diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,30 @@ +Copyright (c)2012, Anders Claesson + +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + + * Redistributions in binary form must reproduce the above + copyright notice, this list of conditions and the following + disclaimer in the documentation and/or other materials provided + with the distribution. + + * Neither the name of Anders Claesson nor the names of other + contributors may be used to endorse or promote products derived + from this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. diff --git a/README.md b/README.md new file mode 100644 --- /dev/null +++ b/README.md @@ -0,0 +1,65 @@ +sloane +====== + +A command line interface to Sloane's On-Line Encyclopedia of Integer Sequences (OEIS) + +Install +------- + + $ cabal install sloane + +Usage +----- + + $ sloane --help + Search Sloane's On-Line Encyclopedia of Integer Sequences + + sloane [OPTIONS] SEARCH-TERMS + + Common flags: + -k --keys=KEYS Keys of fields to print, http://oeis.org/eishelp1.html + (default: SN) + -a --all Print all fields + -n --limit=INT Limit the number of entries retrieved (default: 5) + -? --help Display help message + -V --version Print version information + +Examples +-------- + +Search for entries matching a sequence: + + $ sloane 1,3,19,183,2371,38703 + + S A006531 1,1,3,19,183,2371,38703,763099,17648823,468603091,14050842303, + N A006531 Semiorders on n elements. + +Show the sequence, name, formula and comments fields of the sequence whose A-number is A006531: + + $ sloane -kSNFC id:A006531 + + S A006531 1,1,3,19,183,2371,38703,763099,17648823,468603091,14050842303, + N A006531 Semiorders on n elements. + F A006531 O.g.f.: Sum_{n>=1} (2*n)!/(n+1)! * x^n / Product_{k=0..n} (1+k*x). [From Paul D. Hanna, Jul 20 2011] + F A006531 E.g.f.: C(1-exp(-x)), where C(x) = (1 - sqrt(1 - 4*x)) / (2*x) is the ordinary g.f. for the Catalan numbers A000108. + F A006531 a(n) = sum( S(n, k) * k! * M(k-1), k=1..n), S(n, k): Stirling number of the second kind, M(n): Motzkin number, A001006. - Detlef Pauly, Jun 06 2002 + C A006531 Labeled semiorders on n elements: (1+3) and (2+2)-free posets. - Detlef Pauly (dettodet(AT)yahoo.de), Dec 27 2002 + +Return at most 3 results of a free text search: + + $ sloane -n3 "(2+2)-free posets" + + S A079144 1,1,3,19,207,3451,81663,2602699,107477247,5581680571,356046745023, + N A079144 Number of labeled interval orders on n elements: (2+2)-free posets. + + S A022493 1,1,2,5,15,53,217,1014,5335,31240,201608,1422074,10886503,89903100, + N A022493 Number of linearized chord diagrams of degree n; also number of nonisomorphic interval orders on n unlabeled points. + + S A006531 1,1,3,19,183,2371,38703,763099,17648823,468603091,14050842303, + N A006531 Semiorders on n elements. + +Caveat +------ + +Please use this program with moderation as not to put too much of a burden on the OEIS-server; see +[OEIS' policy on searching the database](http://oeis.org/wiki/Welcome#Policy_on_Searching_the_Database). diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,2 @@ +import Distribution.Simple +main = defaultMain diff --git a/sloane.cabal b/sloane.cabal new file mode 100644 --- /dev/null +++ b/sloane.cabal @@ -0,0 +1,23 @@ +Name: sloane +Version: 0.1 +Synopsis: A command line interface to Sloane's On-Line Encyclopedia of Integer Sequences +Description: A command line interface to Sloane's On-Line Encyclopedia of Integer Sequences. + For usage see . +Homepage: http://github.com/akc/sloane +License: BSD3 +License-file: LICENSE +Author: Anders Claesson +Maintainer: anders.claesson@gmail.com +Category: Math +Build-type: Simple +Extra-Source-Files: README.md + +Cabal-version: >=1.6 + +source-repository head + type: git + location: git://github.com/akc/sloane.git + +Executable sloane + Main-is: sloane.hs + Build-depends: base >= 3 && < 5, cmdargs, HTTP, url diff --git a/sloane.hs b/sloane.hs new file mode 100644 --- /dev/null +++ b/sloane.hs @@ -0,0 +1,89 @@ +{-# LANGUAGE DeriveDataTypeable #-} + +import Prelude hiding (all) +import System.Console.CmdArgs +import Data.Maybe (fromJust, isJust) +import Data.Function (on) +import Data.IORef (IORef, newIORef, readIORef, writeIORef) +import Control.Monad (when) +import System.IO.Unsafe (unsafePerformIO) +import Network.HTTP (simpleHTTP, getRequest, getResponseBody) +import Network.URL (importURL, exportURL, add_param) +import Data.List (groupBy, sortBy, intersperse) +import Data.Ord (comparing) + +newtype OEISEntry = OEISEntry [(Char, String)] + +oeisURL = fromJust $ importURL "http://oeis.org/search?fmt=text" +oeisKeys = "ISTUVWXNDHFYAOEeptoKC" + +data Sloane = Sloane { keys :: String + , all :: Bool + , limit :: Int + , terms :: String + } + deriving (Data, Typeable) + +sloane = cmdArgsMode $ Sloane + { keys = "SN" &= typ "KEYS" + &= help "Keys of fields to print, http://oeis.org/eishelp1.html (default: SN)" + , all = False + &= help "Print all fields" + , limit = 5 &= name "n" + &= help "Limit the number of entries retrieved (default: 5)" + , terms = def &= argPos 0 &= typ "SEARCH-TERMS" + } + &= versionArg [summary "sloane 0.1"] + &= summary "Search Sloane's On-Line Encyclopedia of Integer Sequences" + +-- The maximum number of results returned when searching the OEIS. +maxResults :: IORef Int +maxResults = unsafePerformIO $ newIORef 5 + +-- Get the maximum number of results returned when searching OEIS +getMaxResults :: IO Int +getMaxResults = readIORef maxResults + +-- Set the maximum number of results returned when searching OEIS +setMaxResults :: Int -> IO () +setMaxResults = writeIORef maxResults + +nonempty = not . null + +parseOEISEntry :: String -> OEISEntry +parseOEISEntry = OEISEntry + . map merge + . groupBy ((==) `on` fst) + . sortBy (comparing fst) + . map (split . tail) . filter nonempty . lines + where + split xs@(x:_) = (x, xs) + merge kvs = let (k:_, vs) = unzip kvs in (k, init $ unlines vs) + +parseOEISEntries :: String -> [OEISEntry] +parseOEISEntries = map parseOEISEntry + . filter nonempty + . map unlines + . groupBy (\_ x -> nonempty x) + . reverse . drop 2 . reverse . drop 5 . lines + +-- Returns the given fields of an 'OEISEntry'. For instance, @fields "NFA" e@ +-- would return the name, formula, and auhtor fields of @e@. +fields :: String -> OEISEntry -> [String] +fields ks (OEISEntry e) = [ fromJust d | k<-ks, let d = lookup k e, isJust d ] + +-- Returns a list of matching entries in OEIS +lookupOEIS :: String -> IO [OEISEntry] +lookupOEIS s = do + n <- getMaxResults + parseOEISEntries `fmap` (simpleHTTP (getRequest (url n)) >>= getResponseBody) + where + url n = exportURL $ oeisURL `add_param` ("n", show n) `add_param` ("q", s) + +main = do + args <- cmdArgsRun sloane + setMaxResults $ limit args + es <- lookupOEIS . filter (`notElem` "[]") $ terms args + when (nonempty es) $ putStrLn "" + let ks = if all args then oeisKeys else keys args + mapM_ putStrLn [ unlines $ fields ks e | e <- es ]