Add functor concept.

1 files changed, 14 insertions, 0 deletions

diff --git a/data/functor.scm b/data/functor.scm
new file mode 100644
index 0000000..2286337
--- /dev/null
+++ b/data/functor.scm
@@ -0,0 +1,14 @@
+(define-module (data functor)
+  #:use-module (oop goops)
+  #:use-module (srfi srfi-1)
+  #:export (fmap <$>))
+
+;;; We don't overwrite the default map since that creates way to many
+;;; namespace problems.
+
+(define-generic fmap)
+(define <$> fmap)
+
+;;; Default fallback for fmap is regular (srfi-1) map.
+(define-method (fmap f . lists)
+  (apply map f lists))