Character type

For built-In functions and operations on characters, see stdchar.

Type annotation

Characters are annotated with Char.

// Language: Clean

expr :: Char
expr =  'a'

Character Literals

Character literals are created by enclosing a character within single quotation marks ('...').

// Language: Clean

x :: Char
x =  '1'
x =  'a'
x =  'A'
x =  '+'

%%

Using Character Literal as Pattern

Example A

// Language: Clean

exampleA :: Char -> Bool
exampleA    'G'  =  True
exampleA    _    =  False

Python equivalent:

# Python

def exampleA(arg: str) -> bool:
    match arg:
        case "G":
            return True
        case _:
            return False

Example B

// Language: Clean

exampleB :: Char -> Bool
exampleB    'G'  =  True
exampleB    'g'  =  True
exampleB    _    =  False

Python equivalent:

# Python

def exampleB(arg: str) -> bool:
    match arg:
        case "G":
            return True
        case "g":
            return True
        case _:
            return False

Example C

// Language: Clean

exampleC :: Char Char -> Bool
exampleC    'G'  'G'  =  True
exampleC    _    _    =  False

Python equivalent:

# Python

def exampleC(
    argA: str, 
    argB: str
) -> bool:
    match (argA, argB):
        case ("G", "G"):
            return True
        case _:
            return False

Example D

// Language: Clean

exampleD :: Char Char -> Bool
exampleD    'G'  'G'  =  True
exampleD    'G'  'g'  =  True
exampleD    'g'  'G'  =  True
exampleD    'g'  'g'  =  True
exampleD    _    _    =  False

Python equivalent:

# Python

def exampleD(
    argA: str, 
    argB: str
) -> bool:
    match (argA, argB):
        case ("G", "G"):
            return True
        case ("G", "g"):
            return True
        case ("g", "G"):
            return True
        case ("g", "g"):
            return True
        case _:
            return False

%%