X-Git-Url: http://git.kpe.io/?a=blobdiff_plain;ds=sidebyside;f=doc%2Fref.sgml;h=39ae02ebaf9a920fceb1b76cef1a1671bd0f70fb;hb=005eb1c1210634a27fbc973d84004b5622456fc5;hp=7c103ab77946a83446cb7ef106d7e4b476b54295;hpb=6e2c62a3ed1ab7f5a09775fd6af10a1f1d23320c;p=uffi.git

diff --git a/doc/ref.sgml b/doc/ref.sgml
index 7c103ab..39ae02e 100644
--- a/doc/ref.sgml
+++ b/doc/ref.sgml
@@ -96,8 +96,12 @@ dereferenced :char pointer returns an character.</para>
 pointer returns an character.</para>
 	  </listitem>
 	  <listitem>
-	    <para><constant>:byte</constant> - Unsigned 8-bits. A
+	    <para><constant>:byte</constant> - Signed 8-bits. A
 dereferenced :byte pointer returns an integer.</para>
+          </listitem>
+	  <listitem>
+	    <para><constant>:unsigned-byte</constant> - Unsigned 8-bits. A
+dereferenced :unsigned-byte pointer returns an integer.</para>
 	  </listitem>
 	  <listitem>
 	    <para><constant>:short</constant> - Signed 16-bits.</para>
@@ -1046,6 +1050,61 @@ much better with static allocation.
       </refsect1>
     </refentry>
 
+    <refentry id="size-of-foreign-type">
+      <refnamediv>
+	<refname>size-of-foreign-type</refname>
+	<refpurpose>Returns the number of data bytes used by a foreign object type.
+	</refpurpose>
+	<refclass>Macro</refclass>
+      </refnamediv>
+      <refsynopsisdiv>
+	<title>Syntax</title>
+	<synopsis>
+	  <function>size-of-foreign-type</function> <replaceable>ftype</replaceable>
+	</synopsis>
+      </refsynopsisdiv>
+      <refsect1>
+	<title>Arguments and Values</title>
+	<variablelist>
+	  <varlistentry>
+	    <term><parameter>ftype</parameter></term>
+	    <listitem>
+	      <para>A foreign type specifier. This parameter is evaluated.
+	      </para>
+	    </listitem>
+	  </varlistentry>
+	</variablelist>
+      </refsect1>
+      <refsect1>
+	<title>Description</title>
+	<para>
+	  Returns the number of data bytes used by a foreign object type. This does not include any Lisp storage overhead.
+	</para>
+      </refsect1>
+      <refsect1>
+	<title>Examples</title>
+	<para>
+<programlisting>
+(size-of-foreign-object :unsigned-byte)
+=> 1
+(size-of-foreign-object 'my-100-byte-vector-type)
+=> 100
+</programlisting>
+        </para>
+      </refsect1>
+      <refsect1>
+	<title>Side Effects</title>
+	<para>None.</para>
+      </refsect1>      <refsect1>
+	<title>Affected by</title>
+	<para>None.</para>
+      </refsect1>
+      <refsect1>
+	<title>Exceptional Situations</title>
+	<para>None.</para>
+      </refsect1>
+    </refentry>
+
     <refentry id="pointer-address">
       <refnamediv>
 	<refname>pointer-address</refname>
@@ -1436,12 +1495,23 @@ if a cstring returned by a function is &null;.
 <partintro>
 <title>Overview</title>
 <para>
-	  &uffi; has functions to two types of <varname>C</varname>-compatible 
+
+	  &uffi; has functions to two types of
+<varname>C</varname>-compatible
 	  strings, <emphasis>cstring</emphasis> and <emphasis>foreign</emphasis> strings.
-cstrings are used as parameters to and from functions. An implementation, such as CMUCL,
-may not convert these to a foreign type for efficiency sake. Thus, it is not
-possible to "allocate" a cstring. In contrast, foreign strings
-always need to have memory for them.
+
+cstrings are used as parameters to and from functions. An
+implementation, such as CMUCL and Lispworks, a cstring may not be a
+foreign type but rather the Lisp string itself while on other
+platforms a cstring is a newly allocated foreign vector for storing
+characters. Thus, it is not possible to portably
+<emphasis>allocate</emphasis> a cstring. 
+</para>
+<para>
+In contrast, foreign strings
+are always a foreign vector of characters which have a memory
+allocated to hold them. Because of this, if you need to allocate memory to
+hold the return value of a string, use a foreign string and not a cstring.
 	</para>
 </partintro>
 
@@ -1543,7 +1613,7 @@ that returns a cstring.
       </refsect1>
       <refsect1>
 	<title>Side Effects</title>
-	<para>None.</para>
+	<para>On some implementations, this function allocates memory.</para>
       </refsect1>
       <refsect1>
 	<title>Affected by</title>
@@ -1645,7 +1715,7 @@ that returns a cstring.
       <refsect1>
 	<title>Description</title>
 	<para>
-	  Binds a lexical variable to a newly allocated <varname>cstring</varname>. Automatically frees <varname>cstring</varname>.
+	  Binds a symbol to a cstring created from conversion of a string. Automatically frees the <varname>cstring</varname>.
 	</para>
       </refsect1>
       <refsect1>