From 3f4bbe9b9e02d0e7f424d6fabfe7e40ea7c9b205 Mon Sep 17 00:00:00 2001
From: Paulo Moura <>
Date: Sat, 8 May 2021 21:23:54 +0100
Subject: [PATCH] Add epsilon/0 arithmetic constant

---
 src/arithmetic.rs             | 6 ++++++
 src/machine/arithmetic_ops.rs | 3 +++
 2 files changed, 9 insertions(+)

diff --git a/src/arithmetic.rs b/src/arithmetic.rs
index 87e72d45..f5a3beeb 100644
--- a/src/arithmetic.rs
+++ b/src/arithmetic.rs
@@ -290,6 +290,12 @@ impl<'a> ArithmeticEvaluator<'a> {
                         f64::consts::PI,
                     ))))
             }
+            &Constant::Atom(ref name, _) if name.as_str() == "epsilon" => {
+                self.interm
+                    .push(ArithmeticTerm::Number(Number::Float(OrderedFloat(
+                        f64::EPSILON,
+                    ))))
+            }
             _ => return Err(ArithmeticError::NonEvaluableFunctor(c.clone(), 0)),
         }
 
diff --git a/src/machine/arithmetic_ops.rs b/src/machine/arithmetic_ops.rs
index 9ce4eac0..dc06fd5a 100644
--- a/src/machine/arithmetic_ops.rs
+++ b/src/machine/arithmetic_ops.rs
@@ -227,6 +227,9 @@ impl MachineState {
                 &HeapCellValue::Atom(ref name, _) if name.as_str() == "e" => {
                     interms.push(Number::Float(OrderedFloat(f64::consts::E)))
                 }
+                &HeapCellValue::Atom(ref name, _) if name.as_str() == "epsilon" => {
+                    interms.push(Number::Float(OrderedFloat(f64::EPSILON)))
+                }
                 &HeapCellValue::NamedStr(arity, ref name, _) => {
                     let evaluable_stub = MachineError::functor_stub(name.clone(), arity);
 
-- 
2.54.0