Commit `2cb9910daf`

2cb9910daf496bc213dbf10762f4e94f28afce82

parent: 1f40d56d3e

Verified · cmc

cmc <hello@cleberg.net> · 2026-10-05 03:42 UTC

Add document buffers

Layout: unified · split

Sources/OrgDocument/Buffer.swift added +24

@@ -0,0 +1,24 @@
	1	import Foundation
	2
	3	/// Where an open document's live state is kept: the editor while one shows it, a
	4	/// `StateBuffer` before that.
	5	@MainActor
	6	public protocol DocumentBuffer: AnyObject {
	7	var document: DocumentState { get }
	8	/// Applies a change made outside typing (save, disk change, revert) and updates whatever
	9	/// shows the document.
	10	func update<T>(_ change: (inout DocumentState) throws -> T) rethrows -> T
	11	}
	12
	13	@MainActor
	14	public final class StateBuffer: DocumentBuffer {
	15	public private(set) var document: DocumentState
	16
	17	public init(_ document: DocumentState) {
	18	self.document = document
	19	}
	20
	21	public func update<T>(_ change: (inout DocumentState) throws -> T) rethrows -> T {
	22	try change(&document)
	23	}
	24	}

Sources/OrgDocument/Saving.swift +10

	@@ -78,4 +78,14 @@ public struct Saver: Sendable {
78	}	78	}
79	throw SaveError.fileKeepsChanging	79	throw SaveError.fileKeepsChanging
80	}	80	}
		81
		82	/// Writes the buffer over whatever is on disk, for keeping our version over a conflicting
		83	/// one. The replaced version goes to recovery unless it is the merge base.
		84	public func overwrite(_ state: inout DocumentState, to url: URL) throws {
		85	let bytes = try state.encodedText()
		86	if let replaced = try fileSystem.replace(url, with: bytes), replaced != state.mergeBase {
		87	try recovery.keep(replaced, for: url, label: "external")
		88	}
		89	state.didWrite(bytes)
		90	}
81	}	91	}

Sources/OrgEditorAppKit/OrgEditor.swift +34 −20

     // MARK: - Saving
-    /// Saves through `saver`. When a merge changes the buffer, the text view is reloaded and
+    /// Saves through `saver`. A merge that changes the buffer reloads the text view.
-    /// folds are mapped through the change.
     @discardableResult
     public func save(using saver: Saver, to url: URL) throws -> SaveOutcome {
-        let before = document.text
+        try update { try saver.save(&$0, to: url) }
-        let outcome = try saver.save(&document, to: url)
-        if document.text != before {
-            let edits = lineEdits(from: before, to: document.text)
-            load(document.text)
-            let mapped = view.mapped(through: edits)
-            setFolds(FoldState(folds: mapped.folds, bodyFolds: mapped.bodyFolds))
-        }
-        return outcome
     }
+    /// Called after every change to the document, typed or not.
+    public var onChange: (() -> Void)?
     // MARK: - Commands
     /// Called with messages commands report, such as why one couldn't run here.
     /// The file on disk now holds `bytes`: reload or merge, keeping folds where the text kept
     /// its headings.
-    public func diskChanged(to bytes: [UInt8]) {
+    @discardableResult
-        let edits: [TextEdit]
+    public func diskChanged(to bytes: [UInt8]) -> DocumentState.ExternalChange {
-        switch document.diskChanged(to: bytes) {
+        update { $0.diskChanged(to: bytes) }
-        case .reloaded(let changes), .merged(let changes): edits = changes
-        case .unchanged, .conflict: return
-        }
-        let mapped = view.mapped(through: edits)
-        load(document.text)
-        setFolds(FoldState(folds: mapped.folds, bodyFolds: mapped.bodyFolds))
     }
     // MARK: - Folding
             textLayoutManager.invalidateLayout(for: textLayoutManager.documentRange)
         }
         onEditTiming?(clock.now - start)
+        onChange?()
     }
     /// Columns a wrapped continuation of `line` should start past the line's own start.
     }
 }
+extension OrgEditor: DocumentBuffer {
+    /// Runs `change`; if it changed the text, reloads the view with folds and the selection
+    /// mapped through the change. Text-view undo refers to the old text, so it is cleared.
+    public func update<T>(_ change: (inout DocumentState) throws -> T) rethrows -> T {
+        let before = document.text
+        let selected = textView.selectedRange()
+        let result = try change(&document)
+        if document.text != before {
+            let edits = lineEdits(from: before, to: document.text)
+            var state = view
+            state.selection = [selected.location..<NSMaxRange(selected)]
+            let mapped = state.mapped(through: edits)
+            load(document.text)
+            setFolds(FoldState(folds: mapped.folds, bodyFolds: mapped.bodyFolds))
+            let selection = mapped.selection[0]
+            setCaret(selection.lowerBound)
+            if !selection.isEmpty { textView.setSelectedRange(NSRange(selection)) }
+            textView.undoManager?.removeAllActions(withTarget: textView.textStorage!)
+            textView.undoManager?.removeAllActions(withTarget: textView)
+        }
+        onChange?()
+        return result
+    }
+}
 extension OrgEditor: NSTextViewDelegate {
     public func textView(_ textView: NSTextView, doCommandBy selector: Selector) -> Bool {
         switch selector {

Tests/OrgDocumentTests/SaveTests.swift +10

	@@ -103,6 +103,16 @@ struct SaveTests {
103	#expect(doc.text == "A\nb\nc\n")	103	#expect(doc.text == "A\nb\nc\n")
104	}	104	}
105		105
		106	@Test func overwriteKeepsTheReplacedVersion() throws {
		107	let files = FaultyFileSystem("Z\nb\nc\n")
		108	let recovery = MemoryRecovery()
		109	var doc = try editedState()
		110	try Saver(fileSystem: files, recovery: recovery).overwrite(&doc, to: url)
		111	#expect(files.text == "A\nb\nc\n")
		112	#expect(!doc.isDirty)
		113	#expect(recovery.contains("Z\nb\nc\n"))
		114	}
		115
106	@Test func changedBetweenReadAndCheckRetries() throws {	116	@Test func changedBetweenReadAndCheckRetries() throws {
107	let files = FaultyFileSystem("a\nb\nc\n")	117	let files = FaultyFileSystem("a\nb\nc\n")
108	files.beforeRead[2] = Array("a\nb\nC\n".utf8)	118	files.beforeRead[2] = Array("a\nb\nC\n".utf8)

Tests/OrgEditorAppKitTests/EditorTests.swift +23

	@@ -229,6 +229,29 @@ struct EditingTests {
229	}	229	}
230	}	230	}
231		231
		232	@MainActor
		233	struct BufferTests {
		234	@Test func updateMapsCaretAndFoldsAndClearsUndo() {
		235	let h = Harness(outline)
		236	var changes = 0
		237	h.editor.onChange = { changes += 1 }
		238	h.caret(at: 1)
		239	h.textView.insertText("x", replacementRange: NSRange(location: 4, length: 0))
		240	#expect(changes == 1)
		241	RunLoop.current.run(until: Date())
		242	#expect(h.textView.undoManager?.canUndo == true)
		243	h.editor.setFolds(FoldState(folds: [h.offset(of: "** b")]))
		244	h.caret(at: h.offset(of: "* c") + 2)
		245	h.editor.update { $0 = DocumentState(bytes: Array(("new\n" + outline).utf8)) }
		246	#expect(changes == 2)
		247	#expect(h.string == "new\n" + outline)
		248	#expect(h.caret == h.offset(of: "* c") + 2)
		249	#expect(h.editor.foldState.folds == [h.offset(of: "** b")])
		250	#expect(h.textView.undoManager?.canUndo != true)
		251	h.checkInSync()
		252	}
		253	}
		254
232	@MainActor	255	@MainActor
233	struct RestyleTests {	256	struct RestyleTests {
234	func indent(_ h: Harness, at line: String) -> CGFloat? {	257	func indent(_ h: Harness, at line: String) -> CGFloat? {

docs/plans/2026-10-05-writable-app.md +6 −6

	@@ -28,7 +28,7 @@
28	\| File \| Responsibility \|	28	\| File \| Responsibility \|
29	\| --- \| --- \|	29	\| --- \| --- \|
30	\| `Sources/OrgDocument/Buffer.swift` \| `DocumentBuffer`, `StateBuffer` \|	30	\| `Sources/OrgDocument/Buffer.swift` \| `DocumentBuffer`, `StateBuffer` \|
31	\| `Sources/OrgDocument/DocumentState.swift` \| `rebase(onto:)` \|	31	\| `Sources/OrgDocument/Saving.swift` \| `Saver.overwrite(_:to:)` \|
32	\| `Sources/OrgEditorAppKit/OrgEditor.swift` \| `DocumentBuffer` conformance: `update(_:)` maps folds and caret and clears text-view undo when the text is replaced; `onChange` \|	32	\| `Sources/OrgEditorAppKit/OrgEditor.swift` \| `DocumentBuffer` conformance: `update(_:)` maps folds and caret and clears text-view undo when the text is replaced; `onChange` \|
33	\| `Sources/OrgApp/DocumentSession.swift` \| Buffer, dirty flag, save, autosave, conflict choices, `SaveMode` \|	33	\| `Sources/OrgApp/DocumentSession.swift` \| Buffer, dirty flag, save, autosave, conflict choices, `SaveMode` \|
34	\| `Sources/OrgApp/WorkspaceModel.swift` \| `overlay(path:document:)` \|	34	\| `Sources/OrgApp/WorkspaceModel.swift` \| `overlay(path:document:)` \|
	@@ -38,7 +38,7 @@
38		38
39	### Task 1: Buffers	39	### Task 1: Buffers
40		40
41	Files: `Sources/OrgDocument/Buffer.swift`, `Sources/OrgDocument/DocumentState.swift`, `Sources/OrgEditorAppKit/OrgEditor.swift`, `Tests/OrgDocumentTests/DocumentStateTests.swift`, `Tests/OrgEditorAppKitTests/EditorTests.swift`	41	Files: `Sources/OrgDocument/Buffer.swift`, `Sources/OrgDocument/Saving.swift`, `Sources/OrgEditorAppKit/OrgEditor.swift`, `Tests/OrgDocumentTests/DocumentStateTests.swift`, `Tests/OrgEditorAppKitTests/EditorTests.swift`
42		42
43	Produces:	43	Produces:
44		44
	@@ -53,9 +53,9 @@ public protocol DocumentBuffer: AnyObject {
53	@MainActor	53	@MainActor
54	public final class StateBuffer: DocumentBuffer { public init(_ document: DocumentState) }	54	public final class StateBuffer: DocumentBuffer { public init(_ document: DocumentState) }
55		55
56	extension DocumentState {	56	extension Saver {
57	/// Makes `bytes` the merge base and keeps the text, so the next save replaces them.	57	/// Writes the buffer over whatever is on disk; the replaced version goes to recovery.
58	public mutating func rebase(onto bytes: [UInt8])	58	public func overwrite(_ state: inout DocumentState, to url: URL) throws
59	}	59	}
60		60
61	extension OrgEditor: DocumentBuffer // plus `public var onChange: (() -> Void)?`	61	extension OrgEditor: DocumentBuffer // plus `public var onChange: (() -> Void)?`
	@@ -63,7 +63,7 @@ extension OrgEditor: DocumentBuffer // plus `public var onChange: (() -> Void)
63		63
64	`OrgEditor.update` records the text and selection, runs the change, and if the text changed: computes `lineEdits(from:to:)`, reloads the storage, maps folds and the selection through the edits, and removes the text view's undo actions (they refer to the old text). `save(using:to:)` and `diskChanged(to:)` become `update` calls; `diskChanged` returns the `ExternalChange`.	64	`OrgEditor.update` records the text and selection, runs the change, and if the text changed: computes `lineEdits(from:to:)`, reloads the storage, maps folds and the selection through the edits, and removes the text view's undo actions (they refer to the old text). `save(using:to:)` and `diskChanged(to:)` become `update` calls; `diskChanged` returns the `ExternalChange`.
65		65
66	- [ ] Tests: `rebase` keeps text and makes the buffer dirty against new bytes; editor `update` replacing text keeps the caret on the same line content, keeps folds, and leaves nothing to undo; typing calls `onChange`.	66	- [ ] Tests: `overwrite` writes ours and keeps the replaced version; editor `update` replacing text keeps the caret on the same line content, keeps folds, and leaves nothing to undo; typing calls `onChange`.
67	- [ ] Implement; `swift test` green.	67	- [ ] Implement; `swift test` green.
68	- [ ] Commit "Add document buffers".	68	- [ ] Commit "Add document buffers".
69		69

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