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author | V3n3RiX <venerix@redcorelinux.org> | 2018-07-14 21:03:06 +0100 |
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committer | V3n3RiX <venerix@redcorelinux.org> | 2018-07-14 21:03:06 +0100 |
commit | 8376ef56580626e9c0f796d5b85b53a0a1c7d5f5 (patch) | |
tree | 7681bbd4e8b05407772df40a4bf04cbbc8afc3fa /dev-haskell/optparse-applicative/metadata.xml | |
parent | 30a9caf154332f12ca60756e1b75d2f0e3e1822d (diff) |
gentoo resync : 14.07.2018
Diffstat (limited to 'dev-haskell/optparse-applicative/metadata.xml')
-rw-r--r-- | dev-haskell/optparse-applicative/metadata.xml | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/dev-haskell/optparse-applicative/metadata.xml b/dev-haskell/optparse-applicative/metadata.xml new file mode 100644 index 000000000000..a9f0962e5dcf --- /dev/null +++ b/dev-haskell/optparse-applicative/metadata.xml @@ -0,0 +1,72 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd"> +<pkgmetadata> + <maintainer type="project"> + <email>haskell@gentoo.org</email> + <name>Gentoo Haskell</name> + </maintainer> + <longdescription> + Here is a simple example of an applicative option parser: + + @ + data Sample = Sample + &#x20; &#x7b; hello :: String + &#x20; , quiet :: Bool &#x7d; + + sample :: Parser Sample + sample = Sample + &#x20; \<$\> strOption + &#x20; ( long \"hello\" + &#x20; & metavar \"TARGET\" + &#x20; & help \"Target for the greeting\" ) + &#x20; \<*\> switch + &#x20; ( long \"quiet\" + &#x20; & help \"Whether to be quiet\" ) + @ + + The parser is built using applicative style starting from a set of basic + combinators. In this example, @hello@ is defined as an 'option' with a + @String@ argument, while @quiet@ is a boolean 'flag' (called 'switch'). + + A parser can be used like this: + + @ + greet :: Sample -> IO () + greet (Sample h False) = putStrLn $ \"Hello, \" ++ h + greet _ = return () + + main :: IO () + main = execParser opts \>\>= greet + &#x20; where + &#x20; opts = info (helper \<*\> sample) + &#x20; ( fullDesc + &#x20; & progDesc \"Print a greeting for TARGET\" + &#x20; & header \"hello - a test for optparse-applicative\" ) + @ + + The @greet@ function is the entry point of the program, while @opts@ is a + complete description of the program, used when generating a help text. The + 'helper' combinator takes any parser, and adds a @help@ option to it (which + always fails). + + The @hello@ option in this example is mandatory (since it doesn't have a + default value), so running the program without any argument will display a + help text: + + >hello - a test for optparse-applicative + > + >Usage: hello --hello TARGET [--quiet] + > Print a greeting for TARGET + > + >Available options: + > -h,--help Show this help text + > --hello TARGET Target for the greeting + > --quiet Whether to be quiet + + containing a short usage summary, and a detailed list of options with + descriptions. + </longdescription> + <upstream> + <remote-id type="github">pcapriotti/optparse-applicative</remote-id> + </upstream> +</pkgmetadata> |