class Label in Tinman.Core.Formatting

A label string with format value tags.

sealed class

Label

Remarks

The Grammar of a label is as follows:

label         := (text | tag)* ;

!tag          := '{' '0'..'9'+ expr? '}' ;
text          := text-char+ ;

!expr         := expr-choice | expr-plural | expr-singular ;
text-char     := '{{' | ]{[ ;

expr-choice   := '>' argument ('|' argument)* ;
expr-plural   := '?' argument ('|' argument)? ;
expr-singular := '!' argument ('|' argument)? ;

!argument     := (char+ | '#')* ;

char          := ]}#\\|[ | '\\' [}#\\|] ;

Here are some examples:

• Simple label without tags:
  'Hello Mr. Label!'
• Label with simple tag:
  'Hello {0} Label!'
  with {0} = 'Ms.' evaluates to 'Hello Ms. Label!'
  Simple tags are replaced by the given values, without applying any further logic.
• Label with conditional tag (three choices):
  'Hello {0:Mr.|Mrs.|Ms.} Label!'
  with {0} = '1' evaluates to 'Hello Mrs. Label!'
  Each conditional tag interprets the given value as a zero-based integer index into its list of choices and then gets replaced by the respective choice value.
• Label with conditional tags with choice referencing tag value:
  'Found {0:no|one|#} file{0:s||s} in {1:#|one|#} director{1:ies|y|ies}!'
  with {0}, {1} = '0' evaluates to 'Found no files in 0 directories!'
  with {0}, {1} = '1' evaluates to 'Found one file in one directory!'
  with {0}, {1} = '2' evaluates to 'Found 2 files in 2 directories!'
  The # in a tag choice will insert the tag value itself.
• Label with singular / plural choice tags:
  'Found {0!one|#} file{0?s} in {1!one|#} director{1!y|ies}!'
  where {0!one|#} is the compact form of {0:#|one|#}
  where {0!one} is the compact form of {0:|one|}
  where {0?s|#} is the compact form of {0:s|#|s}
  where {0?s} is the compact form of {0:s||s}
  with {0}, {1} = '0' evaluates to 'Found 0 files in 0 directories!'
  with {0}, {1} = '1' evaluates to 'Found one file in one directory!'
  with {0}, {1} = '2' evaluates to 'Found 2 files in 2 directories!'
  

The following escape sequences are available:

• {{ as replacement of {
• || as replacement of |
• }} as replacement of }
• ## as replacement of #

For evaluation, tag values are interpreted as integer values according to these rules:

• Bool:
  true:= 1, false:= 0
• Char:
  '0':= 0, ... '9':= 9
• Int:
  The value itself.
• Num:
  The rounded value. See Round.
• Obj:
  null:= 0, 1 otherwise.
• Str:
  Str:
  For null, empty and string containing only whitespace characters: 0, otherwise 1.

Public / Constants

Any

A label that consists of a single placeholder: {0}.

public static readonly field	Any
type	Label

Public / Attributes

Format

Formats this label with custom tag values.

public property	Format { get }
type	LabelFormat
value		The label formatter.

Public / Methods

From

Parses a label.

public static method	From (string source)
type	Label
params	source	[not-null]	The label source code.
returns		[not-null]	The parsed label.

Exceptions:

• ValidatingException:
  If the syntax of source is invalid.

ToString

public override method	ToString ()
type	string