mirror of
https://github.com/idris-lang/Idris2.git
synced 2024-12-18 00:31:57 +03:00
103 lines
2.7 KiB
Idris
103 lines
2.7 KiB
Idris
module Data.String.Extra
|
|
|
|
import Data.Strings
|
|
|
|
%default total
|
|
|
|
|
|
infixl 5 +>
|
|
infixr 5 <+
|
|
|
|
||| Adds a character to the end of the specified string.
|
|
|||
|
|
||| ```idris example
|
|
||| strSnoc "AB" 'C'
|
|
||| ```
|
|
||| ```idris example
|
|
||| strSnoc "" 'A'
|
|
||| ```
|
|
public export
|
|
strSnoc : String -> Char -> String
|
|
strSnoc s c = s ++ (singleton c)
|
|
|
|
||| Alias of `strSnoc`
|
|
|||
|
|
||| ```idris example
|
|
||| "AB" +> 'C'
|
|
||| ```
|
|
public export
|
|
(+>) : String -> Char -> String
|
|
(+>) = strSnoc
|
|
|
|
||| Alias of `strCons`
|
|
|||
|
|
||| ```idris example
|
|
||| 'A' <+ "AB"
|
|
||| ```
|
|
public export
|
|
(<+) : Char -> String -> String
|
|
(<+) = strCons
|
|
|
|
||| Take the first `n` characters from a string. Returns the whole string
|
|
||| if it's too short.
|
|
public export
|
|
take : (n : Nat) -> (input : String) -> String
|
|
take n str = substr Z n str
|
|
|
|
||| Take the last `n` characters from a string. Returns the whole string
|
|
||| if it's too short.
|
|
public export
|
|
takeLast : (n : Nat) -> (input : String) -> String
|
|
takeLast n str with (length str)
|
|
takeLast n str | len with (isLTE n len)
|
|
takeLast n str | len | Yes prf = substr (len `minus` n) len str
|
|
takeLast n str | len | No contra = str
|
|
|
|
||| Remove the first `n` characters from a string. Returns the empty string if
|
|
||| the input string is too short.
|
|
public export
|
|
drop : (n : Nat) -> (input : String) -> String
|
|
drop n str = substr n (length str) str
|
|
|
|
||| Remove the last `n` characters from a string. Returns the empty string if
|
|
||| the input string is too short.
|
|
public export
|
|
dropLast : (n : Nat) -> (input : String) -> String
|
|
dropLast n str = reverse (drop n (reverse str))
|
|
|
|
||| Remove the first and last `n` characters from a string. Returns the empty
|
|
||| string if the input string is too short.
|
|
public export
|
|
shrink : (n : Nat) -> (input : String) -> String
|
|
shrink n str = dropLast n (drop n str)
|
|
|
|
||| Concatenate the strings from a `Foldable` containing strings, separated by
|
|
||| the given string.
|
|
public export
|
|
join : (sep : String) -> Foldable t => (xs : t String) -> String
|
|
join sep xs = drop (length sep)
|
|
(foldl (\acc, x => acc ++ sep ++ x) "" xs)
|
|
|
|
||| Get a character from a string if the string is long enough.
|
|
public export
|
|
index : (n : Nat) -> (input : String) -> Maybe Char
|
|
index n str with (unpack str)
|
|
index n str | [] = Nothing
|
|
index Z str | (x :: xs) = Just x
|
|
index (S n) str | (x :: xs) = index n str | xs
|
|
|
|
||| Produce a string by repeating the character `c` `n` times.
|
|
public export
|
|
replicate : (n : Nat) -> (c : Char) -> String
|
|
replicate n c = pack $ replicate n c
|
|
|
|
||| Indent a given string by `n` spaces.
|
|
public export
|
|
indent : (n : Nat) -> String -> String
|
|
indent n x = replicate n ' ' ++ x
|
|
|
|
||| Indent each line of a given string by `n` spaces.
|
|
public export
|
|
indentLines : (n : Nat) -> String -> String
|
|
indentLines n str = unlines $ map (indent n) $ lines str
|