = line.stars.upperBound - line.start
230            var regionEnd = regionStart
231            while regionEnd < text.length, text.character(at: regionEnd) == 0x20 { regionEnd += 1 }
232            if let todo = line.todo {
233                regionEnd = line.local(todo.range).upperBound
234                var blanks = regionEnd
235                while blanks < text.length, text.character(at: blanks) == 0x20 { blanks += 1 }
236                if blanks > regionEnd {
237                    regionEnd = blanks
238                } else if text.substring(from: regionEnd).allSatisfy({ $0 == " " || $0 == "\t" }) {
239                    regionEnd = text.length
240                }
241            }
242            buffer.replaceBeforeMarkers(regionStart..<regionEnd, with: next.map { " \($0) " } ?? " ")
243            alignTags(&buffer, options: context.options)
244        }
245    }
246}
247
248// MARK: - Priority
249
250struct PriorityChange {
251    let up: Bool
252
253    func run(in context: EditContext) -> CommandStep {
254        guard let heading = headingOnLine(at: context.caret, in: context.tree) else {
255            return .failed("Not on a heading")
256        }
257        let line = HeadingLine(heading)
258        let priorities = context.tree.settings.priorities
259        guard let highest = Self.value(priorities.highest), let lowest = Self.value(priorities.lowest) else {
260            return .failed("Unsupported priority range")
261        }
262        let numeric = Int(priorities.highest) != nil
263        let current = line.priority.flatMap { Self.value(String($0.text.dropFirst(2).dropLast())) }
264        // From no cookie, the first press sets the default, as `org-priority-start-cycle-with-default`.
265        var new: Int?
266        if let current {
267            new = up ? current - 1 : current + 1
268            if let value = new, value < highest || value > lowest { new = nil }
269        } else {
270            new = Self.value(priorities.default)
271        }
272        let cookie = new.map { "[#\(Self.label($0, numeric: numeric))]" }
273        return line.commit(context) { buffer in
274            if let existing = line.priority {
275                let range = line.local(existing.range)
276                if let cookie {
277                    buffer.replace((range.lowerBound + 2)..<(range.upperBound - 1), with: String(cookie.dropFirst(2).dropLast()))
278                } else {
279                    // The cookie and one following space, as `org-priority-regexp` group 1.
280                    let text = buffer.string as NSString
281                    let space = range.upperBound < text.length && text.character(at: range.upperBound) == 0x20 ? 1 : 0
282                    buffer.replace(range.lowerBound..<(range.upperBound + space), with: "")
283                }
284            } else if let cookie {
285                if let todo = line.todo {
286                    buffer.insert(" " + cookie, at: line.local(todo.range).upperBound)
287                } else {
288                    buffer.insert(cookie + " ", at: line.titleStart - line.start)
289                }
290            }
291            alignTags(&buffer, options: context.options)
292        }
293    }
294
295    /// A priority as a number: a letter's code point, or the number itself.
296    static func value(_ text: String) -> Int? {
297        if let number = Int(text) { return number }
298        guard text.unicodeScalars.count == 1, let scalar = text.unicodeScalars.first else { return nil }
299        return Int(scalar.value)
300    }
301
302    static func label(_ value: Int, numeric: Bool) -> String {
303        numeric ? String(value) : String(Character(Unicode.Scalar(UInt32(value))!))
304    }
305}
306
307public struct PriorityUp: OrgCommand {
308    public init() {}
309    public var id: String { "org.priority.up" }
310    public var title: String { "Raise Priority" }
311    public func applies(in context: EditContext) -> Bool { headingOnLine(at: context.caret, in: context.tree) != nil }
312    public func run(in context: EditContext) -> CommandStep { PriorityChange(up: true).run(in: context) }
313}
314
315public struct PriorityDown: OrgCommand {
316    public init() {}
317    public var id: String { "org.priority.down" }
318    public var title: String { "Lower Priority" }
319    public func applies(in context: EditContext) -> Bool { headingOnLine(at: context.caret, in: context.tree) != nil }
320    public func run(in context: EditContext) -> CommandStep { PriorityChange(up: false).run(in: context) }
321}
322
323// MARK: - Promote and demote
324
325public struct PromoteHeading: OrgCommand {
326    public init() {}
327    public var id: String { "org.heading.promote" }
328    public var title: String { "Promote Heading" }
329    public func applies(in context: EditContext) -> Bool { headingOnLine(at: context.caret, in: context.tree) != nil }
330
331    public func run(in context: EditContext) -> CommandStep {
332        guard let heading = headingOnLine(at: context.caret, in: context.tree) else { return .failed("Not on a heading") }
333        let line = HeadingLine(heading)
334        guard line.level > 1 else { return .failed("Cannot promote to level 0") }
335        return line.commit(context) { buffer in
336            buffer.replace(0..<(line.level + 1), with: String(repeating: "*", count: line.level - 1) + " ")
337            alignTags(&buffer, options: context.options)
338            fixPositionAfterPromote(&buffer, settings: context.tree.settings)
339        }
340    }
341}
342
343public struct DemoteHeading: OrgCommand {
344    public init() {}
345    public var id: String { "org.heading.demote" }
346    public var title: String { "Demote Heading" }
347    public func applies(in context: EditContext) -> Bool { headingOnLine(at: context.caret, in: context.tree) != nil }
348
349    public func run(in context: EditContext) -> CommandStep {
350        guard let heading = headingOnLine(at: context.caret, in: context.tree) else { return .failed("Not on a heading") }
351        let line = HeadingLine(heading)
352        return line.commit(context) { buffer in
353            buffer.replace(0..<(line.level + 1), with: String(repeating: "*", count: line.level + 1) + " ")
354            alignTags(&buffer, options: context.options)
355            fixPositionAfterPromote(&buffer, settings: context.tree.settings)
356        }
357    }
358}
359
360/// `org-fix-position-after-promote`: a caret right after the stars or the keyword steps over
361/// the following space, or adds one at the end of the line.
362func fixPositionAfterPromote(_ buffer: inout LineBuffer, settings: OrgSettings) {
363    guard let caret = buffer.caret else { return }
364    let tree = OrgParser.parse(buffer.string + "\n", defaults: settings)
365    guard let heading = tree.root.firstChild(.section)?.firstChild(.heading) else { return }
366    let line = HeadingLine(heading)
367    let anchors = [line.stars.upperBound, line.todo?.range.upperBound].compactMap { $0 }
368    guard anchors.contains(caret) else { return }
369    if caret == buffer.length {
370        buffer.insertAtCaret(" ")
371    } else if buffer.text.character(at: caret) == 0x20 {
372        buffer.caret = caret + 1
373    }
374}