From 631aae8d8807b9ce04ec7693bb1d2ba531d215f8 Mon Sep 17 00:00:00 2001
From: Paulo Moura <pmoura@logtalk.org>
Date: Fri, 10 Sep 2021 22:36:05 +0100
Subject: [PATCH] Add de facto standard hyperbolic arithmetic functions

---
 docs/index_status.html                 |  6 ++++++
 src/docs/content.index_status.template |  6 ++++++
 src/engine/foreign.js                  | 22 ++++++++++++++++++++++
 3 files changed, 34 insertions(+)

diff --git a/docs/index_status.html b/docs/index_status.html
index 8e7bbbf..02d2a01 100644
--- a/docs/index_status.html
+++ b/docs/index_status.html
@@ -695,6 +695,12 @@ <h2>9.3 Other arithmetic functors</h2>
                 <li>acos/1.</li>
                 <li>atan2/2.</li>
                 <li>tan/1.</li>
+                <li>acosh/1.</li>
+                <li>asinh/1.</li>
+                <li>atanh/1.</li>
+                <li>cosh/1.</li>
+                <li>sinh/1.</li>
+                <li>tanh/1.</li>
                 <li>pi/0.</li>
             </ol>
         </div>
diff --git a/src/docs/content.index_status.template b/src/docs/content.index_status.template
index 17ed954..58dac20 100644
--- a/src/docs/content.index_status.template
+++ b/src/docs/content.index_status.template
@@ -334,6 +334,12 @@ The ProscriptLS aspiration includes implementing most of ISO Prolog and some add
                 <li>acos/1.</li>
                 <li>atan2/2.</li>
                 <li>tan/1.</li>
+                <li>acosh/1.</li>
+                <li>asinh/1.</li>
+                <li>atanh/1.</li>
+                <li>cosh/1.</li>
+                <li>sinh/1.</li>
+                <li>tanh/1.</li>
                 <li>pi/0.</li>
             </ol>
         </div>
diff --git a/src/engine/foreign.js b/src/engine/foreign.js
index 5b206c2..b4d5091 100644
--- a/src/engine/foreign.js
+++ b/src/engine/foreign.js
@@ -164,6 +164,28 @@ function evaluate_expression(expression, evaluated)
                 return evaluation_error("zero_divisor");
             evaluated.value = round(v[0] /v[1]);        
         }
+        // De facto standard
+        else if (name === "acosh" && arity === 1)
+        {
+            if (v[0] < 1)
+                return evaluation_error("undefined");
+            evaluated.value = Math.acosh(v[0]);
+        }
+        else if (name === "asinh" && arity === 1)
+            evaluated.value = Math.asinh(v[0]);
+        else if (name === "atanh" && arity === 1)
+        {
+            if (v[0] >= 1)
+                return evaluation_error("undefined");
+            evaluated.value = Math.atanh(v[0]);
+        }
+        else if (name === "cosh" && arity === 1)
+            evaluated.value = Math.cosh(v[0]);
+        else if (name === "sinh" && arity === 1)
+            evaluated.value = Math.sinh(v[0]);
+        else if (name === "tanh" && arity === 1)
+            evaluated.value = Math.tanh(v[0]);
+		// Others
         else if (name === "random" && arity === 1) {
             // random(L) returns integer X in range 0 =< X < L.
             let max = Math.floor(v[0]);