From b665ce8ce71b277d18054adfdb794073db690591 Mon Sep 17 00:00:00 2001
From: "Timothy J. Warren" <tim@timshomepage.net>
Date: Wed, 22 Nov 2023 11:07:33 -0500
Subject: [PATCH] Basic deletion functionality

---
 src/common/all_test.ts | 46 ++++++++++++++++++++++++------------------
 src/common/ansi.ts     |  2 +-
 src/common/document.ts | 21 +++++++++++--------
 src/common/editor.ts   | 12 +++++++++--
 src/common/row.ts      | 19 ++++++++++++++++-
 5 files changed, 68 insertions(+), 32 deletions(-)

diff --git a/src/common/all_test.ts b/src/common/all_test.ts
index 88c5897..1aaab5c 100644
--- a/src/common/all_test.ts
+++ b/src/common/all_test.ts
@@ -18,6 +18,12 @@ const {
 	testSuite,
 } = await getTestRunner();
 
+const testKeyMap = (codes: string[], expected: string) => {
+	codes.forEach((code) => {
+		assertEquals(readKey(code), expected);
+	});
+};
+
 testSuite({
 	'ANSI::ANSI utils': {
 		'Ansi.moveCursor': () => {
@@ -39,27 +45,21 @@ testSuite({
 			assertEquals(readKey(KeyCommand.ArrowUp), KeyCommand.ArrowUp);
 			assertEquals(readKey(KeyCommand.Home), KeyCommand.Home);
 			assertEquals(readKey(KeyCommand.Delete), KeyCommand.Delete);
+
+			// And pass through whatever else
+			assertEquals(readKey('foobaz'), 'foobaz');
 		},
-		'readKey Esc': () => {
-			['\x1b', Util.ctrlKey('l')].forEach((code) => {
-				assertEquals(readKey(code), KeyCommand.Escape);
-			});
-		},
-		'readKey Backspace': () => {
-			[Util.ctrlKey('h'), String.fromCodePoint(127)].forEach((code) => {
-				assertEquals(readKey(code), KeyCommand.Backspace);
-			});
-		},
-		'readKey Home': () => {
-			['\x1b[1~', '\x1b[7~', '\x1b[H', '\x1bOH'].forEach((code) => {
-				assertEquals(readKey(code), KeyCommand.Home);
-			});
-		},
-		'readKey End': () => {
-			['\x1b[4~', '\x1b[8~', '\x1b[F', '\x1bOF'].forEach((code) => {
-				assertEquals(readKey(code), KeyCommand.End);
-			});
-		},
+		'readKey Esc': () =>
+			testKeyMap(['\x1b', Util.ctrlKey('l')], KeyCommand.Escape),
+		'readKey Backspace': () =>
+			testKeyMap(
+				[Util.ctrlKey('h'), '\x7f'],
+				KeyCommand.Backspace,
+			),
+		'readKey Home': () =>
+			testKeyMap(['\x1b[1~', '\x1b[7~', '\x1b[H', '\x1bOH'], KeyCommand.Home),
+		'readKey End': () =>
+			testKeyMap(['\x1b[4~', '\x1b[8~', '\x1b[F', '\x1bOF'], KeyCommand.End),
 	},
 	Buffer: {
 		'Buffer exists': () => {
@@ -137,6 +137,12 @@ testSuite({
 			assertEquals(doc.numRows, 2);
 			assertTrue(doc.dirty);
 		},
+		'Document.delete': () => {
+			const doc = Document.empty();
+			doc.insert(Position.default(), 'foobar');
+			doc.delete(Position.at(3, 0));
+			assertEquals(doc.row(0)?.toString(), 'fooar');
+		},
 	},
 	Editor: {
 		'new Editor': () => {
diff --git a/src/common/ansi.ts b/src/common/ansi.ts
index 6c7fd18..c6486fa 100644
--- a/src/common/ansi.ts
+++ b/src/common/ansi.ts
@@ -76,7 +76,7 @@ export function readKey(parsed: string): string {
 			return KeyCommand.Escape;
 
 		case ctrlKey('h'):
-		case String.fromCodePoint(127):
+		case '\x7f':
 			return KeyCommand.Backspace;
 
 		default:
diff --git a/src/common/document.ts b/src/common/document.ts
index 61b6588..15cc3d5 100644
--- a/src/common/document.ts
+++ b/src/common/document.ts
@@ -1,7 +1,6 @@
-import { chars } from './utils.ts';
 import Row from './row.ts';
 import { getRuntime } from './runtime.ts';
-import { Position, SCROLL_TAB_SIZE } from './mod.ts';
+import { Position } from './mod.ts';
 
 export class Document {
 	#filename: string | null;
@@ -61,12 +60,22 @@ export class Document {
 			this.appendRow(c);
 		} else {
 			this.#rows[at.y].insertChar(at.x, c);
-			this.updateRow(this.#rows[at.y]);
+			this.#rows[at.y].updateRender();
 		}
 
 		this.dirty = true;
 	}
 
+	public delete(at: Position): void {
+		const row = this.row(at.y);
+		if (row === null) {
+			return;
+		}
+
+		row.delete(at.x);
+		row.updateRender();
+	}
+
 	public row(i: number): Row | null {
 		return this.#rows[i] ?? null;
 	}
@@ -74,15 +83,11 @@ export class Document {
 	public appendRow(s: string): void {
 		const at = this.numRows;
 		this.#rows[at] = new Row(s);
-		this.updateRow(this.#rows[at]);
+		this.#rows[at].updateRender();
 
 		this.dirty = true;
 	}
 
-	private updateRow(r: Row): void {
-		r.render = chars(r.toString().replace('\t', ' '.repeat(SCROLL_TAB_SIZE)));
-	}
-
 	private rowsToString(): string {
 		return this.#rows.map((r) => r.toString()).join('\n');
 	}
diff --git a/src/common/editor.ts b/src/common/editor.ts
index 428a0e4..8e22843 100644
--- a/src/common/editor.ts
+++ b/src/common/editor.ts
@@ -113,9 +113,17 @@ class Editor {
 				}
 				break;
 
-			case KeyCommand.Backspace:
 			case KeyCommand.Delete:
-				// TODO
+				this.#document.delete(this.#cursor);
+				break;
+
+			case KeyCommand.Backspace:
+				{
+					if (this.#cursor.x > 0 || this.#cursor.y > 0) {
+						this.moveCursor(KeyCommand.ArrowLeft);
+						this.#document.delete(this.#cursor);
+					}
+				}
 				break;
 
 			case KeyCommand.PageUp:
diff --git a/src/common/row.ts b/src/common/row.ts
index 5b825d5..0d04532 100644
--- a/src/common/row.ts
+++ b/src/common/row.ts
@@ -1,4 +1,4 @@
-import { SCROLL_TAB_SIZE } from './mod.ts';
+import { chars, SCROLL_TAB_SIZE } from './mod.ts';
 import * as Util from './utils.ts';
 
 /**
@@ -44,6 +44,14 @@ export class Row {
 		}
 	}
 
+	public delete(at: number): void {
+		if (at >= this.size) {
+			return;
+		}
+
+		this.chars.splice(at, 1);
+	}
+
 	public cxToRx(cx: number): number {
 		let rx = 0;
 		let j = 0;
@@ -60,6 +68,15 @@ export class Row {
 	public toString(): string {
 		return this.chars.join('');
 	}
+
+	public updateRender(): void {
+		const newString = this.chars.join('').replace(
+			'\t',
+			' '.repeat(SCROLL_TAB_SIZE),
+		);
+
+		this.render = chars(newString);
+	}
 }
 
 export default Row;