Begin re-write in proper functional style

src/lib/painter/canvas.ts

@@ -1,47 +1,63 @@
-import { tryCatch } from '@maxmorozoff/try-catch-tuple';
+import { type CursorPos } from 'node:readline'
-import type { CursorPosition } from '../util/terminal';
 
-const setInitialEnd = (pos: {
+// Cursor stuffs
-  origin: CursorPosition;
+interface CursorPosX {
-  end?: CursorPosition;
+  readonly _tag: 'X'
-  lines?: number;
+  readonly value: number
-}) => {
+}
-  if (!pos.end || !pos.lines)
-    throw TypeError("One of 'end' or 'lines' must be set");
-  if (Object.keys(pos).includes('end') || Object.keys(pos).includes('end'))
-    throw TypeError("Cannot set both 'end' and 'lines'");
-  if (pos.end) return pos.end;
-  return {
-    row: pos.origin.row + pos.lines,
-    col: pos.origin.col,
-  };
-};
 
-export const createCanvas = (
+interface CursorPosY {
-  pos: { origin: CursorPosition; end?: CursorPosition; lines?: number },
+  readonly _tag: 'Y'
-  paint: () => Promise<number>,
+  readonly value: number
-  cleanup?: () => Promise<number>
+}
-) => {
-  let currentOrigin = pos.origin;
 
-  let currentEnd;
+const cursorPosX = (x: number): CursorPosX => ({_tag: 'X', value: x})
-  const [endVal, endError] = tryCatch(() => setInitialEnd(pos));
-  if (endError) throw endError;
-  currentEnd = endVal;
 
-  paint();
+const cursorPosY = (x: number): CursorPosY => ({_tag: 'Y', value: x})
-  //
+
-  // Paint function
+type IsCursorPos =
-  //
+  (x: 'X' | 'Y') => (y: CursorPosX | CursorPosY) => boolean
-  // Restore origin position
+const isCursorPos: IsCursorPos = x => y => y._tag === x
-  // Clear to cursor end position
+
-  //
+// Tagged types
-  // API
+interface CanvasOrigin {
-  // ---
+  readonly _tag: 'Origin'
-  // get origin
+  readonly value: CursorPos
-  // get end
+}
-  // move end
+
-  // get line count
+interface CanvasEnd {
-  // clear canvas
+  readonly _tag: 'End'
-  return [1];
+  readonly value: CursorPos
-};
+}
+
+// Canvas type using tagged positions
+type Canvas = {
+  origin: CanvasOrigin,
+  end: CanvasEnd,
+}
+
+// Cursor Position
+// const cursorPos: CursorPos = ()
+
+// Constructor helpers
+const origin = (pos: CursorPos): CanvasOrigin => ({
+  _tag: 'Origin',
+  value: pos,
+})
+
+const end = (pos: CursorPos): CanvasEnd => ({
+  _tag: 'End',
+  value: pos,
+})
+
+// Curried canvas creator with type safety
+const canvas =
+  (origin: CanvasOrigin) => (end: CanvasEnd): Canvas => ({
+    origin,
+    end,
+  })
+
+// Usage with proper type safety
+const myCanvas = canvas(origin({rows: 3, cols: 1}))(
+  end({rows: 8, cols: 1}),
+)