* Document --eval-only and --parse-only options in nix-instantiate.

doc/manual/nix-instantiate.xml

@@ -8,6 +8,10 @@
     <cmdsynopsis>
       <command>nix-instantiate</command>
       &opt-common-syn;
+      <group choice='opt'>
+        <arg choice='plain'><option>--parse-only</option></arg>
+        <arg choice='plain'><option>--eval-only</option></arg>
+      </group>
       <arg choice='plain' rep='repeat'><replaceable>files</replaceable></arg>
     </cmdsynopsis>
   </refsynopsisdiv>
@@ -39,6 +43,27 @@
 
       &opt-common;
 
+      <varlistentry>
+        <term><option>--parse-only</option></term>
+        <listitem>
+          <para>
+            Just parse the input files, and print their abstract
+            syntax trees on standard output in ATerm format.
+          </para>
+        </listitem>
+      </varlistentry>
+      
+      <varlistentry>
+        <term><option>--eval-only</option></term>
+        <listitem>
+          <para>
+            Just parse and evaluate the input files, and print the
+            resulting values on standard output.  No instantiation of
+            store expressions takes place.
+          </para>
+        </listitem>
+      </varlistentry>
+
     </variablelist>
 
   </refsection>

doc/manual/opt-common-syn.xml

@@ -16,3 +16,4 @@
 <arg><option>--keep-failed</option></arg>
 <arg><option>-K</option></arg>
 <arg><option>--fallback</option></arg>
+<arg><option>--readonly-mode</option></arg>

doc/manual/opt-common.xml

@@ -171,3 +171,14 @@
   </listitem>
 </varlistentry>
 
+
+<varlistentry>
+  <term><option>--readonly-mode</option></term>
+  <listitem>
+    <para>
+      When this option is used, no attempt is made to open the Nix
+      database.  Most Nix operations do need database access, so those
+      operations will fail.
+    </para>
+  </listitem>
+</varlistentry>

src/nix-instantiate/help.txt

@@ -10,6 +10,7 @@ Options:
   --version: output version information
   --help: display help
 
-Options:
-
   --verbose / -v: verbose operation (may be repeated)
+
+  --eval-only: evaluate and print resulting term; do not instantiate
+  --parse-only: parse and print abstract syntax tree