Class EBNFUnitFormat

java.lang.Object
tech.units.indriya.format.AbstractUnitFormat
tech.units.indriya.format.EBNFUnitFormat
All Implemented Interfaces:
javax.measure.format.UnitFormat
public class EBNFUnitFormat extends AbstractUnitFormat

This class represents the local neutral format.

Here is the grammar for Units in Extended Backus-Naur Form (EBNF)

Note that the grammar has been left-factored to be suitable for use by a top-down parser generator such as JavaCC

Lexical Entities:
<sign> := "+" | "-"
<digit> := "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"
<superscript_digit> := "⁰" | "¹" | "²" | "³" | "⁴" | "⁵" | "⁶" | "⁷" | "⁸" | "⁹"
<integer> := (<digit>)+
<number> := (<sign>)? (<digit>)* (".")? (<digit>)+ (("e" | "E") (<sign>)? (<digit>)+)?
<exponent> := ( "^" ( <sign> )? <integer> )
| ( "^(" (<sign>)? <integer> ( "/" (<sign>)? <integer> )? ")" )
| ( <superscript_digit> )+
<initial_char> := ? Any Unicode character excluding the following: ASCII control invalid input: '&' whitespace (\u0000 - \u0020), decimal digits '0'-'9', '(' (\u0028), ')' (\u0029), '*' (\u002A), '+' (\u002B), '-' (\u002D), '.' (\u002E), '/' (\u005C), ':' (\u003A), '^' (\u005E), '²' (\u00B2), '³' (\u00B3), '·' (\u00B7), '¹' (\u00B9), '⁰' (\u2070), '⁴' (\u2074), '⁵' (\u2075), '⁶' (\u2076), '⁷' (\u2077), '⁸' (\u2078), '⁹' (\u2079) ?
<unit_identifier> := <initial_char> ( <initial_char> | <digit> )*
Non-Terminals:
<unit_expr> := <compound_expr>
<compound_expr> := <add_expr> ( ":" <add_expr> )*
<add_expr> := ( <number> <sign> )? <mul_expr> ( <sign> <number> )?
<mul_expr> := <exponent_expr> ( ( ( "*" | "·" ) <exponent_expr> ) | ( "/" <exponent_expr> ) )*
<exponent_expr> := ( <atomic_expr> ( <exponent> )? )
| (<integer> "^" <atomic_expr>)
| ( ( "log" ( <integer> )? ) | "ln" ) "(" <add_expr> ")" )
<atomic_expr> := <number>
| <unit_identifier>
| ( "(" <add_expr> ")" )
Since:
1.0
Version:
1.1, $Date: 2018-04-05 $
Author:
Eric Russell, Werner Keil

  • Method Details

    • getInstance

      public static EBNFUnitFormat getInstance()
      Returns the instance for the current default locale (non-ascii characters are allowed)

    • getInstance

      public static EBNFUnitFormat getInstance(SymbolMap symbols)
      Returns an instance for the given symbol map.

    • getSymbols

      protected SymbolMap getSymbols()
      Get the symbol map used by this instance to map between
      invalid reference 
      Unit
      s and Strings, etc...
      Specified by:
      getSymbols in class AbstractUnitFormat
      Returns:
      SymbolMap the current symbol map

    • format

      public Appendable format(javax.measure.Unit<?> unit, Appendable appendable) throws IOException
      Description copied from class: AbstractUnitFormat
      Formats the specified unit.
      Specified by:
      format in interface javax.measure.format.UnitFormat
      Specified by:
      format in class AbstractUnitFormat
      Parameters:
      unit - the unit to format.
      appendable - the appendable destination.
      Returns:
      The appendable destination passed in as appendable, with formatted text appended.
      Throws:
      IOException - if an error occurs.

    • parse

      protected javax.measure.Unit<? extends javax.measure.Quantity<?>> parse(CharSequence csq, ParsePosition cursor) throws javax.measure.format.ParserException
      Description copied from class: AbstractUnitFormat
      Parses a portion of the specified CharSequence from the specified position to produce a unit. If there is no unit to parse AbstractUnit.ONE is returned.
      Specified by:
      parse in class AbstractUnitFormat
      Parameters:
      csq - the CharSequence to parse.
      cursor - the cursor holding the current parsing index.
      Returns:
      the unit parsed from the specified character sub-sequence.
      Throws:
      javax.measure.format.ParserException

    • parse

      protected javax.measure.Unit<?> parse(CharSequence csq, int index) throws IllegalArgumentException
      Description copied from class: AbstractUnitFormat
      Parses a portion of the specified CharSequence from the specified position to produce a unit. If there is no unit to parse AbstractUnit.ONE is returned.
      Specified by:
      parse in class AbstractUnitFormat
      Parameters:
      csq - the CharSequence to parse.
      index - the current parsing index.
      Returns:
      the unit parsed from the specified character sub-sequence.
      Throws:
      IllegalArgumentException - if any problem occurs while parsing the specified character sequence (e.g. illegal syntax).

    • parse

      public javax.measure.Unit<?> parse(CharSequence csq) throws javax.measure.format.ParserException
      Throws:
      javax.measure.format.ParserException

    • isLocaleSensitive

      public boolean isLocaleSensitive()