Preparing for file reading/writing

src/bun/file_io.ts

@@ -0,0 +1,15 @@
+import { IFIO } from '../common/types.ts';
+
+import { readFileSync } from 'node:fs';
+
+const BunFileIO: IFIO = {
+	openFile: async (path: string): Promise<string> => {
+		const file = await Bun.file(path);
+		return await file.text();
+	},
+	openFileSync: (path: string): string => {
+		return readFileSync(path);
+	},
+};
+
+export default BunFileIO;

src/bun/mod.ts

@@ -5,6 +5,7 @@
 import { getTermios, IRuntime, RunTimeType } from '../common/mod.ts';
 import BunFFI from './ffi.ts';
 import BunTerminalIO from './terminal_io.ts';
+import BunFileIO from './file_io.ts';
 
 process.on('error', async (e) => {
 	(await getTermios()).disableRawMode();
@@ -14,8 +15,9 @@ process.on('error', async (e) => {
 
 const BunRuntime: IRuntime = {
 	name: RunTimeType.Bun,
+	file: BunFileIO,
 	ffi: BunFFI,
-	io: BunTerminalIO,
+	term: BunTerminalIO,
 	onExit: (cb: () => void): void => {
 		process.on('beforeExit', cb);
 		process.on('exit', cb);

src/bun/terminal_io.ts

@@ -1,10 +1,11 @@
 /**
  * Wrap the runtime-specific hook into stdin
  */
-import { ITerminalIO, ITerminalSize } from '../common/mod.ts';
-import Ansi from '../common/editor/ansi.ts';
+import { ITerminal, ITerminalSize } from '../common/mod.ts';
+import Ansi from '../common/ansi.ts';
 
-const BunTerminalIO: ITerminalIO = {
+const BunTerminalIO: ITerminal = {
+	argv: Bun.argv,
 	inputLoop: async function* inputLoop() {
 		for await (const chunk of Bun.stdin.stream()) {
 			yield chunk;
@@ -45,7 +46,7 @@ const BunTerminalIO: ITerminalIO = {
 			cols: 80,
 		};
 	},
-	write: async function write(s: string): Promise<void> {
+	writeStdout: async function write(s: string): Promise<void> {
 		const buffer = new TextEncoder().encode(s);
 
 		await Bun.write(Bun.stdout, buffer);

src/common/buffer.ts

@@ -0,0 +1,36 @@
+import { strlen } from './utils.ts';
+import { getRuntime } from './runtime.ts';
+
+class Buffer {
+	#b = '';
+
+	constructor() {
+	}
+
+	public append(s: string): void {
+		this.#b += s;
+	}
+
+	public appendLine(s: string): void {
+		this.#b += s + '\r\n';
+	}
+
+	public clear(): void {
+		this.#b = '';
+	}
+
+	/**
+	 * Output the contents of the buffer into stdout
+	 */
+	public async flush() {
+		const { term } = await getRuntime();
+		await term.writeStdout(this.#b);
+		this.clear();
+	}
+
+	public strlen(): number {
+		return strlen(this.#b);
+	}
+}
+
+export default Buffer;

src/common/document.ts

@@ -1,4 +1,4 @@
-import { chars } from '../utils.ts';
+import { chars } from './utils.ts';
 
 export class Row {
 	chars: string[] = [];
@@ -27,7 +27,7 @@ export class Document {
 		return new Document();
 	}
 
-	public static open(): Document {
+	public static open(_filename: string): Document {
 		const doc = new Document();
 		const line = 'Hello, World!';
 		const row = new Row(line);

src/common/editor.ts

@@ -1,21 +1,23 @@
 import Ansi, { KeyCommand } from './ansi.ts';
 import Buffer from './buffer.ts';
 import Document from './document.ts';
-import { ctrl_key, IPoint, ITerminalSize, truncate, VERSION } from '../mod.ts';
+import { ctrl_key, IPoint, ITerminalSize, truncate, VERSION } from './mod.ts';
 
 export class Editor {
 	#buffer: Buffer;
 	#screen: ITerminalSize;
 	#cursor: IPoint;
 	#document: Document;
-	constructor(terminalSize: ITerminalSize) {
+	constructor(terminalSize: ITerminalSize, args: string[]) {
 		this.#buffer = new Buffer();
 		this.#screen = terminalSize;
 		this.#cursor = {
 			x: 0,
 			y: 0,
 		};
-		this.#document = Document.open();
+		this.#document = (args.length >= 2)
+			? Document.open(args[1])
+			: Document.empty();
 	}
 
 	// --------------------------------------------------------------------------

src/common/editor/buffer.ts

@@ -1,37 +0,0 @@
-import { strlen } from '../utils.ts';
-import { getRuntime } from '../runtime.ts';
-
-class Buffer {
-	#b = '';
-
-	constructor() {
-	}
-
-	append(s: string): void {
-		this.#b += s;
-	}
-
-	appendLine(s: string): void {
-		this.#b += s + '\r\n';
-	}
-
-	clear(): void {
-		this.#b = '';
-	}
-
-	getBuffer(): string {
-		return this.#b;
-	}
-
-	async flush() {
-		const { io } = await getRuntime();
-		await io.write(this.#b);
-		this.clear();
-	}
-
-	strlen(): number {
-		return strlen(this.#b);
-	}
-}
-
-export default Buffer;

src/common/editor/mod.ts

@@ -1 +0,0 @@
-export * from './editor.ts';

src/common/mod.ts

@@ -1,4 +1,4 @@
-export * from './editor/mod.ts';
+export * from './editor.ts';
 export * from './runtime.ts';
 export * from './termios.ts';
 export * from './utils.ts';

src/common/types.ts

@@ -47,9 +47,13 @@ export interface ITerminalSize {
 }
 
 /**
- * Runtime-specific IO streams
+ * Runtime-specific terminal functionality
  */
-export interface ITerminalIO {
+export interface ITerminal {
+	/**
+	 * The arguments passed to the program on launch
+	 */
+	argv: string[];
 	/**
 	 * The generator function returning chunks of input from the stdin stream
 	 */
@@ -63,7 +67,15 @@ export interface ITerminalIO {
 	/**
 	 * Pipe a string to stdout
 	 */
-	write(s: string): Promise<void>;
+	writeStdout(s: string): Promise<void>;
+}
+
+/**
+ * Runtime-specific file handling
+ */
+export interface IFIO {
+	openFile(path: string): Promise<string>;
+	openFileSync(path: string): string;
 }
 
 export interface IRuntime {
@@ -78,7 +90,11 @@ export interface IRuntime {
 	/**
 	 * Runtime-specific terminal functionality
 	 */
-	io: ITerminalIO;
+	term: ITerminal;
+	/**
+	 * Runtime-specific file system io
+	 */
+	file: IFIO;
 
 	/**
 	 * Set a beforeExit/beforeUnload event handler for the runtime

src/deno/file_io.ts

@@ -0,0 +1,16 @@
+import { IFIO } from '../common/types.ts';
+
+const DenoFileIO: IFIO = {
+	openFile: async function (path: string): Promise<string> {
+		const decoder = new TextDecoder('utf-8');
+		const data = await Deno.readFile(path);
+		return decoder.decode(data);
+	},
+	openFileSync: function (path: string): string {
+		const decoder = new TextDecoder('utf-8');
+		const data = Deno.readFileSync(path);
+		return decoder.decode(data);
+	},
+};
+
+export default DenoFileIO;

src/deno/mod.ts

@@ -4,11 +4,13 @@
 import { IRuntime, RunTimeType } from '../common/mod.ts';
 import DenoFFI from './ffi.ts';
 import DenoTerminalIO from './terminal_io.ts';
+import DenoFileIO from './file_io.ts';
 
 const DenoRuntime: IRuntime = {
 	name: RunTimeType.Deno,
+	file: DenoFileIO,
 	ffi: DenoFFI,
-	io: DenoTerminalIO,
+	term: DenoTerminalIO,
 	onExit: (cb: () => void): void => {
 		globalThis.addEventListener('onbeforeunload', cb);
 		globalThis.onbeforeunload = cb;

src/deno/terminal_io.ts

@@ -1,6 +1,7 @@
-import { ITerminalIO, ITerminalSize } from '../common/types.ts';
+import { ITerminal, ITerminalSize } from '../common/types.ts';
 
-const DenoTerminalIO: ITerminalIO = {
+const DenoTerminalIO: ITerminal = {
+	argv: Deno.args,
 	/**
 	 * Wrap the runtime-specific hook into stdin
 	 */
@@ -17,7 +18,7 @@ const DenoTerminalIO: ITerminalIO = {
 			cols: size.columns,
 		});
 	},
-	write: async function write(s: string): Promise<void> {
+	writeStdout: async function write(s: string): Promise<void> {
 		const buffer: Uint8Array = new TextEncoder().encode(s);
 		const stdout: WritableStream<Uint8Array> = Deno.stdout.writable;
 

src/scroll.ts

@@ -2,7 +2,7 @@
  * The starting point for running scroll
  */
 import { Editor, getRuntime, getTermios } from './common/mod.ts';
-import { KeyCommand } from './common/editor/ansi.ts';
+import { KeyCommand } from './common/ansi.ts';
 
 const decoder = new TextDecoder();
 
@@ -35,7 +35,7 @@ function readKey(raw: Uint8Array): string {
 
 export async function main() {
 	const runTime = await getRuntime();
-	const { io, onExit } = runTime;
+	const { term, onExit } = runTime;
 
 	// Setup raw mode, and tear down on error or normal exit
 	const t = await getTermios();
@@ -44,14 +44,14 @@ export async function main() {
 		t.disableRawMode();
 	});
 
-	const terminalSize = await io.getTerminalSize();
+	const terminalSize = await term.getTerminalSize();
 
 	// Create the editor itself
-	const editor = new Editor(terminalSize);
+	const editor = new Editor(terminalSize, term.argv);
 	await editor.refreshScreen();
 
 	// The main event loop
-	for await (const chunk of io.inputLoop()) {
+	for await (const chunk of term.inputLoop()) {
 		// Process input
 		const char = readKey(chunk);
 		const shouldLoop = editor.processKeyPress(char);