From 1cfdeece603ac1458571548fd0154f915d1fe7ee Mon Sep 17 00:00:00 2001
From: "Timothy J. Warren" <tim@timshomepage.net>
Date: Fri, 5 Jul 2024 09:27:28 -0400
Subject: [PATCH] Make document.row getter return an option instead of a
 nullable

---
 src/common/all_test.ts |  8 ++++----
 src/common/document.ts | 12 +++++++++---
 src/common/editor.ts   | 35 +++++++++++++++++++----------------
 src/common/search.ts   |  4 ++--
 4 files changed, 34 insertions(+), 25 deletions(-)

diff --git a/src/common/all_test.ts b/src/common/all_test.ts
index 4834b0b..61d4e5f 100644
--- a/src/common/all_test.ts
+++ b/src/common/all_test.ts
@@ -323,10 +323,10 @@ const DocumentTest = {
 		doc.insert(Position.at(9, 0), 'buzz');
 		assertEquals(doc.numRows, 1);
 		assertTrue(doc.dirty);
-		const row0 = doc.row(0);
-		assertEquals(row0?.toString(), 'foobazbarbuzz');
-		assertEquals(row0?.rstring(), 'foobazbarbuzz');
-		assertEquals(row0?.rsize, 13);
+		const row0 = doc.row(0).unwrap();
+		assertEquals(row0.toString(), 'foobazbarbuzz');
+		assertEquals(row0.rstring(), 'foobazbarbuzz');
+		assertEquals(row0.rsize, 13);
 
 		doc.insert(Position.at(0, 1), 'Lorem Ipsum');
 		assertEquals(doc.numRows, 2);
diff --git a/src/common/document.ts b/src/common/document.ts
index e45fb82..5da15c7 100644
--- a/src/common/document.ts
+++ b/src/common/document.ts
@@ -145,7 +145,13 @@ export class Document {
 			return;
 		}
 
-		const row = this.row(at.y)!;
+		const maybeRow = this.row(at.y);
+		if (maybeRow.isNone()) {
+			return;
+		}
+
+		const row = maybeRow.unwrap();
+
 		const mergeNextRow = at.x === row.size && at.y + 1 < len;
 		const mergeIntoPrevRow = at.x === 0 && at.y > 0;
 
@@ -173,8 +179,8 @@ export class Document {
 		this.dirty = true;
 	}
 
-	public row(i: number): Row | null {
-		return this.#rows[i] ?? null;
+	public row(i: number): Option<Row> {
+		return Option.from(this.#rows[i]);
 	}
 
 	public insertRow(at: number = this.numRows, s: string = ''): void {
diff --git a/src/common/editor.ts b/src/common/editor.ts
index c5d6118..e8b7837 100644
--- a/src/common/editor.ts
+++ b/src/common/editor.ts
@@ -85,7 +85,7 @@ class Editor {
 		return this.#document.numRows;
 	}
 
-	private get currentRow(): Row | null {
+	private get currentRow(): Option<Row> {
 		return this.#document.row(this.#cursor.y);
 	}
 
@@ -153,8 +153,8 @@ class Editor {
 				break;
 
 			case KeyCommand.End:
-				if (this.currentRow !== null) {
-					this.#cursor.x = this.currentRow.size;
+				if (this.currentRow.isSome()) {
+					this.#cursor.x = this.currentRow.unwrap().size;
 				}
 				break;
 
@@ -360,25 +360,27 @@ class Editor {
 	}
 
 	private moveCursor(char: string): void {
+		const rowSize = (this.currentRow.isSome())
+			? this.currentRow.unwrap().size
+			: 0;
+
 		switch (char) {
 			case KeyCommand.ArrowLeft:
 				if (this.#cursor.x > 0) {
 					this.#cursor.x--;
 				} else if (this.#cursor.y > 0) {
 					this.#cursor.y--;
-					this.#cursor.x = (this.currentRow !== null)
-						? this.currentRow.size
-						: 0;
+					this.#cursor.x = rowSize;
 				}
 				break;
 			case KeyCommand.ArrowRight:
 				if (
-					this.currentRow !== null && this.#cursor.x < this.currentRow.size
+					this.currentRow.isSome() && this.#cursor.x < rowSize
 				) {
 					this.#cursor.x++;
 				} else if (
-					this.currentRow !== null &&
-					this.#cursor.x === this.currentRow.size
+					this.currentRow.isSome() &&
+					this.#cursor.x === rowSize
 				) {
 					this.#cursor.y++;
 					this.#cursor.x = 0;
@@ -396,16 +398,15 @@ class Editor {
 				break;
 		}
 
-		const rowLen = this.currentRow?.size ?? 0;
-		if (this.#cursor.x > rowLen) {
-			this.#cursor.x = rowLen;
+		if (this.#cursor.x > rowSize) {
+			this.#cursor.x = rowSize;
 		}
 	}
 
 	private scroll(): void {
 		this.#renderX = 0;
-		if (this.currentRow !== null) {
-			this.#renderX = this.currentRow.cxToRx(this.#cursor.x);
+		if (this.currentRow.isSome()) {
+			this.#renderX = this.currentRow.unwrap().cxToRx(this.#cursor.x);
 		}
 
 		if (this.#cursor.y < this.#offset.y) {
@@ -475,12 +476,14 @@ class Editor {
 	}
 
 	private drawFileRow(y: number): void {
-		const row = this.#document.row(y);
-		if (row === null) {
+		const maybeRow = this.#document.row(y);
+		if (maybeRow.isNone()) {
 			log(`Trying to draw non-existent row '${y}'`, LogLevel.Warning);
 			return this.drawPlaceholderRow(y);
 		}
 
+		const row = maybeRow.unwrap();
+
 		const len = Math.min(
 			posSub(row.rsize, this.#offset.x),
 			this.#screen.cols,
diff --git a/src/common/search.ts b/src/common/search.ts
index 12ae87a..ee120b1 100644
--- a/src/common/search.ts
+++ b/src/common/search.ts
@@ -64,11 +64,11 @@ export class Search {
 			const current = this.getNextRow(parent.numRows);
 			const row = parent.row(current);
 
-			if (row === null) {
+			if (row.isNone()) {
 				continue;
 			}
 
-			const possible = row.find(q);
+			const possible = row.unwrap().find(q);
 			if (possible.isSome()) {
 				this.lastMatch = current;
 				return possible.map((p: number) => Position.at(p, current));