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| 'use strict';
|
| var ESCAPES = [
| '\u001b',
| '\u009b'
| ];
|
| var END_CODE = 39;
|
| var ESCAPE_CODES = {
| 0: 0,
| 1: 22,
| 2: 22,
| 3: 23,
| 4: 24,
| 7: 27,
| 8: 28,
| 9: 29,
| 30: 39,
| 31: 39,
| 32: 39,
| 33: 39,
| 34: 39,
| 35: 39,
| 36: 39,
| 37: 39,
| 90: 39,
| 40: 49,
| 41: 49,
| 42: 49,
| 43: 49,
| 44: 49,
| 45: 49,
| 46: 49,
| 47: 49
| };
|
| function wrapAnsi(code) {
| return ESCAPES[0] + '[' + code + 'm';
| }
|
| module.exports = function (str, begin, end) {
| end = end || str.length;
| var insideEscape = false;
| var escapeCode;
| var visible = 0;
| var output = '';
|
| for (var i = 0; i < str.length; i++) {
| var leftEscape = false;
| var x = str[i];
|
| if (ESCAPES.indexOf(x) !== -1) {
| insideEscape = true;
| var code = /[0-9][^m]*/.exec(str.slice(i, i + 4));
| escapeCode = code === END_CODE ? null : code;
| } else if (insideEscape && x === 'm') {
| insideEscape = false;
| leftEscape = true;
| }
|
| if (!insideEscape && !leftEscape) {
| ++visible;
| }
|
| if (visible > begin && visible <= end) {
| output += x;
| } else if (visible === begin && escapeCode !== undefined && escapeCode !== END_CODE) {
| output += wrapAnsi(escapeCode);
| } else if (visible >= end) {
| if (escapeCode !== undefined) {
| output += wrapAnsi(ESCAPE_CODES[escapeCode] || END_CODE);
| }
| break;
| }
| }
|
| return output;
| };
|
|
