[bug#28884] [PATCH 32/38] gnu: Add ghc-vector-builder.

[rsiddharth]

* gnu/packages/haskell.scm (ghc-vector-builder): New variable.
---
 gnu/packages/haskell.scm | 57 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/gnu/packages/haskell.scm b/gnu/packages/haskell.scm
index 129f1792e..682f2da1e 100644
--- a/gnu/packages/haskell.scm
+++ b/gnu/packages/haskell.scm
@@ -9981,4 +9981,61 @@ The package is intended to rapidly evolve with the 
contribution from
 the community, with the missing features being added with pull-requests.")
     (license license:expat)))
 
+(define-public ghc-vector-builder
+  (package
+    (name "ghc-vector-builder")
+    (version "0.3.1")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (string-append "https://hackage.haskell.org/package/";
+                           "vector-builder-" version "/"
+                           "vector-builder-" version ".tar.gz"))
+       (sha256
+        (base32
+         "1l6sfgd2s107zkp1qd1w6jdjcbznp31769qf99pxar087f697wvp"))))
+    (build-system haskell-build-system)
+    (inputs `(("ghc-vector" ,ghc-vector)
+              ("ghc-semigroups" ,ghc-semigroups)
+              ("ghc-base-prelude" ,ghc-base-prelude)))
+    (native-inputs `(("ghc-tasty" ,ghc-tasty)
+                     ("ghc-tasty-hunit" ,ghc-tasty-hunit)
+                     ("ghc-tasty-quickcheck" ,ghc-tasty-quickcheck)
+                     ("ghc-hunit" ,ghc-hunit)
+                     ("ghc-quickcheck-instances" ,ghc-quickcheck-instances)
+                     ("ghc-rebase" ,ghc-rebase)))
+    (home-page "https://github.com/nikita-volkov/vector-builder";)
+    (synopsis "Vector builder for Haskell")
+    (description "This Haskell package provides an API for constructing 
vectors.
+
+It provides the composable @code{Builder} abstraction, which has instances of 
the
address@hidden and @code{Semigroup} classes.
+
+Usage:
+
+First you use the @code{Builder} abstraction to specify the structure of the
+vector.  Then you execute the builder to actually produce the vector.
+
+Example:
+
+The following code shows how you can efficiently concatenate different
+datastructures into a single immutable vector:
+
address@hidden
+import qualified Data.Vector as A
+import qualified VectorBuilder.Builder as B
+import qualified VectorBuilder.Vector as C
+
+myVector :: A.Vector a -> [a] -> a -> A.Vector a
+myVector vector list element =
+ C.build builder
+  where
+    builder =
+      B.vector vector <>
+      foldMap B.singleton list <>
+      B.singleton element
address@hidden verbatim
+")
+    (license license:expat)))
+
 ;;; haskell.scm ends here
-- 
2.15.0.rc0