From 070453480f85f6da664974114cab3b84b8580e26 Mon Sep 17 00:00:00 2001
From: Kamil Tekiela <tekiela246@gmail.com>
Date: Sat, 21 Dec 2024 02:29:30 +0000
Subject: [PATCH 1/2] Use "unit type" instead of "value type"

---
 language/types.xml                     |  2 +-
 language/types/declarations.xml        |  2 +-
 language/types/type-system.xml         | 28 +++++++++++++-------------
 language/types/{value.xml => unit.xml} | 17 ++++++++--------
 4 files changed, 25 insertions(+), 24 deletions(-)
 rename language/types/{value.xml => unit.xml} (64%)

diff --git a/language/types.xml b/language/types.xml
index 656ad32dd4d3..24e397f309d7 100644
--- a/language/types.xml
+++ b/language/types.xml
@@ -131,7 +131,7 @@ int(16)
  &language.types.void;
  &language.types.never;
  &language.types.relative-class-types;
- &language.types.value;
+ &language.types.unit;
  &language.types.iterable;
  &language.types.declarations;
  &language.types.type-juggling;
diff --git a/language/types/declarations.xml b/language/types/declarations.xml
index 0a4baf140692..fd3b9d589a43 100644
--- a/language/types/declarations.xml
+++ b/language/types/declarations.xml
@@ -271,7 +271,7 @@ Stack trace:
    <title>Union types</title>
    <warning>
     <simpara>
-     It is not possible to combine the two value types <type>false</type>
+     It is not possible to combine the two unit types <type>false</type>
      and <type>true</type> together in a union type.
      Use <type>bool</type> instead.
     </simpara>
diff --git a/language/types/type-system.xml b/language/types/type-system.xml
index e71f3be231c0..fd7ad8b6eca7 100644
--- a/language/types/type-system.xml
+++ b/language/types/type-system.xml
@@ -27,9 +27,6 @@
     <listitem>
      <simpara>Built-in types</simpara>
      <itemizedlist>
-      <listitem>
-       <simpara><type>null</type> type</simpara>
-      </listitem>
       <listitem>
        <simpara>
         Scalar types:
@@ -70,18 +67,21 @@
         <type>self</type>, <type>parent</type>, and <type>static</type>
        </simpara>
       </listitem>
-     </itemizedlist>
-    </listitem>
-    <listitem>
-     <simpara>
-      <link linkend="language.types.value">Value types</link>
-     </simpara>
-     <itemizedlist>
-      <listitem>
-       <simpara><type>false</type></simpara>
-      </listitem>
       <listitem>
-       <simpara><type>true</type></simpara>
+       <simpara>
+        <link linkend="language.types.unit">Unit types</link>
+       </simpara>
+       <itemizedlist>
+        <listitem>
+         <simpara><type>false</type></simpara>
+        </listitem>
+        <listitem>
+         <simpara><type>true</type></simpara>
+        </listitem>
+        <listitem>
+         <simpara><type>null</type></simpara>
+        </listitem>
+       </itemizedlist>
       </listitem>
      </itemizedlist>
     </listitem>
diff --git a/language/types/value.xml b/language/types/unit.xml
similarity index 64%
rename from language/types/value.xml
rename to language/types/unit.xml
index 643bbe12525d..c6a067d60882 100644
--- a/language/types/value.xml
+++ b/language/types/unit.xml
@@ -1,24 +1,25 @@
 <?xml version="1.0" encoding="utf-8"?>
-<sect1 xml:id="language.types.value">
- <title>Value types</title>
+<sect1 xml:id="language.types.unit">
+ <title>Unit types</title>
 
  <para>
-  Value types are those which not only check the type of a value but also
-  the value itself. PHP has support for two value types:
-  <type>false</type> as of PHP 8.0.0, and <type>true</type>
-  as of PHP 8.2.0.
+  Unit types are those which allow only one value.
+  PHP has support for three unit types:
+  <type>false</type> as of PHP 8.0.0, <type>true</type>
+  as of PHP 8.2.0, and <type>null</type>.
  </para>
 
  <warning>
   <simpara>
-   Prior to PHP 8.2.0 the <type>false</type> type could only be used as part of a
+   Prior to PHP 8.2.0 the <type>false</type> and <type>null</type> type
+   could only be used as part of a
    <link linkend="language.types.type-system.composite.union">union type</link>.
   </simpara>
  </warning>
 
  <note>
   <simpara>
-   It is not possible to define custom value types. Consider using an
+   It is not possible to define custom unit types. Consider using an
    <link linkend="language.types.enumerations">enumerations</link> instead.
   </simpara>
  </note>

From 2c50802dcb09d24e7985e460d87ea8eb9c83a5a7 Mon Sep 17 00:00:00 2001
From: Kamil Tekiela <tekiela246@gmail.com>
Date: Wed, 15 Jan 2025 15:58:00 +0000
Subject: [PATCH 2/2] unit => singleton

---
 language/types.xml                         |  2 +-
 language/types/declarations.xml            |  2 +-
 language/types/{unit.xml => singleton.xml} | 16 ++++++++--------
 language/types/type-system.xml             |  9 ++++++++-
 4 files changed, 18 insertions(+), 11 deletions(-)
 rename language/types/{unit.xml => singleton.xml} (67%)

diff --git a/language/types.xml b/language/types.xml
index 24e397f309d7..14483ea5ce0a 100644
--- a/language/types.xml
+++ b/language/types.xml
@@ -131,7 +131,7 @@ int(16)
  &language.types.void;
  &language.types.never;
  &language.types.relative-class-types;
- &language.types.unit;
+ &language.types.singleton;
  &language.types.iterable;
  &language.types.declarations;
  &language.types.type-juggling;
diff --git a/language/types/declarations.xml b/language/types/declarations.xml
index fd3b9d589a43..4d63b80c95f1 100644
--- a/language/types/declarations.xml
+++ b/language/types/declarations.xml
@@ -271,7 +271,7 @@ Stack trace:
    <title>Union types</title>
    <warning>
     <simpara>
-     It is not possible to combine the two unit types <type>false</type>
+     It is not possible to combine the two singleton types <type>false</type>
      and <type>true</type> together in a union type.
      Use <type>bool</type> instead.
     </simpara>
diff --git a/language/types/unit.xml b/language/types/singleton.xml
similarity index 67%
rename from language/types/unit.xml
rename to language/types/singleton.xml
index c6a067d60882..97d7cb5e35b9 100644
--- a/language/types/unit.xml
+++ b/language/types/singleton.xml
@@ -1,17 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
-<sect1 xml:id="language.types.unit">
- <title>Unit types</title>
+<sect1 xml:id="language.types.singleton">
+ <title>Singleton types</title>
 
  <para>
-  Unit types are those which allow only one value.
-  PHP has support for three unit types:
-  <type>false</type> as of PHP 8.0.0, <type>true</type>
-  as of PHP 8.2.0, and <type>null</type>.
+  Singleton types are those which allow only one value.
+  PHP has support for two singleton types:
+  <type>false</type> as of PHP 8.0.0 and <type>true</type>
+  as of PHP 8.2.0.
  </para>
 
  <warning>
   <simpara>
-   Prior to PHP 8.2.0 the <type>false</type> and <type>null</type> type
+   Prior to PHP 8.2.0 the <type>false</type> type
    could only be used as part of a
    <link linkend="language.types.type-system.composite.union">union type</link>.
   </simpara>
@@ -19,7 +19,7 @@
 
  <note>
   <simpara>
-   It is not possible to define custom unit types. Consider using an
+   It is not possible to define custom singleton types. Consider using an
    <link linkend="language.types.enumerations">enumerations</link> instead.
   </simpara>
  </note>
diff --git a/language/types/type-system.xml b/language/types/type-system.xml
index fd7ad8b6eca7..2bac2d22809a 100644
--- a/language/types/type-system.xml
+++ b/language/types/type-system.xml
@@ -69,7 +69,7 @@
       </listitem>
       <listitem>
        <simpara>
-        <link linkend="language.types.unit">Unit types</link>
+        <link linkend="language.types.singleton">Singleton types</link>
        </simpara>
        <itemizedlist>
         <listitem>
@@ -78,6 +78,13 @@
         <listitem>
          <simpara><type>true</type></simpara>
         </listitem>
+       </itemizedlist>
+      </listitem>
+      <listitem>
+       <simpara>
+        Unit types
+       </simpara>
+       <itemizedlist>
         <listitem>
          <simpara><type>null</type></simpara>
         </listitem>