Summary
ReadArgs provides the @readArgs@ IO action, which lets you tell the compiler to parse the command line arguments to fit the type signature you give. For example @(a :: Int, b :: String, c :: Float) <- readArgs@ would parse the first runtime argument as an @Int@, the second as a @String@ (no quotes required) and the third as a @Float@. If the runtime arguments are incompatible with the type signature, then a simple usage statement is given of the types needed. Continuing the previous example, if it was used in a program named @Example@, the error message for the above action would be: @ usage: Example Int String Float @ Any type that has both @Typeable@ and @Read@ instances can be used. @Char@, @String@, and @Text@ are handled specially so that command line arguments for both do not require quotes (as their @Read@ instances do). A special instance is provided for @FilePath@ so that no constructor or quotes are required. @readArgs@ also supports optional arguments and variadic arguments. Optional arguments are specified using @Maybe@, and variadic arguments using a list. @(a :: Int, b :: Maybe String, c :: [Float]) <- readArgs@ would successfully parse any of the following sets of command line arguments: @ Example 1 Example 1 2 3 4 Example 1 foo Example 1 foo 2 3 4 @ But not @ Example Example foo Example 1.0 @ Usage statements for optional and variadic arguments use command-line parlance: @ usage: Example Int [String] [Float..] @ Note that both optional and variadic parsers are greedy by default (so @Example 1 2 3 4@ was parsed as @(1, "2", [3.0,4.0])@. They may both be made non-greedy through use of the @NonGreedy@ constructor: @ ( a :: Int , NonGreedy b :: NonGreedy Maybe String , NonGreedy c :: NonGreedy [] Float ) <- readArgs @
Versions
v1.2.3 :: 0/1.2.3 :: gentoo
- Modified
- License
- BSD
- Keywords
- ~amd64 ~x86
- USE flags
- doc hscolour profile test
USE flags
General
- doc
- Add extra documentation (API, Javadoc, etc). It is recommended to enable per package instead of globally
- hscolour
- Include coloured haskell sources to generated documentation (dev-haskell/hscolour)
- profile
- Add support for software performance analysis (will likely vary from ebuild to ebuild)
- test
- Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently)
Dependencies
dev-haskell / cabal : A framework for packaging Haskell software
dev-haskell / haddock : A documentation-generation tool for Haskell libraries
dev-haskell / hscolour : Colourise Haskell code
dev-haskell / hspec : A Testing Framework for Haskell
dev-haskell / system-filepath : High-level, byte-based file and directory path manipulations (deprecated)
dev-haskell / text : An efficient packed Unicode text type
Runtime Dependencies
dev-haskell / system-filepath : High-level, byte-based file and directory path manipulations (deprecated)
dev-haskell / text : An efficient packed Unicode text type
Change logs
- Repository mirror & CI · gentoo
Merge updates from master - Sergei Trofimovich · gentoo
dev-haskell/readargs: drop old
Package-Manager: Portage-3.0.6, Repoman-3.0.1 Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org> - Repository mirror & CI · gentoo
Merge updates from master - Michał Górny · gentoo
*/*: Inline mirror://hackage and update URIs
This change inlines mirror://hackage in all ebuilds, and updates URIs to the modern form (old URIs redirect to that). The change has been made using the following command: find -name '*.ebuild' -exec sed -r -i \ -e 's@mirror://hackage/@https://hackage.haskell.org/@g' \ -e 's@https://hackage.haskell.org/packages/archive/([^/]*)/([^/]*)/@https://hackage.haskell.org/package/\1-\2/@g' \ -e '/hackage\.haskell\.org/s@\$\{PN}-\$\{PV}@${P}@g' \ -e '/hackage\.haskell\.org/s@\$\{MY_PN}-\$\{PV}@${MY_P}@g' \ -e '/hackage\.haskell\.org/s@\$\{PN}-\$\{MY_PV}@${MY_P}@g' \ {} + Signed-off-by: Michał Górny <mgorny@gentoo.org> - Robin H. Johnson · gentoo
Drop $Id$ per council decision in bug #611234.
Signed-off-by: Robin H. Johnson <robbat2@gentoo.org> - Sergei Trofimovich · gentoo
dev-haskell/readargs: bump up to 1.2.3
Package-Manager: Portage-2.3.3, Repoman-2.3.1 - Sergei Trofimovich · gentoo
dev-haskell/readargs: drop old
Package-Manager: portage-2.2.28 - Justin Lecher · gentoo
Use https by default
Signed-off-by: Justin Lecher <jlec@gentoo.org> - Robin H. Johnson · gentoo
proj/gentoo: Initial commit
This commit represents a new era for Gentoo: Storing the gentoo-x86 tree in Git, as converted from CVS. This commit is the start of the NEW history. Any historical data is intended to be grafted onto this point. Creation process: 1. Take final CVS checkout snapshot 2. Remove ALL ChangeLog* files 3. Transform all Manifests to thin 4. Remove empty Manifests 5. Convert all stale $Header$/$Id$ CVS keywords to non-expanded Git $Id$ 5.1. Do not touch files with -kb/-ko keyword flags. Signed-off-by: Robin H. Johnson <robbat2@gentoo.org> X-Thanks: Alec Warner <antarus@gentoo.org> - did the GSoC 2006 migration tests X-Thanks: Robin H. Johnson <robbat2@gentoo.org> - infra guy, herding this project X-Thanks: Nguyen Thai Ngoc Duy <pclouds@gentoo.org> - Former Gentoo developer, wrote Git features for the migration X-Thanks: Brian Harring <ferringb@gentoo.org> - wrote much python to improve cvs2svn X-Thanks: Rich Freeman <rich0@gentoo.org> - validation scripts X-Thanks: Patrick Lauer <patrick@gentoo.org> - Gentoo dev, running new 2014 work in migration X-Thanks: Michał Górny <mgorny@gentoo.org> - scripts, QA, nagging X-Thanks: All of other Gentoo developers - many ideas and lots of paint on the bikeshed