literate: add with-terminal, suspend-backend, resume-backend to org source

with-terminal macro was only in tangled .lisp (not .org). suspend-backend
and resume-backend generics + simple-backend methods + tests were also
in hand-edited .lisp only. All three added to org/backend-protocol.org
with proper prose, following the literate programming discipline.

Also added suspend/resume assertions to simple-backend-lifecycle test suite.

src/backend/classes.lisp

@@ -8,47 +8,6 @@
 (defgeneric shutdown-backend (backend)
   (:method ((b backend)) (values)))
 
-(defgeneric suspend-backend (backend)
-  (:documentation "Temporarily suspend the backend, restoring terminal to normal state.
-Called before SIGTSTP or similar suspension. Application should redraw after resume.")
-  (:method ((b backend)) (values)))
-
-(defgeneric resume-backend (backend)
-  (:documentation "Re-initialize the backend after suspension.
-Called after SIGCONT or similar resume. Re-enables raw mode and backend features.")
-  (:method ((b backend)) (values)))
-
-(defmacro with-terminal ((backend-var &optional cols-var rows-var)
-                         &body body)
-  "Execute BODY with a fully initialized terminal backend.
-
-DETECT-BACKEND, INITIALIZE-BACKEND, and SHUTDOWN-BACKEND are called
-automatically.  The backend instance is bound to BACKEND-VAR.  If
-COLS-VAR and ROWS-VAR are provided, they are bound to the terminal
-dimensions at startup.
-
-The caller should wrap this in SB-POSIX:WITH-RAW-TERMINAL (or
-equivalent) if raw-mode input handling is needed.
-
-Example:
-  (with-terminal (be cols rows)
-    (loop for ev = (read-event be :timeout 0.1)
-          while ev
-          do (format t \"~A~%\" ev))))"
-  (let ((be-sym (gensym "BE"))
-        (c-sym (gensym "COLS"))
-        (r-sym (gensym "ROWS")))
-    `(let* ((,be-sym (detect-backend))
-            ,@(when cols-var `((,c-sym (nth-value 0 (backend-size ,be-sym)))))
-            ,@(when rows-var `((,r-sym (nth-value 1 (backend-size ,be-sym))))))
-       (initialize-backend ,be-sym)
-       (unwind-protect
-            (let ((,backend-var ,be-sym)
-                  ,@(when cols-var `((,cols-var ,c-sym)))
-                  ,@(when rows-var `((,rows-var ,r-sym))))
-              ,@body)
-         (shutdown-backend ,be-sym)))))
-
 (defgeneric backend-size (backend)
   (:method ((b backend))
     (values 80 24)))
@@ -103,3 +62,48 @@ Example:
   (:method ((b backend) feature)
     (declare (ignore feature))
     nil))
+
+(in-package :cl-tty.backend)
+
+(defgeneric suspend-backend (backend)
+  (:documentation "Temporarily suspend the backend, restoring terminal to normal state.
+Called before SIGTSTP or similar suspension. Application should redraw after resume.")
+  (:method ((b backend)) (values)))
+
+(defgeneric resume-backend (backend)
+  (:documentation "Re-initialize the backend after suspension.
+Called after SIGCONT or similar resume. Re-enables raw mode and backend features.")
+  (:method ((b backend)) (values)))
+
+(in-package :cl-tty.backend)
+
+(defmacro with-terminal ((backend-var &optional cols-var rows-var)
+                         &body body)
+  "Execute BODY with a fully initialized terminal backend.
+
+DETECT-BACKEND, INITIALIZE-BACKEND, and SHUTDOWN-BACKEND are called
+automatically.  The backend instance is bound to BACKEND-VAR.  If
+COLS-VAR and ROWS-VAR are provided, they are bound to the terminal
+dimensions at startup.
+
+The caller should wrap this in SB-POSIX:WITH-RAW-TERMINAL (or
+equivalent) if raw-mode input handling is needed.
+
+Example:
+  (with-terminal (be cols rows)
+    (loop for ev = (read-event be :timeout 0.1)
+          while ev
+          do (format t \"~A~%\" ev))))"
+  (let ((be-sym (gensym "BE"))
+        (c-sym (gensym "COLS"))
+        (r-sym (gensym "ROWS")))
+    `(let* ((,be-sym (detect-backend))
+            ,@(when cols-var `((,c-sym (nth-value 0 (backend-size ,be-sym)))))
+            ,@(when rows-var `((,r-sym (nth-value 1 (backend-size ,be-sym))))))
+       (initialize-backend ,be-sym)
+       (unwind-protect
+            (let ((,backend-var ,be-sym)
+                  ,@(when cols-var `((,cols-var ,c-sym)))
+                  ,@(when rows-var `((,rows-var ,r-sym))))
+              ,@body)
+         (shutdown-backend ,be-sym)))))