mark.js

'use strict';


var common = require('./common');


function Mark(name, buffer, position, line, column) {
  this.name     = name;
  this.buffer   = buffer;
  this.position = position;
  this.line     = line;
  this.column   = column;
}


Mark.prototype.getSnippet = function getSnippet(indent, maxLength) {
  var head, start, tail, end, snippet;

  if (!this.buffer) {
    return null;
  }

  indent = indent || 4;
  maxLength = maxLength || 75;

  head = '';
  start = this.position;

  while (start > 0 && -1 === '\x00\r\n\x85\u2028\u2029'.indexOf(this.buffer.charAt(start - 1))) {
    start -= 1;
    if (this.position - start > (maxLength / 2 - 1)) {
      head = ' ... ';
      start += 5;
      break;
    }
  }

  tail = '';
  end = this.position;

  while (end < this.buffer.length && -1 === '\x00\r\n\x85\u2028\u2029'.indexOf(this.buffer.charAt(end))) {
    end += 1;
    if (end - this.position > (maxLength / 2 - 1)) {
      tail = ' ... ';
      end -= 5;
      break;
    }
  }

  snippet = this.buffer.slice(start, end);

  return common.repeat(' ', indent) + head + snippet + tail + '\n' +
         common.repeat(' ', indent + this.position - start + head.length) + '^';
};


Mark.prototype.toString = function toString(compact) {
  var snippet, where = '';

  if (this.name) {
    where += 'in "' + this.name + '" ';
  }

  where += 'at line ' + (this.line + 1) + ', column ' + (this.column + 1);

  if (!compact) {
    snippet = this.getSnippet();

    if (snippet) {
      where += ':\n' + snippet;
    }
  }

  return where;
};


module.exports = Mark;