Initial commit: LWP (Line Wrapping Program) with deno compile and formatting

Added support for deno compilation and formatting to .deno.json file.
Implemented basic line wrapping functionality in src/lwrap.ts, using Wrapper
class to wrap lines at 80 characters.

src/lwrap.ts

@@ -0,0 +1,75 @@
+#!/usr/bin/env -S deno run
+
+async function main() {
+	const input = readable_text(Deno.stdin.readable)
+	const output = writable_text(Deno.stdout.writable).getWriter()
+	const wrapper = new Wrapper(80)
+	for await (const chunk of input) {
+		const wrapped = wrapper.wrap(chunk)
+		for (const chunk of wrapped) await output.write(chunk)
+	}
+}
+
+function readable_text(readable: ReadableStream<Uint8Array<ArrayBuffer>>): ReadableStream<string> {
+	const decoder = new TextDecoderStream()
+	readable.pipeTo(decoder.writable)
+	return decoder.readable
+}
+
+function writable_text(writable: WritableStream<Uint8Array<ArrayBufferLike>>): WritableStream<string> {
+	const decoder = new TextEncoderStream()
+	decoder.readable.pipeTo(writable)
+	return decoder.writable
+}
+
+class Wrapper {
+	current_length = 0
+	prev_sep = ""
+
+	public constructor(
+		private max_width: number,
+	) {}
+
+	*wrap(chunk: string) {
+		let is_first = true
+		for (const line of chunk.split("\n")) {
+			this.current_length = 0
+			if (is_first) is_first = false
+			else yield "\n"
+			for (const word of this.split(line)) {
+				const length_after = this.current_length + word.word.length + this.prev_sep.length
+				if (length_after > 80) {
+					yield "\n"
+					yield word.word
+					this.prev_sep = word.sep
+					this.current_length = word.word.length
+				} else {
+					yield this.prev_sep
+					yield word.word
+					this.prev_sep = word.sep
+					this.current_length = length_after
+				}
+			}
+		}
+	}
+
+	*split(chunk: string) {
+		const separators = [" "]
+		let word_start = 0
+		let index = 0
+		for (const char of chunk) {
+			if (separators.includes(char)) {
+				const word = chunk.substring(word_start, index)
+				const sep = char
+				yield { word, sep }
+				word_start = index + 1
+			}
+			index += 1
+		}
+		const word = chunk.substring(word_start, index)
+		const sep = ""
+		if (word_start != index) yield { word, sep }
+	}
+}
+
+if (import.meta.main) await main()