\n 如何在 haskell 的字符列表中工作

Question

right now I have a String equal to "...\n...\n..." . In my code I want to write this as a list (like ['a','b','c'] ), but how would this work with the \n? I checked in ghci if string == ['.','.','.','.','.','.','.','.','.'] and it said no, so does anyone know how I would write the \n's in a Char list, thank you.

Answer 1

A String is a list of Char acters, so "foo" and ['f', 'o', 'o'] are exactly the same.

For a new line character '\n' [wiki] you can escape this, so your string "...\n...\n..." is equivalent to:

['.', '.', '.', '\n', '.', '.', '.', '\n', '.', '.', '.']

Here '\n' is a single character, not two : it maps to an ASCII character with codepoint 0a as hexadecimal value ( 10 as decimal value). The compiler thus sees \n and replaces that with a single character.

You can thus for example filter with filter ('\n' /=) some_string to filter out new line characters from a String .