Rename i18n to intl

pkg/i18n/number_format.dart

-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-#library("number_format");
-
-#import("intl.dart");
-#import("number_symbols.dart");
-#import("number_symbols_data.dart");
-
-class NumberFormat {
-  /** Variables to determine how number printing behaves. */
-  // TODO(alanknight): If these remain as variables and are set based on the
-  // pattern, can we make them final?
-  String _negativePrefix = '-';
-  String _positivePrefix = '';
-  String _negativeSuffix = '';
-  String _positiveSuffix = '';
-  /** How many numbers in a group when using punctuation to group digits in
-   * large numbers. e.g. in en_US: "1,000,000" has a grouping size of 3 digits
-   * between commas.
-   */
-  int _groupingSize = 3;
-  bool _decimalSeparatorAlwaysShown = false;
-  bool _useExponentialNotation = false;
-  int _maximumIntegerDigits = 40;
-  int _minimumIntegerDigits = 1;
-  int _maximumFractionDigits = 3; // invariant, >= minFractionDigits
-  int _minimumFractionDigits = 0;
-  int _minimumExponentDigits = 0;
-  bool _useSignForPositiveExponent = false;
-
-  /** The locale in which we print numbers. */
-  final String _locale;
-
-  /** Caches the symbols used for our locale. */
-  NumberSymbols _symbols;
-
-  /**
-   * Transient internal state in which to build up the result of the format
-   * operation. We can have this be just an instance variable because Dart is
-   * single-threaded and unless we do an asynchronous operation in the process
-   * of formatting then there will only ever be one number being formatted
-   * at a time. In languages with threads we'd need to pass this on the stack.
-   */
-  StringBuffer _buffer;
-
-  /**
-   * Create a number format that prints in [newPattern] as it applies in
-   * [locale].
-   */
-  NumberFormat([String newPattern, String locale]):
-    _locale = Intl.verifiedLocale(locale) {
-    // TODO(alanknight): There will need to be some kind of async setup
-    // operations so as not to bring along every locale in every program.
-    _symbols = numberFormatSymbols[_locale];
-    _setPattern(newPattern);
-  }
-
-  /**
-   * Return the locale code in which we operate, e.g. 'en_US' or 'pt'.
-   */
-  String get locale() => _locale;
-
-  /**
-   * Return the symbols which are used in our locale. Cache them to avoid
-   * repeated lookup.
-   */
-  NumberSymbols get symbols() {
-    return _symbols;
-  }
-
-  // TODO(alanknight): Actually use the pattern and locale.
-  _setPattern(String x) {}
-
-  /**
-   * Format [number] according to our pattern and return the formatted string.
-   */
-  String format(num number) {
-    // TODO(alanknight): Do we have to do anything for printing numbers bidi?
-    // Or are they always printed left to right?
-    if (number.isNaN()) return symbols.NAN;
-    if (number.isInfinite()) return "${_signPrefix(number)}${symbols.INFINITY}";
-
-    _newBuffer();
-    _add(_signPrefix(number));
-    _formatNumber(number.abs());
-    _add(_signSuffix(number));
-
-    var result = _buffer.toString();
-    _buffer = null;
-    return result;
-  }
-
-  /**
-   * Format the main part of the number in the form dictated by the pattern.
-   */
-  void _formatNumber(num number) {
-    if (_useExponentialNotation) {
-      _formatExponential(number);
-    } else {
-      _formatFixed(number);
-    }
-  }
-
-  /** Format the number in exponential notation. */
-  _formatExponential(num number) {
-    if (number == 0.0) {
-      _formatFixed(number);
-      _formatExponent(0);
-      return;
-    }
-
-    var exponent = (Math.log(number) / Math.log(10)).floor();
-    var mantissa = number / Math.pow(10, exponent);
-
-    if (_minimumIntegerDigits < 1) {
-      exponent++;
-      mantissa /= 10;
-    } else {
-      exponent -= _minimumIntegerDigits - 1;
-      mantissa *= Math.pow(10, _minimumIntegerDigits - 1);
-    }
-    _formatFixed(number);
-    _formatExponent(exponent);
-  }
-
-  /**
-   * Format the exponent portion, e.g. in "1.3e-5" the "e-5".
-   */
-  void _formatExponent(num exponent) {
-    _add(symbols.EXP_SYMBOL);
-    if (exponent < 0) {
-      exponent = -exponent;
-      _add(symbols.MINUS_SIGN);
-    } else if (_useSignForPositiveExponent) {
-      _add(symbols.PLUS_SIGN);
-    }
-    _pad(_minimumExponentDigits, exponent.toString());
-  }
-
-  /**
-   * Format the basic number portion, inluding the fractional digits.
-   */
-  void _formatFixed(num number) {
-    // Round the number.
-    var power = Math.pow(10, _maximumFractionDigits);
-    var intValue = number.truncate().toInt();
-    var multiplied = (number * power).round();
-    var fracValue = (multiplied - intValue * power).floor().toInt();
-    var fractionPresent = _minimumFractionDigits > 0 || fracValue > 0;
-
-    // On dartj2s the integer part may be large enough to be a floating
-    // point value, in which case we reduce it until it is small enough
-    // to be printed as an integer and pad the remainder with zeros.
-    var paddingDigits = new StringBuffer();
-    while (intValue is! int) {
-      paddingDigits.add(symbols.ZERO_DIGIT);
-      intValue = (intValue / 10).toInt();
-    }
-    var integerDigits = "${intValue}${paddingDigits}".charCodes();
-    var digitLength = integerDigits.length;
-
-    if (_hasPrintableIntegerPart(intValue)) {
-      _pad(_minimumIntegerDigits - digitLength);
-      for (var i = 0; i < digitLength; i++) {
-        _addDigit(integerDigits[i]);
-        _group(digitLength, i);
-      }
-    } else if (!fractionPresent) {
-      // If neither fraction nor integer part exists, just print zero.
-      _addZero();
-    }
-
-    _decimalSeparator(fractionPresent);
-    _formatFractionPart((fracValue + power).toString());
-  }
-
-  /**
-   * Format the part after the decimal place in a fixed point number.
-   */
-  void _formatFractionPart(String fractionPart) {
-    var fractionCodes = fractionPart.charCodes();
-    var fractionLength = fractionPart.length;
-    while (fractionPart[fractionLength - 1] == '0' &&
-           fractionLength > _minimumFractionDigits + 1) {
-      fractionLength--;
-    }
-    for (var i = 1; i < fractionLength; i++) {
-      _addDigit(fractionCodes[i]);
-    }
-  }
-
-  /** Print the decimal separator if appropriate. */
-  void _decimalSeparator(bool fractionPresent) {
-    if (_decimalSeparatorAlwaysShown || fractionPresent) {
-      _add(symbols.DECIMAL_SEP);
-    }
-  }
-
-  /**
-   * Return true if we have a main integer part which is printable, either
-   * because we have digits left of the decimal point, or because there are
-   * a minimum number of printable digits greater than 1.
-   */
-  bool _hasPrintableIntegerPart(int intValue) {
-    return intValue > 0 || _minimumIntegerDigits > 0;
-  }
-
-  /**
-   * Create a new empty buffer. See comment on [_buffer] variable for why
-   * we have it as an instance variable rather than passing it on the stack.
-   */
-  void _newBuffer() { _buffer = new StringBuffer(); }
-
-  /** A group of methods that provide support for writing digits and other
-   * required characters into [_buffer] easily.
-   */
-  void _add(String x) { _buffer.add(x);}
-  void _addCharCode(int x) { _buffer.addCharCode(x); }
-  void _addZero() { _buffer.add(symbols.ZERO_DIGIT); }
-  void _addDigit(int x) { _buffer.addCharCode(_localeZero + x - _zero); }
-
-  /** Print padding up to [numberOfDigits] above what's included in [basic]. */
-  void _pad(int numberOfDigits, [String basic = '']) {
-    for (var i = 0; i < numberOfDigits - basic.length; i++) {
-      _add(symbols.ZERO_DIGIT);
-    }
-    for (var x in basic.charCodes()) {
-      _addDigit(x);
-    }
-  }
-
-  /**
-   * We are printing the digits of the number from left to right. We may need
-   * to print a thousands separator or other grouping character as appropriate
-   * to the locale. So we find how many places we are from the end of the number
-   * by subtracting our current [position] from the [totalLength] and print
-   * the separator character every [_groupingSize] digits.
-   */
-  void _group(int totalLength, int position) {
-    var distanceFromEnd = totalLength - position;
-    if (distanceFromEnd <= 1 || _groupingSize <= 0) return;
-    if (distanceFromEnd % _groupingSize == 1) {
-      _add(symbols.GROUP_SEP);
-    }
-  }
-
-  /** Returns the code point for the character '0'. */
-  int get _zero() => '0'.charCodes()[0];
-
-  /** Returns the code point for the locale's zero digit. */
-  int get _localeZero() => symbols.ZERO_DIGIT.charCodeAt(0);
-
-  /**
-   * Returns the prefix for [x] based on whether it's positive or negative.
-   * In en_US this would be '' and '-' respectively.
-   */
-  String _signPrefix(num x) {
-    return x.isNegative() ? _negativePrefix : _positivePrefix;
-  }
-
-  /**
-   * Returns the suffix for [x] based on wether it's positive or negative.
-   * In en_US there are no suffixes for positive or negative.
-   */
-  String _signSuffix(num x) {
-    return x.isNegative() ? _negativeSuffix : _positiveSuffix;
-  }
-}