--- layout: default title: "Characters" parent: Primitive ancestor: Funcons-beta --- [Funcons-beta] : [Characters.cbs] ----------------------------- ### Characters 
[
  Type     characters                          Alias chars
  Datatype unicode-characters                  Alias unicode-chars
  Type     unicode-points
  Funcon   unicode-character                   Alias unicode-char
  Funcon   unicode-point                       Alias unicode
  Type     basic-multilingual-plane-characters Alias bmp-chars
  Type     basic-multilingual-plane-points
  Type     iso-latin-1-characters              Alias latin-1-chars
  Type     iso-latin-1-points
  Type     ascii-characters                    Alias ascii-chars
  Type     ascii-points
  Funcon   ascii-character                     Alias ascii-char
  Funcon   utf-8
  Funcon   utf-16
  Funcon   utf-32
  Funcon   backspace
  Funcon   horizontal-tab
  Funcon   line-feed
  Funcon   form-feed
  Funcon   carriage-return
  Funcon   double-quote
  Funcon   single-quote
  Funcon   backslash
]
Built-in Type
  characters <: values
Literal characters can be written 'C' where C is any visible character other than a single-quote or backslash character, which need to be escaped as '\'' and '\\'. 
Alias
  chars = characters
#### Unicode character set The set of Unicode characters and allocated points is open to extension. See https://en.wikipedia.org/wiki/Plane_(Unicode) 
Built-in Datatype
  unicode-characters <: characters
Alias
  unicode-chars = unicode-characters
Built-in Type
  unicode-points <: bounded-integers(0, unsigned-bit-vector-maximum(21))
Built-in Funcon
  unicode-character(_:unicode-points) : unicode-characters
Alias
  unicode-char = unicode-character
The values in unicode-characters are the values of unicode-character(UP:unicode-points). 
Funcon
  unicode-point(_:unicode-characters) : =>unicode-points
Alias
  unicode = unicode-point
Rule
  unicode-point(unicode-character(UP:unicode-points)) ~> UP
#### Unicode basic multilingual plane The set of Unicode BMP characters and allocated points is open to extension. 
Built-in Datatype
  basic-multilingual-plane-characters <: unicode-characters
Alias
  bmp-chars = basic-multilingual-plane-characters
Built-in Type
  basic-multilingual-plane-points <:
    bounded-integers(0, unsigned-bit-vector-maximum(17))
The values in basic-multilingual-plane-characters are the values of unicode-character(BMPP:basic-multilingual-plane-points). #### ISO Latin-1 character set 
Built-in Datatype
  iso-latin-1-characters <: basic-multilingual-plane-characters
Alias
  latin-1-chars = iso-latin-1-characters
Type
  iso-latin-1-points ~> bounded-integers(0, unsigned-bit-vector-maximum(8))
The values in iso-latin-1-characters are the values of unicode-character(ILP:iso-latin-1-points). #### ASCII character set 
Built-in Type
  ascii-characters <: iso-latin-1-characters
Alias
  ascii-chars = ascii-characters
Type
  ascii-points ~> bounded-integers(0, unsigned-bit-vector-maximum(7))
The values in ascii-characters are the values of unicode-character(AP:ascii-points). 
Funcon
  ascii-character(_:strings) : =>ascii-characters?
Alias
  ascii-char = ascii-character
ascii-character"C" takes a string. When it consists of a single ASCII character C it gives the character, otherwise ( ). 
Rule
  ascii-character[C:ascii-characters] ~> C
Rule
  C : ~ ascii-characters
  ------------------------------------
  ascii-character[C:characters] ~> ( )
Rule
  length(C*) =/= 1
  --------------------------------------
  ascii-character[C*:characters*] ~> ( )
#### Character point encodings See https://en.wikipedia.org/wiki/Character_encoding 
Built-in Funcon
  utf-8(_:unicode-points) : =>(bytes, (bytes, (bytes, bytes?)? )? )
Built-in Funcon
  utf-16(_:unicode-points) : =>(bit-vectors(16), (bit-vectors(16))? )
Built-in Funcon
  utf-32(_:unicode-points) : =>bit-vectors(32)
#### Control characters 
Funcon
  backspace : =>ascii-characters 
    ~> unicode-character(hexadecimal-natural"0008")
Funcon
  horizontal-tab : =>ascii-characters 
    ~> unicode-character(hexadecimal-natural"0009")
Funcon
  line-feed : =>ascii-characters 
    ~> unicode-character(hexadecimal-natural"000a")
Funcon
  form-feed : =>ascii-characters 
    ~> unicode-character(hexadecimal-natural"000c")
Funcon
  carriage-return : =>ascii-characters 
    ~> unicode-character(hexadecimal-natural"000d")
Funcon
  double-quote : =>ascii-characters 
    ~> unicode-character(hexadecimal-natural"0022")
Funcon
  single-quote : =>ascii-characters 
    ~> unicode-character(hexadecimal-natural"0027")
Funcon
  backslash : =>ascii-characters 
    ~> unicode-character(hexadecimal-natural"005c")
____ From the [PLanCompS Project] | [CBS-beta issues...] | [Suggest an improvement...] [Characters.cbs]: Characters.cbs "CBS SOURCE FILE" [Funcons-beta]: /CBS-beta/docs/Funcons-beta "FUNCONS-BETA" [Unstable-Funcons-beta]: /CBS-beta/docs/Unstable-Funcons-beta "UNSTABLE-FUNCONS-BETA" [Languages-beta]: /CBS-beta/docs/Languages-beta "LANGUAGES-BETA" [Unstable-Languages-beta]: /CBS-beta/docs/Unstable-Languages-beta "UNSTABLE-LANGUAGES-BETA" [CBS-beta]: /CBS-beta "CBS-BETA" [PLanCompS Project]: https://plancomps.github.io "PROGRAMMING LANGUAGE COMPONENTS AND SPECIFICATIONS PROJECT HOME PAGE" [CBS-beta issues...]: https://github.com/plancomps/CBS-beta/issues "CBS-BETA ISSUE REPORTS ON GITHUB" [Suggest an improvement...]: mailto:plancomps@gmail.com?Subject=CBS-beta%20-%20comment&Body=Re%3A%20CBS-beta%20specification%20at%20Values/Primitive/Characters/Characters.cbs%0A%0AComment/Query/Issue/Suggestion%3A%0A%0A%0ASignature%3A%0A "GENERATE AN EMAIL TEMPLATE"