lang: funcs: core: Make module names public

This is needed for when we have nested modules.

lang/funcs/core/datetime/datetime.go

@@ -18,6 +18,6 @@
 package coredatetime
 
 const (
-	// moduleName is the prefix given to all the functions in this module.
-	moduleName = "datetime"
+	// ModuleName is the prefix given to all the functions in this module.
+	ModuleName = "datetime"
 )

lang/funcs/core/datetime/now_fact.go

@@ -25,7 +25,7 @@ import (
 )
 
 func init() {
-	facts.ModuleRegister(moduleName, "now", func() facts.Fact { return &DateTimeFact{} }) // must register the fact and name
+	facts.ModuleRegister(ModuleName, "now", func() facts.Fact { return &DateTimeFact{} }) // must register the fact and name
 }
 
 // DateTimeFact is a fact which returns the current date and time.

lang/funcs/core/datetime/print_func.go

@@ -27,7 +27,7 @@ import (
 
 func init() {
 	// FIXME: consider renaming this to printf, and add in a format string?
-	simple.ModuleRegister(moduleName, "print", &types.FuncValue{
+	simple.ModuleRegister(ModuleName, "print", &types.FuncValue{
 		T: types.NewType("func(a int) str"),
 		V: func(input []types.Value) (types.Value, error) {
 			epochDelta := input[0].Int()

lang/funcs/core/datetime/weekday_func.go

@@ -27,7 +27,7 @@ import (
 )
 
 func init() {
-	simple.ModuleRegister(moduleName, "weekday", &types.FuncValue{
+	simple.ModuleRegister(ModuleName, "weekday", &types.FuncValue{
 		T: types.NewType("func(a int) str"),
 		V: Weekday,
 	})