1 files changed, 67 insertions, 0 deletions
diff --git a/stdlib/source/library/lux/world/finance/trade/session.lux b/stdlib/source/library/lux/world/finance/trade/session.lux
new file mode 100644
index 000000000..821135300
--- /dev/null
+++ b/stdlib/source/library/lux/world/finance/trade/session.lux
@@ -0,0 +1,67 @@
+(.require
+ [library
+  [lux (.except)
+   [abstract
+    [equivalence (.only Equivalence)]]
+   [data
+    [text
+     ["%" \\format (.only Format)]]]
+   [math
+    [number
+     ["n" nat]]]]]
+ [///
+  ["[0]" money (.only Money)
+   [currency (.only Currency)]]])
+
+(type .public (Price $)
+  (Money $))
+
+(type .public Volume
+  Nat)
+
+(type .public (Session $)
+  (Record
+   [#open (Price $)
+    #high (Price $)
+    #low (Price $)
+    #close (Price $)
+    #volume Volume]))
+
+(def .public equivalence
+  (All (_ $)
+    (Equivalence (Session $)))
+  (implementation
+   (def (= reference subject)
+     (`` (and (,, (with_template [<=> <slot>]
+                    [(<=> (the <slot> reference) (the <slot> subject))]
+
+                    [money.= #open]
+                    [money.= #high]
+                    [money.= #low]
+                    [money.= #close]
+                    [n.= #volume]
+                    )))))))
+
+(def .public (composite before after)
+  (All (_ $)
+    (-> (Session $) (Session $)
+        (Session $)))
+  [#open (the #open before)
+   #high (money.max (the #high before) (the #high after))
+   #low (money.min (the #low before) (the #low after))
+   #close (the #close after)
+   #volume (n.+ (the #volume before) (the #volume after))])
+
+... https://en.wikipedia.org/wiki/Open-high-low-close_chart
+(def .public (format it)
+  (All (_ $)
+    (Format (Session $)))
+  (`` (%.format (,, (with_template [<header> <slot> <format>]
+                      [<header> ": " (`` (<format> (the <slot> it)))]
+
+                      ["O" #open money.format]
+                      [" | H" #high money.format]
+                      [" | L" #low money.format]
+                      [" | C" #close money.format]
+                      [" | V" #volume %.nat]
+                      )))))