From dece879b279cbae6440aaf898a9f051ee11d9912 Mon Sep 17 00:00:00 2001
From: Stefan Ellmauthaler <stefan.ellmauthaler@tu-dresden.de>
Date: Tue, 21 Jun 2022 16:10:26 +0200
Subject: [PATCH] Add missing heuristics module to git

---
 lib/src/adf/heuristics.rs | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 lib/src/adf/heuristics.rs

diff --git a/lib/src/adf/heuristics.rs b/lib/src/adf/heuristics.rs
new file mode 100644
index 0000000..301dc3d
--- /dev/null
+++ b/lib/src/adf/heuristics.rs
@@ -0,0 +1,34 @@
+/*!
+This module contains all the crate-wide defined heuristic functions.
+In addition there is the public enum [Heuristic], which allows to set a heuristic function with the public API.
+ */
+use super::Adf;
+use crate::datatypes::{Term, Var};
+
+pub(crate) fn heu_simple(_adf: &Adf, interpr: &[Term]) -> Option<(Var, Term)> {
+    for (idx, term) in interpr.iter().enumerate() {
+        if !term.is_truth_value() {
+            return Some((Var(idx), Term::TOP));
+        }
+    }
+    None
+}
+
+type RetVal = Option<(Var, Term)>;
+
+/// Enumeration of all currently implemented heuristics.
+/// It represents a public view on the crate-view implementations of heuristics.
+#[derive(Debug, Clone, Copy)]
+pub enum Heuristic {
+    /// Implementation of a simple heuristic.
+    /// This will just take the first not decided variable and maps it value to (`true`)[Term::TOP].   
+    Simple,
+}
+
+impl Heuristic {
+    pub(crate) fn get_heuristic(&self) -> Box<dyn Fn(&Adf, &[Term]) -> RetVal> {
+        match self {
+            Heuristic::Simple => Box::new(heu_simple),
+        }
+    }
+}