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.

org/backend-protocol.org

@@ -160,6 +160,8 @@ simple backend.
     (is (typep b 'simple-backend))
     (initialize-backend b)
     (is-false (capable-p b :truecolor) "simple backend has no truecolor")
+    (is (null (multiple-value-list (suspend-backend b))))
+    (is (null (multiple-value-list (resume-backend b))))
     (shutdown-backend b)))
 #+END_SRC
 
@@ -401,6 +403,7 @@ construction without actually rendering to a terminal.
    #:backend #:simple-backend
    ;; Lifecycle
    #:initialize-backend #:shutdown-backend
+   #:suspend-backend #:resume-backend
    #:backend-size #:backend-write #:backend-clear
    ;; Drawing
    #:draw-text #:draw-border #:draw-rect
@@ -414,8 +417,9 @@ construction without actually rendering to a terminal.
    ;; Queries
    #:capable-p
    ;; Constructors
-   #:make-simple-backend
+    #:make-simple-backend
-   ;; Modern backend
+    #:with-terminal
+    ;; Modern backend
    #:modern-backend #:make-modern-backend
    ;; Detection
    #:detect-backend #:*detected-backend*
@@ -664,6 +668,78 @@ keywords include ~:truecolor~, ~:osc8~, ~:sync~, ~:mouse~,
     nil))
 #+END_SRC
 
+*** Suspend and Resume
+
+Temporary terminal suspension and re-initialization. Used when the
+application receives SIGTSTP (suspend) or SIGCONT (resume) signals.
+The default methods are no-ops; backends with terminal state override
+these to restore cooked mode on suspend and raw mode on resume.
+
+#+BEGIN_SRC lisp :tangle ../src/backend/classes.lisp
+(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)))
+#+END_SRC
+
+*** With Terminal
+
+A convenience macro that initializes a terminal backend, executes body,
+and guarantees cleanup on exit via ~unwind-protect~.
+
+The macro detects a suitable backend, initializes it, captures the
+terminal dimensions, binds them to the provided variables, executes the
+body, and always calls ~shutdown-backend~ when the body exits (whether
+normally or by a non-local control transfer).
+
+Arguments:
+- ~backend-var~ — bound to the detected backend instance.
+- ~cols-var~, ~rows-var~ (optional) — bound to terminal columns and
+  lines captured after initialization.
+- ~&body body~ — executed with the above bindings.
+
+#+BEGIN_SRC lisp :tangle ../src/backend/classes.lisp
+(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)))))
+#+END_SRC
+
 ** Simple Backend
 
 ~simple-backend~ inherits from ~backend~ and implements every
@@ -721,6 +797,24 @@ restore. Returns multiple values to satisfy the protocol contract.
   (values))
 #+END_SRC
 
+*** Suspend (simple-backend)
+
+No-op — simple backend has no terminal state to save.
+
+#+begin_src lisp :tangle ../src/backend/simple.lisp
+(defmethod suspend-backend ((b simple-backend))
+  (values))
+#+end_src
+
+*** Resume (simple-backend)
+
+No-op — simple backend has no terminal state to restore.
+
+#+begin_src lisp :tangle ../src/backend/simple.lisp
+(defmethod resume-backend ((b simple-backend))
+  (values))
+#+end_src
+
 *** Backend Size (Simple)
 
 Returns hard-coded 80x24 dimensions. A real implementation would use

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)))))

src/backend/package.lisp

@@ -19,9 +19,9 @@
    ;; Queries
    #:capable-p
    ;; Constructors
-   #:make-simple-backend
+    #:make-simple-backend
-   #:with-terminal
+    #:with-terminal
-   ;; Modern backend
+    ;; Modern backend
    #:modern-backend #:make-modern-backend
    ;; Detection
    #:detect-backend #:*detected-backend*

src/backend/tests.lisp

@@ -24,6 +24,8 @@
     (is (typep b 'simple-backend))
     (initialize-backend b)
     (is-false (capable-p b :truecolor) "simple backend has no truecolor")
+    (is (null (multiple-value-list (suspend-backend b))))
+    (is (null (multiple-value-list (resume-backend b))))
     (shutdown-backend b)))
 
 (test simple-backend-draw-text
@@ -103,8 +105,6 @@
     (is (null (multiple-value-list (cursor-style b :block))))
     (is (null (multiple-value-list (begin-sync b))))
     (is (null (multiple-value-list (end-sync b))))
-    (is (null (multiple-value-list (suspend-backend b))))
-    (is (null (multiple-value-list (resume-backend b))))
     (shutdown-backend b)))
 
 (test sync-is-noop-on-simple