almost a real repl

repl.ts

@@ -1,11 +1,22 @@
 import faux from "./builtins.ts";
 import { getKeysPressed, shiftKeyDown, shiftMap, K } from "./keyboard.ts";
 import { font } from "./font.ts";
+import { runCode } from "./runcode.ts";
 
+const lineHeight = 6;
+
+let maxLineLen = 0;
 let line = "";
 let index = 0;
+let y = 0;
+let result = "";
 
 const update = () => {
+	if (result) {
+		console.log("result:", result);
+		y += lineHeight; // TODO: multiply if multiline
+		result = "";
+	}
 	for (const key of getKeysPressed()) {
 		let char = String.fromCharCode(key).toLowerCase();
 		if (shiftKeyDown()) {
@@ -19,10 +30,9 @@ const update = () => {
 			line = line.slice(0, index)+char+line.slice(index);
 			index += 1;
 		} else if (key === K.BACKSPACE) {
-			line = line.slice(0, -1);
-			index -= 1;
-			if (index < 0) {
-				index = 0;
+			if (index > 0) {
+				line = line.slice(0, index-1)+line.slice(index);
+				index -= 1;
 			}
 		} else if (key === K.ARROW_LEFT) {
 			index -= 1;
@@ -34,14 +44,28 @@ const update = () => {
 			if (index > line.length) {
 				index = line.length;
 			}
+		} else if (key === K.ENTER) {
+			const ran = runCode('return '+line);
+			console.log('ran:', ran);
+			result = ran?.toString?.();
+			maxLineLen = 0;
+			line = "";
+			index = 0;
+			y += lineHeight;
 		}
 	}
+	maxLineLen = Math.max(maxLineLen, line.length);
 }
 
 const draw = () => {
-	faux.clear_screen();
-	faux.draw_rect((2+index)*4, 0, 5, 6, 3);
-	faux.draw_text(0, 0, "> "+line);
+	if (result) {
+		faux.draw_rect(0, y, 4*result.length+1, lineHeight+1, 6);
+		faux.draw_text(0, y, result);
+	} else {
+		faux.draw_rect(0, y, 4*(2+maxLineLen+1)+1, lineHeight+1, 6);
+		faux.draw_rect((2+index)*4, y+1, 4, lineHeight-1, 3);
+		faux.draw_text(0, y, "> "+line);
+	}
 }
 
 export const repl = {