Chars

• <(x:char, y:char) -> boolean
• <=(c1:char, c2:char) -> boolean
• >(x:char, y:char) -> boolean
• >=(x:char, y:char) -> boolean
• alpha?(c:char) -> boolean [XL]
• digit?(c:char) -> boolean [XL]
• integer!(c:char) -> integer
• lower?(c:char) -> boolean [XL]
• space?(c:char) -> boolean [XL]
• string!(self:char) -> string [XL]

In CLAIRE chars are true object (i.e. not primitive) that hold an 8 bit value, one can obtain this value with integer!(c:char) and make a char from an integer i with char!(i:integer).

[XL] Starting with XL CLAIRE the internal 8 bit value is stored as an unsigned char (vs. signed char in CLAIRE 3) such the composition char!(integer!()) is actually the identity for all possible existing char in the system. If their is no char that hold a given value n then char!(n) will produce an error.

<(x:char, y:char) -> boolean

returns true if ASCII code of x is lower than ASCII code of y

<=(c1:char, c2:char) -> boolean

returns true if ASCII code of x is lower or equal to ASCII code of y

>(x:char, y:char) -> boolean

returns true if ASCII code of x is greater than ASCII code of y

>=(x:char, y:char) -> boolean

returns true if ASCII code of x is greater or equal to ASCII code of y

alpha?(c:char) -> boolean

alpha?(c) returns true when the char c is in the range ('a' .. 'z', 'A' .. 'Z').

digit?(c:char) -> boolean

digit?(c) returns true if c is in the interval ('0' .. '9').

integer!(c:char) -> integer

integer!(c) returns the ASCII code of c

lower?(c:char) -> boolean

lower?(c) returns true if c is not in ('A' .. 'Z').

space?(c:char) -> boolean

space?(c) returns true if c is in {' ', '\t', '\r', '\n'}.

space?(' ') -> true  space?('\n') -> true  space?('t') -> false

string!(self:char) -> string

make a new string from a a char self. The returned string always has of length of 1. One could use make_string to create a string of a given length filled with a given char.