Roll Observatory packages and add a roll script

charted/lib/locale/format/number_format.dart

-/*
- * Copyright 2014 Google Inc. All rights reserved.
- *
- * Use of this source code is governed by a BSD-style
- * license that can be found in the LICENSE file or at
- * https://developers.google.com/open-source/licenses/bsd
- */
-part of charted.locale.format;
-
-/**
- * The number formatter of a given locale.  Applying the locale specific
- * number format, number grouping and currency symbol, etc..  The format
- * function in the NumberFormat class is used to format a number by the given
- * specifier with the number properties of the locale.
- */
-class NumberFormat {
-
-  // [[fill]align][sign][symbol][0][width][,][.precision][type]
-  static RegExp FORMAT_REGEX =
-      new RegExp(r'(?:([^{])?([<>=^]))?([+\- ])?([$#])?(0)?(\d+)?(,)?'
-      r'(\.-?\d+)?([a-z%])?', caseSensitive: false);
-
-  String localeDecimal;
-  String localeThousands;
-  List localeGrouping;
-  List localeCurrency;
-  Function formatGroup;
-
-  NumberFormat(Locale locale) {
-    localeDecimal = locale.decimal;
-    localeThousands = locale.thousands;
-    localeGrouping = locale.grouping;
-    localeCurrency = locale.currency;
-    formatGroup = (localeGrouping != null) ? (value) {
-      var i = value.length,
-          t = [],
-          j = 0,
-          g = localeGrouping[0];
-      while (i > 0 && g > 0) {
-        if (i - g >= 0) {
-          i = i - g;
-        } else {
-          g = i;
-          i = 0;
-        }
-        var length = (i + g) < value.length ? (i + g) : value.length;
-        t.add(value.substring(i, length));
-        g = localeGrouping[j = (j + 1) % localeGrouping.length];
-      }
-      return t.reversed.join(localeThousands);
-    } : (x) => x;
-  }
-
-  /**
-   * Returns a new format function with the given string specifier. A format
-   * function takes a number as the only argument, and returns a string
-   * representing the formatted number. The format specifier is modeled after
-   * Python 3.1's built-in format specification mini-language. The general form
-   * of a specifier is:
-   * [​[fill]align][sign][symbol][0][width][,][.precision][type].
-   *
-   * @see <a href="http://docs.python.org/release/3.1.3/library/string.html#formatspec">format specification mini-language</a>
-   */
-  FormatFunction format(String specifier) {
-    Match match = FORMAT_REGEX.firstMatch(specifier);
-    var fill = match.group(1) != null ? match.group(1) : ' ',
-        align = match.group(2) != null ? match.group(2) : '>',
-        sign = match.group(3) != null ? match.group(3) : '',
-        symbol = match.group(4) != null ? match.group(4) : '',
-        zfill = match.group(5),
-        width = match.group(6) != null ? int.parse(match.group(6)) : 0,
-        comma = match.group(7) != null,
-        precision = match.group(8) != null ?
-            int.parse(match.group(8).substring(1)) : null,
-        type = match.group(9),
-        scale = 1,
-        prefix = '',
-        suffix = '',
-        integer = false;
-
-    if (zfill != null || fill == '0' && align == '=') {
-      zfill = fill = '0';
-      align = '=';
-      if (comma) {
-        width -= ((width - 1) / 4).floor();
-      }
-    }
-
-    switch (type) {
-      case 'n': comma = true; type = 'g'; break;
-      case '%': scale = 100; suffix = '%'; type = 'f'; break;
-      case 'p': scale = 100; suffix = '%'; type = 'r'; break;
-      case 'b':
-      case 'o':
-      case 'x':
-      case 'X': if (symbol == '#') prefix = '0' + type.toLowerCase(); break;
-      case 'c':
-      case 'd': integer = true; precision = 0; break;
-      case 's': scale = -1; type = 'r'; break;
-    }
-
-    if (symbol == '\$') {
-      prefix = localeCurrency[0];
-      suffix = localeCurrency[1];
-    }
-
-    // If no precision is specified for r, fallback to general notation.
-    if (type == 'r' && precision == null) {
-      type = 'g';
-    }
-
-    // Ensure that the requested precision is in the supported range.
-    if (precision != null) {
-      if (type == 'g') {
-        precision = math.max(1, math.min(21, precision));
-      } else if (type == 'e' || type == 'f') {
-        precision = math.max(0, math.min(20, precision));
-      }
-    }
-
-    NumberFormatFunction formatFunction = _getFormatFunction(type);
-
-    var zcomma = (zfill != null) && comma;
-
-    return (value) {
-      var fullSuffix = suffix;
-
-      // Return the empty string for floats formatted as ints.
-      if (integer && (value % 1) > 0) return '';
-
-      // Convert negative to positive, and record the sign prefix.
-      var negative;
-      if (value < 0 || value == 0 && 1 / value < 0) {
-        value = -value;
-        negative = '-';
-      } else {
-        negative = sign;
-      }
-
-      // Apply the scale, computing it from the value's exponent for si
-      // format.  Preserve the existing suffix, if any, such as the
-      // currency symbol.
-      if (scale < 0) {
-        FormatPrefix unit = new FormatPrefix(value,
-            (precision != null) ? precision : 0);
-        value = unit.scale(value);
-        fullSuffix = unit.symbol + suffix;
-      } else {
-        value *= scale;
-      }
-
-      // Convert to the desired precision.
-      if (precision != null) {
-        value = formatFunction(value, precision);
-      } else {
-        value = formatFunction(value);
-      }
-
-      // Break the value into the integer part (before) and decimal part
-      // (after).
-      var i = value.lastIndexOf('.'),
-          before = i < 0 ? value : value.substring(0, i),
-          after = i < 0 ? '' : localeDecimal + value.substring(i + 1);
-
-      // If the fill character is not '0', grouping is applied before
-      //padding.
-      if (zfill == null && comma) {
-        before = formatGroup(before);
-      }
-
-      var length = prefix.length + before.length + after.length +
-              (zcomma ? 0 : negative.length),
-          padding = length < width ? new List.filled(
-              (length = width - length + 1), '').join(fill) : '';
-
-      // If the fill character is '0', grouping is applied after padding.
-      if (zcomma) {
-        before = formatGroup(padding + before);
-      }
-
-      // Apply prefix.
-      negative += prefix;
-
-      // Rejoin integer and decimal parts.
-      value = before + after;
-
-      // Apply any padding and alignment attributes before returning the string.
-      return (align == '<' ? negative + value + padding
-          : align == '>' ? padding + negative + value
-          : align == '^' ? padding.substring(0, length >>= 1) + negative +
-              value + padding.substring(length)
-          : negative + (zcomma ? value : padding + value)) + fullSuffix;
-    };
-  }
-
-  // Gets the format function by given type.
-  NumberFormatFunction _getFormatFunction(String type) {
-    switch(type) {
-      case 'b':
-        return (num x, [int p = 0]) => x.toInt().toRadixString(2);
-      case 'c':
-        return (num x, [int p = 0]) => new String.fromCharCodes([x]);
-      case 'o':
-        return (num x, [int p = 0]) => x.toInt().toRadixString(8);
-      case 'x':
-        return (num x, [int p = 0]) => x.toInt().toRadixString(16);
-      case 'X':
-        return (num x, [int p = 0]) =>
-            x.toInt().toRadixString(16).toUpperCase();
-      case 'g':
-        return (num x, [int p = 1]) => x.toStringAsPrecision(p);
-      case 'e':
-        return (num x, [int p = 0]) => x.toStringAsExponential(p);
-      case 'f':
-        return (num x, [int p = 0]) => x.toStringAsFixed(p);
-      case 'r':
-      default:
-        return (num x, [int p = 0]) => x.toString();
-    }
-  }
-}