Hledger.Utils.String

String formatting helpers, starting to get a bit out of control.

Documentation

takeEnd :: Int -> [a] -> [a]

Take elements from the end of a list.

misc

lowercase :: String -> String

uppercase :: String -> String

underline :: String -> String

stripbrackets :: String -> String

quoteIfNeeded :: String -> String

Double-quote this string if it contains whitespace, single quotes or double-quotes, escaping the quotes as needed.

singleQuoteIfNeeded :: String -> String

Single-quote this string if it contains whitespace or double-quotes. Does not work for strings containing single quotes.

quoteForCommandLine :: String -> String

Try to single- and backslash-quote a string as needed to make it usable as an argument on a (sh/bash) shell command line. At least, well enough to handle common currency symbols, like $. Probably broken in many ways.

>>> quoteForCommandLine "a"
"a"
>>> quoteForCommandLine "\""
"'\"'"
>>> quoteForCommandLine "$"
"'\\$'"

words' :: String -> [String]

Quote-aware version of words - don't split on spaces which are inside quotes. NB correctly handles "a'b" but not "'a'". Can raise an error if parsing fails.

unwords' :: [String] -> String

Quote-aware version of unwords - single-quote strings which contain whitespace

stripAnsi :: String -> String

Strip ANSI escape sequences from a string.

>>> stripAnsi "\ESC[31m-1\ESC[m"
"-1"

single-line layout

strip :: String -> String

Remove leading and trailing whitespace.

lstrip :: String -> String

Remove leading whitespace.

rstrip :: String -> String

Remove trailing whitespace.

strip1Char :: Char -> Char -> String -> String

Strip the given starting and ending character from the start and end of a string if both are present.

stripBy :: (Char -> Bool) -> String -> String

Strip a run of zero or more characters matching the predicate from the start and end of a string.

strip1By :: (Char -> Bool) -> String -> String

Strip a single balanced enclosing pair of a character matching the predicate from the start and end of a string.

chomp :: String -> String

Remove all trailing newlines/carriage returns.

chomp1 :: String -> String

Remove all trailing newline/carriage returns, leaving just one trailing newline.

singleline :: String -> String

Remove consecutive line breaks, replacing them with single space

elideLeft :: Int -> String -> String

elideRight :: Int -> String -> String

formatString :: Bool -> Maybe Int -> Maybe Int -> String -> String

Clip and pad a string to a minimum & maximum width, andor leftright justify it. Works on multi-line strings too (but will rewrite non-unix line endings).

wide-character-aware layout

charWidth :: Char -> Int

Returns width of a character in a monospace font: 0 for a combining character, 1 for a regular character, 2 for an East Asian wide character. Ambiguous characters are treated as width 1.

strWidth :: String -> Int

Alias for realLength.

strWidthAnsi :: String -> Int

Like strWidth, but also strips ANSI escape sequences before calculating the width.

This is no longer used in code, as widths are calculated before adding ANSI escape sequences, but is being kept around for now.

takeWidth :: Int -> String -> String

Double-width-character-aware string truncation. Take as many characters as possible from a string without exceeding the specified width. Eg takeWidth 3 "りんご" = "り".