move apis into rom/modules/main for shell compatibility

sys/modules/opus/map.lua

@@ -0,0 +1,51 @@
+-- convience functions for tables with key/value pairs
+local Util = require('opus.util')
+
+local Map = { }
+
+-- TODO: refactor
+Map.merge = Util.merge
+Map.shallowCopy = Util.shallowCopy
+Map.find = Util.find
+Map.filter = Util.filter
+
+function Map.removeMatches(t, values)
+	local function matchAll(entry)
+		for k, v in pairs(values) do
+			if entry[k] ~= v then
+				return
+			end
+		end
+		return true
+	end
+
+	for _, key in pairs(Util.keys(t)) do
+		if matchAll(t[key]) then
+			t[key] = nil
+		end
+	end
+end
+
+-- remove table entries if passed function returns false
+function Map.prune(t, fn)
+	for _,k in pairs(Util.keys(t)) do
+		local v = t[k]
+		if type(v) == 'table' then
+			t[k] = Map.prune(v, fn)
+		end
+		if not fn(t[k]) then
+			t[k] = nil
+		end
+	end
+	return t
+end
+
+function Map.size(list)
+	local length = 0
+	for _ in pairs(list) do
+		length = length + 1
+	end
+	return length
+end
+
+return Map