Switch to oeis2 library and reinstate OEIS support (#427)

Closes #367.

disco.cabal

@@ -499,7 +499,7 @@ library
                        splitmix >= 0.1 && < 0.2,
                        fgl >= 5.5 && < 5.9,
                        optparse-applicative >= 0.12 && < 0.19,
-                       -- oeis2 < 1.1,
+                       oeis2 >= 1.0.9 && < 1.1,
                        algebraic-graphs >= 0.5 && < 0.8,
                        pretty-show >= 1.10 && < 1.11,
                        boxes >= 0.1.5 && < 0.2,
@@ -525,8 +525,8 @@ executable disco
                        containers >= 0.5 && < 0.8,
                        unbound-generics >= 0.3 && < 0.5,
                        lens >= 4.14 && < 5.4,
-                       optparse-applicative >= 0.12 && < 0.19
-                       -- oeis2 < 1.1
+                       optparse-applicative >= 0.12 && < 0.19,
+                       oeis2 >= 1.0.9 && < 1.1
 
   default-language:    Haskell2010
 

docs/reference/library.rst

@@ -13,3 +13,4 @@ then go through each of the available standard libraries.
    prop-lib
    string-lib
    prim-lib
+   oeis-lib

docs/reference/oeis-lib.rst

@@ -0,0 +1,37 @@
+oeis
+====
+
+Disco provides a library for interfacing with the `Online Encyclopedia
+of Integer Sequences <OEIS_>`_ (OEIS).  You can :doc:`import
+<import>` it with:
+
+.. _OEIS: https://oeis.org/
+
+::
+
+   import oeis
+
+The library provides two functions:
+
+* The ``lookupSequence`` function takes a list of natural numbers and
+  returns the URL of the first result in the OEIS.  For example:
+
+  ::
+
+     Disco> lookupSequence [1,1,2,3,5,8]
+     right("https://oeis.org/A000045")
+
+  In this example, the returned URL is in fact the OEIS page for the
+  `Fibonacci numbers <fib_>`_.
+
+* The ``extendSequence`` function tries to *extend* the given list as
+  far as it can, using data from the first match on the OEIS.  Using
+  the same example as before, just by putting in the first few
+  Fibonacci numbers we can get a lot more:
+
+  ::
+
+     Disco> extendSequence [1,1,2,3,5,8]
+     [1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181, 6765, 10946, 17711, 28657, 46368, 75025, 121393, 196418, 317811, 514229, 832040, 1346269, 2178309, 3524578, 5702887, 9227465, 14930352, 24157817, 39088169, 63245986, 102334155]
+
+.. _fib: https://oeis.org/A000045

src/Disco/Interpret/CESK.hs

@@ -32,6 +32,7 @@ import qualified Data.List.Infinite as InfList
 import qualified Data.Map as M
 import Data.Maybe (isJust)
 import Data.Ratio
+import qualified Data.Text as T
 import Disco.AST.Core
 import Disco.AST.Generic (
   Ellipsis (..),
@@ -41,6 +42,8 @@ import Disco.AST.Generic (
 import Disco.AST.Typed (AProperty)
 import Disco.Compile
 import Disco.Context as Ctx
+import Disco.Effects.Fresh
+import Disco.Effects.Input
 import Disco.Enumerate
 import Disco.Error
 import Disco.Names
@@ -51,15 +54,12 @@ import Math.Combinatorics.Exact.Binomial (choose)
 import Math.Combinatorics.Exact.Factorial (factorial)
 import Math.NumberTheory.Primes (factorise, unPrime)
 import Math.NumberTheory.Primes.Testing (isPrime)
-
--- import Math.OEIS (
---   catalogNums,
---   extendSequence,
---   lookupSequence,
---  )
-
-import Disco.Effects.Fresh
-import Disco.Effects.Input
+import Math.OEIS (
+  SearchStatus (SubSeq),
+  extendSeq,
+  lookupSeq,
+  number,
+ )
 import Polysemy
 import Polysemy.Error
 import Polysemy.Random
@@ -356,8 +356,8 @@ appConst k = \case
   -- Sequences
 
   OUntil -> arity2 $ \v1 -> out . ellipsis (Until v1)
-  -- OLookupSeq -> out . oeisLookup
-  -- OExtendSeq -> out . oeisExtend
+  OLookupSeq -> out . oeisLookup
+  OExtendSeq -> out . oeisExtend
   --------------------------------------------------
   -- Comparison
 
@@ -639,23 +639,19 @@ constdiff (x : xs)
 -- OEIS
 ------------------------------------------------------------
 
--- -- | Looks up a sequence of integers in OEIS.
--- --   Returns 'left()' if the sequence is unknown in OEIS,
--- --   otherwise 'right "https://oeis.org/<oeis_sequence_id>"'
--- oeisLookup :: Value -> Value
--- oeisLookup (vlist vint -> ns) = maybe VNil parseResult (lookupSequence ns)
---  where
---   parseResult r = VInj R (listv charv ("https://oeis.org/" ++ seqNum r))
---   seqNum = getCatalogNum . catalogNums
-
---   getCatalogNum [] = error "No catalog info"
---   getCatalogNum (n : _) = n
-
--- -- | Extends a Disco integer list with data from a known OEIS
--- --   sequence.  Returns a list of integers upon success, otherwise the
--- --   original list (unmodified).
--- oeisExtend :: Value -> Value
--- oeisExtend = listv intv . extendSequence . vlist vint
+-- | Looks up a sequence of integers in OEIS.
+--   Returns 'left()' if the sequence is unknown in OEIS,
+--   otherwise 'right "https://oeis.org/<oeis_sequence_id>"'
+oeisLookup :: Value -> Value
+oeisLookup (vlist vint -> ns) = maybe VNil parseResult (lookupSeq (SubSeq ns))
+ where
+  parseResult r = VInj R (listv charv ("https://oeis.org/" ++ T.unpack (number r)))
+
+-- | Extends a Disco integer list with data from a known OEIS
+--   sequence.  Returns a list of integers upon success, otherwise the
+--   original list (unmodified).
+oeisExtend :: Value -> Value
+oeisExtend = listv intv . extendSeq . vlist vint
 
 ------------------------------------------------------------
 -- Normalizing bags/sets

stack.yaml

@@ -13,8 +13,7 @@ extra-deps:
   - unbound-generics-0.4.4
   - ansi-wl-pprint-0.6.9
   - simple-enumeration-0.2.1@sha256:8625b269c1650d3dd0e3887351c153049f4369853e0d525219e07480ea004b9f,1178
-    # - HTTP-4000.3.16@sha256:6042643c15a0b43e522a6693f1e322f05000d519543a84149cb80aeffee34f71,5947
-    # HTTP-4000.3 needed for oeis-0.3.10
+  - oeis2-1.0.9
 
 # Override default flag values for local packages and extra-deps
 flags: {}