From 45af71be533a4148b83fab8a28e4b5154b6aefae Mon Sep 17 00:00:00 2001
From: "Tarn W. Burton" <twburton@gmail.com>
Date: Sun, 12 Nov 2023 16:06:01 -0500
Subject: [PATCH] Add gray:stream-file-length

---
 src/c/file.d         |  6 +++++-
 src/c/symbols_list.h |  1 +
 src/clos/streams.lsp | 15 +++++++++++++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/c/file.d b/src/c/file.d
index 650c3102c..a6a76dbef 100644
--- a/src/c/file.d
+++ b/src/c/file.d
@@ -1313,7 +1313,11 @@ clos_stream_element_type(cl_object strm)
   return _ecl_funcall2(@'gray::stream-element-type', strm);
 }
 
-#define clos_stream_length not_a_file_stream
+static cl_object
+clos_stream_length(cl_object strm)
+{
+  return _ecl_funcall2(@'gray::stream-file-length', strm);
+}
 
 static cl_object
 clos_stream_get_position(cl_object strm)
diff --git a/src/c/symbols_list.h b/src/c/symbols_list.h
index 5379959ac..d57f3f12d 100644
--- a/src/c/symbols_list.h
+++ b/src/c/symbols_list.h
@@ -1856,6 +1856,7 @@ cl_symbols[] = {
 {GRAY_ "STREAM-CLEAR-OUTPUT" ECL_FUN(NULL, NULL, -1) ECL_VAR(GRAY_ORDINARY, OBJNULL)},
 {GRAY_ "STREAM-ELEMENT-TYPE" ECL_FUN(NULL, NULL, 1) ECL_VAR(GRAY_ORDINARY, OBJNULL)},
 {GRAY_ "STREAM-FILE-DESCRIPTOR" ECL_FUN(NULL, NULL, -1) ECL_VAR(GRAY_ORDINARY, OBJNULL)},
+{GRAY_ "STREAM-FILE-LENGTH" ECL_FUN(NULL, NULL, -1) ECL_VAR(GRAY_ORDINARY, OBJNULL)},
 {GRAY_ "STREAM-FILE-POSITION" ECL_FUN(NULL, NULL, -1) ECL_VAR(GRAY_ORDINARY, OBJNULL)},
 {GRAY_ "STREAM-FINISH-OUTPUT" ECL_FUN(NULL, NULL, -1) ECL_VAR(GRAY_ORDINARY, OBJNULL)},
 {GRAY_ "STREAM-FORCE-OUTPUT" ECL_FUN(NULL, NULL, -1) ECL_VAR(GRAY_ORDINARY, OBJNULL)},
diff --git a/src/clos/streams.lsp b/src/clos/streams.lsp
index 3349ef17e..e462d5948 100644
--- a/src/clos/streams.lsp
+++ b/src/clos/streams.lsp
@@ -203,6 +203,10 @@
   (:documentation
    "This is like CL:FILE-POSITION, but for Gray streams."))
 
+(defgeneric stream-file-length (stream &optional position)
+  (:documentation
+   "This is like CL:FILE-LENGTH, but for Gray streams."))
+
 (defgeneric stream-file-descriptor (stream &optional direction)
   (:documentation
    "Return the file-descriptor underlaying STREAM, or NIL if not
@@ -593,6 +597,14 @@
   (declare (ignore stream position))
   nil)
 
+;; FILE-LENGTH
+
+(defmethod stream-file-length ((stream ansi-stream))
+  (file-length stream))
+
+(defmethod stream-file-length ((stream t))
+  (error 'type-error :datum stream :expected-type 'file-stream))
+
 ;; STREAM-P
 
 (defmethod streamp ((stream stream))
@@ -821,6 +833,9 @@ them so."
     (%redefine-cl-functions 'cl:file-position
                             'gray:stream-file-position
                             gray-package)
+    (%redefine-cl-functions 'cl:file-length
+                            'gray:stream-file-length
+                            gray-package)
     (si::package-lock "COMMON-LISP" x)
     nil))