output.js

/*jshint node:true */
/*
  The MIT License (MIT)

  Copyright (c) 2007-2018 Einar Lielmanis, Liam Newman, and contributors.

  Permission is hereby granted, free of charge, to any person
  obtaining a copy of this software and associated documentation files
  (the "Software"), to deal in the Software without restriction,
  including without limitation the rights to use, copy, modify, merge,
  publish, distribute, sublicense, and/or sell copies of the Software,
  and to permit persons to whom the Software is furnished to do so,
  subject to the following conditions:

  The above copyright notice and this permission notice shall be
  included in all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  SOFTWARE.
*/

'use strict';

function OutputLine(parent) {
  this.__parent = parent;
  this.__character_count = 0;
  // use indent_count as a marker for this.__lines that have preserved indentation
  this.__indent_count = -1;
  this.__alignment_count = 0;
  this.__wrap_point_index = 0;
  this.__wrap_point_character_count = 0;
  this.__wrap_point_indent_count = -1;
  this.__wrap_point_alignment_count = 0;

  this.__items = [];
}

OutputLine.prototype.clone_empty = function() {
  var line = new OutputLine(this.__parent);
  line.set_indent(this.__indent_count, this.__alignment_count);
  return line;
};

OutputLine.prototype.item = function(index) {
  if (index < 0) {
    return this.__items[this.__items.length + index];
  } else {
    return this.__items[index];
  }
};

OutputLine.prototype.has_match = function(pattern) {
  for (var lastCheckedOutput = this.__items.length - 1; lastCheckedOutput >= 0; lastCheckedOutput--) {
    if (this.__items[lastCheckedOutput].match(pattern)) {
      return true;
    }
  }
  return false;
};

OutputLine.prototype.set_indent = function(indent, alignment) {
  if (this.is_empty()) {
    this.__indent_count = indent || 0;
    this.__alignment_count = alignment || 0;
    this.__character_count = this.__parent.get_indent_size(this.__indent_count, this.__alignment_count);
  }
};

OutputLine.prototype._set_wrap_point = function() {
  if (this.__parent.wrap_line_length) {
    this.__wrap_point_index = this.__items.length;
    this.__wrap_point_character_count = this.__character_count;
    this.__wrap_point_indent_count = this.__parent.next_line.__indent_count;
    this.__wrap_point_alignment_count = this.__parent.next_line.__alignment_count;
  }
};

OutputLine.prototype._should_wrap = function() {
  return this.__wrap_point_index &&
    this.__character_count > this.__parent.wrap_line_length &&
    this.__wrap_point_character_count > this.__parent.next_line.__character_count;
};

OutputLine.prototype._allow_wrap = function() {
  if (this._should_wrap()) {
    this.__parent.add_new_line();
    var next = this.__parent.current_line;
    next.set_indent(this.__wrap_point_indent_count, this.__wrap_point_alignment_count);
    next.__items = this.__items.slice(this.__wrap_point_index);
    this.__items = this.__items.slice(0, this.__wrap_point_index);

    next.__character_count += this.__character_count - this.__wrap_point_character_count;
    this.__character_count = this.__wrap_point_character_count;

    if (next.__items[0] === " ") {
      next.__items.splice(0, 1);
      next.__character_count -= 1;
    }
    return true;
  }
  return false;
};

OutputLine.prototype.is_empty = function() {
  return this.__items.length === 0;
};

OutputLine.prototype.last = function() {
  if (!this.is_empty()) {
    return this.__items[this.__items.length - 1];
  } else {
    return null;
  }
};

OutputLine.prototype.push = function(item) {
  this.__items.push(item);
  var last_newline_index = item.lastIndexOf('\n');
  if (last_newline_index !== -1) {
    this.__character_count = item.length - last_newline_index;
  } else {
    this.__character_count += item.length;
  }
};

OutputLine.prototype.pop = function() {
  var item = null;
  if (!this.is_empty()) {
    item = this.__items.pop();
    this.__character_count -= item.length;
  }
  return item;
};


OutputLine.prototype._remove_indent = function() {
  if (this.__indent_count > 0) {
    this.__indent_count -= 1;
    this.__character_count -= this.__parent.indent_size;
  }
};

OutputLine.prototype._remove_wrap_indent = function() {
  if (this.__wrap_point_indent_count > 0) {
    this.__wrap_point_indent_count -= 1;
  }
};
OutputLine.prototype.trim = function() {
  while (this.last() === ' ') {
    this.__items.pop();
    this.__character_count -= 1;
  }
};

OutputLine.prototype.toString = function() {
  var result = '';
  if (this.is_empty()) {
    if (this.__parent.indent_empty_lines) {
      result = this.__parent.get_indent_string(this.__indent_count);
    }
  } else {
    result = this.__parent.get_indent_string(this.__indent_count, this.__alignment_count);
    result += this.__items.join('');
  }
  return result;
};

function IndentStringCache(options, baseIndentString) {
  this.__cache = [''];
  this.__indent_size = options.indent_size;
  this.__indent_string = options.indent_char;
  if (!options.indent_with_tabs) {
    this.__indent_string = new Array(options.indent_size + 1).join(options.indent_char);
  }

  // Set to null to continue support for auto detection of base indent
  baseIndentString = baseIndentString || '';
  if (options.indent_level > 0) {
    baseIndentString = new Array(options.indent_level + 1).join(this.__indent_string);
  }

  this.__base_string = baseIndentString;
  this.__base_string_length = baseIndentString.length;
}

IndentStringCache.prototype.get_indent_size = function(indent, column) {
  var result = this.__base_string_length;
  column = column || 0;
  if (indent < 0) {
    result = 0;
  }
  result += indent * this.__indent_size;
  result += column;
  return result;
};

IndentStringCache.prototype.get_indent_string = function(indent_level, column) {
  var result = this.__base_string;
  column = column || 0;
  if (indent_level < 0) {
    indent_level = 0;
    result = '';
  }
  column += indent_level * this.__indent_size;
  this.__ensure_cache(column);
  result += this.__cache[column];
  return result;
};

IndentStringCache.prototype.__ensure_cache = function(column) {
  while (column >= this.__cache.length) {
    this.__add_column();
  }
};

IndentStringCache.prototype.__add_column = function() {
  var column = this.__cache.length;
  var indent = 0;
  var result = '';
  if (this.__indent_size && column >= this.__indent_size) {
    indent = Math.floor(column / this.__indent_size);
    column -= indent * this.__indent_size;
    result = new Array(indent + 1).join(this.__indent_string);
  }
  if (column) {
    result += new Array(column + 1).join(' ');
  }

  this.__cache.push(result);
};

function Output(options, baseIndentString) {
  this.__indent_cache = new IndentStringCache(options, baseIndentString);
  this.raw = false;
  this._end_with_newline = options.end_with_newline;
  this.indent_size = options.indent_size;
  this.wrap_line_length = options.wrap_line_length;
  this.indent_empty_lines = options.indent_empty_lines;
  this.__lines = [];
  this.previous_line = null;
  this.current_line = null;
  this.next_line = new OutputLine(this);
  this.space_before_token = false;
  this.non_breaking_space = false;
  this.previous_token_wrapped = false;
  // initialize
  this.__add_outputline();
}

Output.prototype.__add_outputline = function() {
  this.previous_line = this.current_line;
  this.current_line = this.next_line.clone_empty();
  this.__lines.push(this.current_line);
};

Output.prototype.get_line_number = function() {
  return this.__lines.length;
};

Output.prototype.get_indent_string = function(indent, column) {
  return this.__indent_cache.get_indent_string(indent, column);
};

Output.prototype.get_indent_size = function(indent, column) {
  return this.__indent_cache.get_indent_size(indent, column);
};

Output.prototype.is_empty = function() {
  return !this.previous_line && this.current_line.is_empty();
};

Output.prototype.add_new_line = function(force_newline) {
  // never newline at the start of file
  // otherwise, newline only if we didn't just add one or we're forced
  if (this.is_empty() ||
    (!force_newline && this.just_added_newline())) {
    return false;
  }

  // if raw output is enabled, don't print additional newlines,
  // but still return True as though you had
  if (!this.raw) {
    this.__add_outputline();
  }
  return true;
};

Output.prototype.get_code = function(eol) {
  this.trim(true);

  // handle some edge cases where the last tokens
  // has text that ends with newline(s)
  var last_item = this.current_line.pop();
  if (last_item) {
    if (last_item[last_item.length - 1] === '\n') {
      last_item = last_item.replace(/\n+$/g, '');
    }
    this.current_line.push(last_item);
  }

  if (this._end_with_newline) {
    this.__add_outputline();
  }

  var sweet_code = this.__lines.join('\n');

  if (eol !== '\n') {
    sweet_code = sweet_code.replace(/[\n]/g, eol);
  }
  return sweet_code;
};

Output.prototype.set_wrap_point = function() {
  this.current_line._set_wrap_point();
};

Output.prototype.set_indent = function(indent, alignment) {
  indent = indent || 0;
  alignment = alignment || 0;

  // Next line stores alignment values
  this.next_line.set_indent(indent, alignment);

  // Never indent your first output indent at the start of the file
  if (this.__lines.length > 1) {
    this.current_line.set_indent(indent, alignment);
    return true;
  }

  this.current_line.set_indent();
  return false;
};

Output.prototype.add_raw_token = function(token) {
  for (var x = 0; x < token.newlines; x++) {
    this.__add_outputline();
  }
  this.current_line.set_indent(-1);
  this.current_line.push(token.whitespace_before);
  this.current_line.push(token.text);
  this.space_before_token = false;
  this.non_breaking_space = false;
  this.previous_token_wrapped = false;
};

Output.prototype.add_token = function(printable_token) {
  this.__add_space_before_token();
  this.current_line.push(printable_token);
  this.space_before_token = false;
  this.non_breaking_space = false;
  this.previous_token_wrapped = this.current_line._allow_wrap();
};

Output.prototype.__add_space_before_token = function() {
  if (this.space_before_token && !this.just_added_newline()) {
    if (!this.non_breaking_space) {
      this.set_wrap_point();
    }
    this.current_line.push(' ');
  }
};

Output.prototype.remove_indent = function(index) {
  var output_length = this.__lines.length;
  while (index < output_length) {
    this.__lines[index]._remove_indent();
    index++;
  }
  this.current_line._remove_wrap_indent();
};

Output.prototype.trim = function(eat_newlines) {
  eat_newlines = (eat_newlines === undefined) ? false : eat_newlines;

  this.current_line.trim();

  while (eat_newlines && this.__lines.length > 1 &&
    this.current_line.is_empty()) {
    this.__lines.pop();
    this.current_line = this.__lines[this.__lines.length - 1];
    this.current_line.trim();
  }

  this.previous_line = this.__lines.length > 1 ?
    this.__lines[this.__lines.length - 2] : null;
};

Output.prototype.just_added_newline = function() {
  return this.current_line.is_empty();
};

Output.prototype.just_added_blankline = function() {
  return this.is_empty() ||
    (this.current_line.is_empty() && this.previous_line.is_empty());
};

Output.prototype.ensure_empty_line_above = function(starts_with, ends_with) {
  var index = this.__lines.length - 2;
  while (index >= 0) {
    var potentialEmptyLine = this.__lines[index];
    if (potentialEmptyLine.is_empty()) {
      break;
    } else if (potentialEmptyLine.item(0).indexOf(starts_with) !== 0 &&
      potentialEmptyLine.item(-1) !== ends_with) {
      this.__lines.splice(index + 1, 0, new OutputLine(this));
      this.previous_line = this.__lines[this.__lines.length - 2];
      break;
    }
    index--;
  }
};

module.exports.Output = Output;