X-Git-Url: http://git.kpe.io/?a=blobdiff_plain;ds=inline;f=doc%2Fintro.sgml;h=6f8b9b6f7e02744127624e191c9d62fc9e5b8183;hb=7fcec7e8319f5b11c8f501b6a869142cd26a8bdd;hp=a42cc8d1d4ec744a0f18598bd9ac76209ce536c8;hpb=192193db6e4fbda90a840474d4aa2e8762597927;p=uffi.git
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
@@ -45,20 +47,53 @@
-
- Installation
-
- Installation is fairly simple. The main requirement is that you
- have a copy of &defsystem;. You can download the latest version
- of &defsystem; from the
- CLOCC
- CVS tree. After installing &defsystem;, simply
- push the
- directory containing &uffi; into
- mk:*central-registry*. Whenever you
-want to load the &uffi; package, use the function
- (mk:oos :uffi 'load).
-
-
+
+ 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.
+
+
+
+
+
+