1 files changed, 68 insertions, 0 deletions
diff --git a/Data/Libraries/Penlight/tests/test-list.lua b/Data/Libraries/Penlight/tests/test-list.lua
new file mode 100644
index 0000000..4e290d6
--- /dev/null
+++ b/Data/Libraries/Penlight/tests/test-list.lua
@@ -0,0 +1,68 @@
+local List = require 'pl.List'
+local class = require 'pl.class'
+local test = require 'pl.test'
+local asserteq, T = test.asserteq, test.tuple
+
+-- note that a _plain table_ is made directly into a list
+local t = {10,20,30}
+local ls = List(t)
+asserteq(t,ls)
+
+asserteq(List({}):reverse(), {})
+asserteq(List({1}):reverse(), {1})
+asserteq(List({1,2}):reverse(), {2,1})
+asserteq(List({1,2,3}):reverse(), {3,2,1})
+asserteq(List({1,2,3,4}):reverse(), {4,3,2,1})
+
+-- you may derive classes from pl.List, and the result is covariant.
+-- That is, slice() etc will return a list of the derived type, not List.
+
+local NA = class(List)
+
+local function mapm(a1,op,a2)
+  local M = type(a2)=='table' and List.map2 or List.map
+  return M(a1,op,a2)
+end
+
+--- elementwise arithmetric operations
+function NA.__unm(a) return a:map '|X|-X' end
+function NA.__pow(a,s) return a:map '|X,Y|X^Y' end
+function NA.__add(a1,a2) return mapm(a1,'|X,Y|X+Y',a2) end
+function NA.__sub(a1,a2) return mapm(a1,'|X,Y|X-Y',a2) end
+function NA.__div(a1,a2) return mapm(a1,'|X,Y|X/Y',a2) end
+function NA.__mul(a1,a2) return mapm(a2,'|X,Y|X*Y',a1) end
+
+function NA:minmax ()
+    local min,max = math.huge,-math.huge
+    for i = 1,#self do
+        local val = self[i]
+        if val > max then max = val end
+        if val < min then min = val end
+    end
+    return min,max
+end
+
+function NA:sum ()
+    local res = 0
+    for i = 1,#self do
+        res = res + self[i]
+    end
+    return res
+end
+
+function NA:normalize ()
+    return self:transform('|X,Y|X/Y',self:sum())
+end
+
+n1 = NA{10,20,30}
+n2 = NA{1,2,3}
+ns = n1 + 2*n2
+
+asserteq(List:class_of(ns),true)
+asserteq(NA:class_of(ns),true)
+asserteq(ns:is_a(NA),true)
+asserteq(ns,{12,24,36})
+min,max = ns:slice(1,2):minmax()
+asserteq(T(min,max),T(12,24))
+
+asserteq(n1:normalize():sum(),1,1e-8)