byte2line() and line2byte()

Author: J-Fields

src/vimscript/expression/evaluate.ts

@@ -880,6 +880,15 @@ export class EvaluationContext {
         }
         return assertFailed(msg ? toString(msg) : `Expected True but got ${displayValue(actual!)}`);
       }
+      case 'byte2line': {
+        const [_byte] = getArgs(1);
+        const byte = toInt(_byte!);
+        if (byte <= 0) {
+          return int(-1);
+        }
+        return int(this.vimState!.document.positionAt(byte - 1).line + 1);
+      }
+      // TODO: byteidx[comp]
       case 'call': {
         const [_func, arglist, dict] = getArgs(2, 3);
         if (arglist!.type !== 'list') {
@@ -1292,6 +1301,14 @@ export class EvaluationContext {
         const [s, winid] = getArgs(1, 2);
         return int(getpos(toString(s!)).lnum);
       }
+      case 'line2byte': {
+        const [_line] = getArgs(1);
+        const line = toInt(_line!);
+        if (line <= 0) {
+          return int(-1);
+        }
+        return int(this.vimState!.document.offsetAt(new Position(line - 1, 0)) + 1);
+      }
       case 'localtime': {
         return int(Date.now() / 1000);
       }

test/vimscript/expression.test.ts

@@ -594,6 +594,8 @@ suite('Vimscript expressions', () => {
       exprTest('add(0zABCD, 0xEF)', { display: '0zABCDEF' });
     });
 
+    // TODO: byte2line()/line2byte()
+
     suite('call', () => {
       exprTest('call("abs", [-1])', { value: float(1) });
       exprTest('call(function("abs"), [-1])', { value: float(1) });