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diff --git a/doc/intro.sgml b/doc/intro.sgml
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--- a/doc/intro.sgml
+++ b/doc/intro.sgml
@@ -5,8 +5,8 @@
Purpose
This reference guide describes
- &uffi;, a Lisp package that provides persistent cross-implementation
- support of C-language compatible libraries.
+ &uffi;, a package that provides a cross-implementation
+ interface from Common Lisp to C-language compatible libraries.
@@ -16,10 +16,12 @@
Every Common Lisp implementation has
a method for interfacing to C-language compatible
- libraries. Unfortunately, these method vary widely amongst
- implementations. Currently, to support multiple implementations,
- developers must write a different interface library for each Common
- Lisp implementation.
+ libraries. These methods are often termed a
+ Foreign Function Library Interface
+ (&ffi;). Unfortunately, these methods vary widely
+ amongst
+ implementations, thus preventing the writing of a portable FFI to a
+particular C-library.
&uffi; gathers a common subset of functionality between Common Lisp
@@ -46,15 +48,52 @@
- Design Overview
-
- &uffi; was designed as a cross-implementation compatible
- Foreign Function Interface. Necessarily,
- only a common subset of functionality can be
- provided. Likewise, not every optimization for that a specific
- implementation provides can be supported. Wherever possible,
- though, implementation-specific optimizations are invoked.
-
+ Design
+
+ Overview
+
+ &uffi; was designed as a cross-implementation
+ compatible Foreign Function Interface.
+ Necessarily,
+ only a common subset of functionality can be
+ provided. Likewise, not every optimization for that a specific
+ implementation provides can be supported. Wherever possible,
+ though, implementation-specific optimizations are invoked.
+
+
+
+
+ Priorities
+
+ The design of &uffi; is dictated by the order of these priorities:
+
+
+
+
+ Code using &uffi; must operate correctly on all
+ supported implementations.
+
+
+
+
+ Take advantage of implementation-specific optimizations. Ideally,
+ there will not a situation where an implementation-specific
+ &ffi; will be chosen due to lack of optimizations in &uffi;.
+
+
+
+ Provide a simple interface to developers using
+&uffi;. This priority is quite a bit lower than the above priorities.
+This lower priority is manifest by programmers having to pass types in
+pointer and array dereferencing, needing to use
+cstring wrapper functions, and the use of
+ensure-char-character and ensure-char-integer functions. My hope is
+that the developer inconvenience will be outweighed by the generation
+of optimized code that is cross-implementation compatible.
+
+
+
+