monaco-editor-core/esm/vs/editor/common/core/positionToOffset.js

A browser based code editor

import { OffsetRange } from './offsetRange.js';
import { TextLength } from './textLength.js';
export class PositionOffsetTransformer {
    constructor(text) {
        this.text = text;
        this.lineStartOffsetByLineIdx = [];
        this.lineStartOffsetByLineIdx.push(0);
        for (let i = 0; i < text.length; i++) {
            if (text.charAt(i) === '\n') {
                this.lineStartOffsetByLineIdx.push(i + 1);
            }
        }
    }
    getOffset(position) {
        return this.lineStartOffsetByLineIdx[position.lineNumber - 1] + position.column - 1;
    }
    getOffsetRange(range) {
        return new OffsetRange(this.getOffset(range.getStartPosition()), this.getOffset(range.getEndPosition()));
    }
    get textLength() {
        const lineIdx = this.lineStartOffsetByLineIdx.length - 1;
        return new TextLength(lineIdx, this.text.length - this.lineStartOffsetByLineIdx[lineIdx]);
    }
}