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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;
};
|
