Quipper.Utils.CommandLine

This module provides some functions that are useful in the processing of command line options, and that are shared between several algorithms.

Option processing

optfail :: String -> IO a

Exit with an error message after a command line error. This also outputs information on where to find command line help.

parse_int :: Integral r => String -> Maybe r

Parse a string to an integer, or return Nothing on failure.

parse_list_int :: String -> Maybe [Int]

Parse a string to a list of integers, or return Nothing on failure.

parse_double :: String -> Maybe Double

Parse a string to a Double, or return Nothing on failure.

match_enum :: [(String, a)] -> String -> [(String, a)]

In an association list, find the key that best matches the given string. If one key matches exactly, return the corresponding key-value pair. Otherwise, return a list of all key-value pairs whose key have the given string as a prefix. This list could be of length 0 (no match), 1 (unique match), or greater (ambiguous key). Note: the keys in the association list must be lower case. The input string is converted to lower case as well, resulting in case-insensitive matching.

show_enum :: String -> [(String, a)] -> String

Pretty-print a list of possible values for a parameter. The first argument is the name of the parameter, and the second argument is its enumeration.