Very wastefully computes the eleven sets of gifts

app/Main.hs

@@ -0,0 +1,104 @@
+module Main (main) where
+
+ordinals :: [ String ]
+ordinals = [
+    "first",
+    "second",
+    "third",
+    "fourth",
+    "fifth",
+    "sixth",
+    "seventh",
+    "eighth",
+    "ninth",
+    "tenth",
+    "eleventh",
+    "twelfth"
+    ]
+
+
+cardinals :: [ String ]
+cardinals = [
+    "two",
+    "three",
+    "four",
+    "five",
+    "six",
+    "seven",
+    "eight",
+    "nine",
+    "ten",
+    "eleven",
+    "twelve"
+    ]
+
+
+gifta :: [ String ]
+gifta = [
+    "turtle",
+    "French",
+    "calling",
+    "gold",
+    "geese",
+    "swans",
+    "maids",
+    "ladies",
+    "lords",
+    "pipers",
+    "drummers"
+    ]
+
+giftb :: [ String ]
+giftb = [
+    "doves",
+    "hens",
+    "birds",
+    "rings",
+    "a-laying",
+    "a-swimming",
+    "a-milking",
+    "dancing",
+    "a-leaping",
+    "piping",
+    "drumming"
+    ]
+
+signatures :: [ ( Int, Int, Int, Int) ]
+signatures = [
+    ( 3, 6, 5, 0 ),
+    ( 5, 6, 4, 1 ),
+    ( 4, 7, 5, 1 ),
+    ( 4, 4, 5, 5 ),
+    ( 3, 5, 8, 8 ),
+    ( 5, 5, 10, 5 ),
+    ( 5, 5, 9, 20 ),
+    ( 4, 6, 7, 10 ),
+    ( 3, 5, 9, 23 ),
+    ( 6, 6, 6, 3 ),
+    ( 6, 8, 8, 3 )
+    ]
+
+gifts :: [ ( String, String, String ) ]
+gifts = [ ( c, a, b ) | c <- cardinals, a <- gifta, b <- giftb ]
+
+matchGifts :: ( Int, Int, Int ) -> [ ( String, String, String ) ]
+matchGifts ( i, j, k ) = filter match gifts
+    where
+        match ( c, a, b ) = (length c == i) && (length a == j) && (length b == k)
+
+giftStr :: ( String, String, String ) -> String
+giftStr (c, a, b) = c ++ " " ++ a ++ " " ++ b
+
+wrapGift :: ( Int, Int, Int, Int ) -> String
+wrapGift (i, j, k, l) = gs !! l
+    where
+        gs = map giftStr $ matchGifts (i, j, k)
+
+wrapGifts :: String
+wrapGifts = foldr (\a b -> a ++ "\n" ++ b) "" gs
+    where
+        gs = map wrapGift signatures
+
+
+main :: IO ()
+main = putStrLn wrapGifts

stack.yaml

@@ -0,0 +1,67 @@
+# This file was automatically generated by 'stack init'
+#
+# Some commonly used options have been documented as comments in this file.
+# For advanced use and comprehensive documentation of the format, please see:
+# https://docs.haskellstack.org/en/stable/configure/yaml/
+
+# A 'specific' Stackage snapshot or a compiler version.
+# A snapshot resolver dictates the compiler version and the set of packages
+# to be used for project dependencies. For example:
+#
+# snapshot: lts-23.24
+# snapshot: nightly-2025-06-15
+# snapshot: ghc-9.8.4
+#
+# The location of a snapshot can be provided as a file or url. Stack assumes
+# a snapshot provided as a file might change, whereas a url resource does not.
+#
+# snapshot: ./custom-snapshot.yaml
+# snapshot: https://example.com/snapshots/2024-01-01.yaml
+snapshot:
+  url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/24/25.yaml
+
+# User packages to be built.
+# Various formats can be used as shown in the example below.
+#
+# packages:
+# - some-directory
+# - https://example.com/foo/bar/baz-0.0.2.tar.gz
+#   subdirs:
+#   - auto-update
+#   - wai
+packages:
+- .
+# Dependency packages to be pulled from upstream that are not in the snapshot.
+# These entries can reference officially published versions as well as
+# forks / in-progress versions pinned to a git hash. For example:
+#
+# extra-deps:
+# - acme-missiles-0.3
+# - git: https://github.com/commercialhaskell/stack.git
+#   commit: e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+#
+# extra-deps: [ ]
+
+# Override default flag values for project packages and extra-deps
+# flags: {}
+
+# Extra package databases containing global packages
+# extra-package-dbs: []
+
+# Control whether we use the GHC we find on the path
+# system-ghc: true
+#
+# Require a specific version of Stack, using version ranges
+# require-stack-version: -any # Default
+# require-stack-version: ">=3.7"
+#
+# Override the architecture used by Stack, especially useful on Windows
+# arch: i386
+# arch: x86_64
+#
+# Extra directories used by Stack for building
+# extra-include-dirs: [/path/to/dir]
+# extra-lib-dirs: [/path/to/dir]
+#
+# Allow a newer minor version of GHC than the snapshot specifies
+# compiler-check: newer-minor

xmasTwelve.cabal

@@ -0,0 +1,67 @@
+cabal-version: 2.2
+
+-- This file has been generated from package.yaml by hpack version 0.38.1.
+--
+-- see: https://github.com/sol/hpack
+
+name:           xmasTwelve
+version:        0.1.0.0
+description:    Please see the README on GitHub at <https://github.com/githubuser/xmasTwelve#readme>
+homepage:       https://github.com/githubuser/xmasTwelve#readme
+bug-reports:    https://github.com/githubuser/xmasTwelve/issues
+author:         Author name here
+maintainer:     example@example.com
+copyright:      2025 Author name here
+license:        BSD-3-Clause
+license-file:   LICENSE
+build-type:     Simple
+extra-source-files:
+    README.md
+    CHANGELOG.md
+
+source-repository head
+  type: git
+  location: https://github.com/githubuser/xmasTwelve
+
+library
+  exposed-modules:
+      Lib
+  other-modules:
+      Paths_xmasTwelve
+  autogen-modules:
+      Paths_xmasTwelve
+  hs-source-dirs:
+      src
+  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints
+  build-depends:
+      base >=4.7 && <5
+  default-language: Haskell2010
+
+executable xmasTwelve-exe
+  main-is: Main.hs
+  other-modules:
+      Paths_xmasTwelve
+  autogen-modules:
+      Paths_xmasTwelve
+  hs-source-dirs:
+      app
+  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints -threaded -rtsopts -with-rtsopts=-N
+  build-depends:
+      base >=4.7 && <5
+    , xmasTwelve
+  default-language: Haskell2010
+
+test-suite xmasTwelve-test
+  type: exitcode-stdio-1.0
+  main-is: Spec.hs
+  other-modules:
+      Paths_xmasTwelve
+  autogen-modules:
+      Paths_xmasTwelve
+  hs-source-dirs:
+      test
+  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints -threaded -rtsopts -with-rtsopts=-N
+  build-depends:
+      base >=4.7 && <5
+    , xmasTwelve
+  default-language: Haskell2010