eslint-plugin-svelte
Version:
ESLint plugin for Svelte using AST
54 lines (53 loc) • 1.61 kB
JavaScript
export class LinesAndColumns {
constructor(code) {
const len = code.length;
const lineStartIndices = [0];
for (let index = 0; index < len; index++) {
const c = code[index];
if (c === '\r') {
const next = code[index + 1] || '';
if (next === '\n') {
index++;
}
lineStartIndices.push(index + 1);
}
else if (c === '\n') {
lineStartIndices.push(index + 1);
}
}
this.lineStartIndices = lineStartIndices;
}
getLocFromIndex(index) {
const lineNumber = sortedLastIndex(this.lineStartIndices, index);
return {
line: lineNumber,
column: index - this.lineStartIndices[lineNumber - 1]
};
}
getIndexFromLoc(loc) {
const lineStartIndex = this.lineStartIndices[loc.line - 1];
const positionIndex = lineStartIndex + loc.column;
return positionIndex;
}
}
/**
* Uses a binary search to determine the highest index at which value should be inserted into array in order to maintain its sort order.
*/
function sortedLastIndex(array, value) {
let lower = 0;
let upper = array.length;
while (lower < upper) {
const mid = Math.floor(lower + (upper - lower) / 2);
const target = array[mid];
if (target < value) {
lower = mid + 1;
}
else if (target > value) {
upper = mid;
}
else {
return mid + 1;
}
}
return upper;
}