From d4ea952032b099a4674c27e964ab6ec421c690f4 Mon Sep 17 00:00:00 2001
From: Nathanael Sensfelder <SpamShield0@MultiAgentSystems.org>
Date: Fri, 26 Apr 2019 23:21:22 +0200
Subject: Dubious way to have lazy orddict updates.

I want to keep the benefits of orddict:fetch vs orddict:find, but still
be able to re-use the existing code when adding a new element.
---
 src/ataxic.erl       |  6 +++++-
 src/ataxic_sugar.erl | 32 +++++++++++++++++++-------------
 2 files changed, 24 insertions(+), 14 deletions(-)

(limited to 'src')

diff --git a/src/ataxic.erl b/src/ataxic.erl
index 195d77f..4d829f3 100644
--- a/src/ataxic.erl
+++ b/src/ataxic.erl
@@ -126,7 +126,7 @@
 
 -export([apply_to/2, matches/2]).
 
--export([optimize/1]).
+-export([optimize/1, is_constant/1]).
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% LOCAL FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -378,3 +378,7 @@ matches (OP, Entry) ->
       true -> true;
       _ -> false
    end.
+
+-spec is_constant (basic()) -> boolean().
+is_constant (#const{}) -> true;
+is_constant(_) -> false.
diff --git a/src/ataxic_sugar.erl b/src/ataxic_sugar.erl
index 3098196..7f6e441 100644
--- a/src/ataxic_sugar.erl
+++ b/src/ataxic_sugar.erl
@@ -64,20 +64,26 @@ update_orddict_element (IX, OP) ->
       store,
       [
          ataxic:constant(IX),
-         ataxic:sequence
          (
-            [
-               ataxic:apply_function
-               (
-                  orddict,
-                  fetch,
-                  [
-                     ataxic:constant(IX),
-                     ataxic:current_value()
-                  ]
-               ),
-               OP
-            ]
+            case ataxic:is_constant(OP) of
+               true -> OP;
+               false ->
+                  ataxic:sequence
+                  (
+                     [
+                        ataxic:apply_function
+                        (
+                           orddict,
+                           fetch,
+                           [
+                              ataxic:constant(IX),
+                              ataxic:current_value()
+                           ]
+                        ),
+                        OP
+                     ]
+                  )
+            end
          ),
          ataxic:current_value()
       ]
-- 
cgit v1.2.3-70-g09d2