Patches from Ben Mather.

Allow #f to leave (srfi 99) record constructors and predicates undefined.
Distinguish default immutable fields (raw identifier), from default
mutable fields (list of one identifier) in the syntactic layer by not
creating setters for the immutable fields.  The record introspection
can still mutate such fields.
Fixes issue #190.

lib/srfi/99/records/syntactic.scm

@@ -37,14 +37,15 @@
                    (,(rename 'make-type-predicate)
                     ,(id->string pred-name)
                     ,name)))
-               #f)
+               '())
          ;; accessors
          ,@(map (lambda (f)
                   (let ((g (if (and (pair? f) (pair? (cdr f)))
                                (cadr f)
-                               (and (identifier? f)
                                (string->symbol
-                                     (string-append name-str "-" (id->string f)))))))
+                                 (string-append name-str
+                                                "-"
+                                                (id->string (if (pair? f) (car f) f)))))))
                     (and g
                          `(,_define ,g
                             (,(rename 'make-getter)
@@ -53,11 +54,14 @@
                              (,_type_slot_offset ,name ',(if (pair? f) (car f) f)))))))
                 fields)
          ,@(map (lambda (f)
-                  (let ((s (if (and (pair? f) (pair? (cdr f)) (pair? (cddr f)))
+                  (let ((s (and (pair? f)
+                                (if (and (pair? (cdr f)) (pair? (cddr f)))
                                     (car (cddr f))
-                               (and (identifier? f)
                                     (string->symbol
-                                     (string-append name-str "-" (id->string f) "-set!"))))))
+                                      (string-append name-str
+                                                     "-"
+                                                     (id->string (car f))
+                                                     "-set!"))))))
                     (and s
                          `(,_define ,s
                             (,(rename 'make-setter)
@@ -66,9 +70,10 @@
                              (,_type_slot_offset ,name ',(if (pair? f) (car f) f)))))))
                 fields)
          ;; constructor
-         ,(if make-fields
+         ,@(if make-name
+              (if make-fields
                 (let ((fields (map (lambda (f) (cons (rename f) f)) make-fields)))
-                `(,_define ,make-name
+                  `((,_define ,make-name
                      ,(let lp ((ls fields) (sets '()))
                         (cond
                          ((null? ls)
@@ -87,8 +92,8 @@
                                   (cons (list (car (cddr field)) 'res (cdar ls)) sets)))
                              (else
                               (lp (cdr ls)
-                                (cons `(,_slot-set! ,name res (,_type_slot_offset ,name ',(cdar ls)) ,(caar ls)) sets))))))))))
+                                  (cons `(,_slot-set! ,name res (,_type_slot_offset ,name ',(cdar ls)) ,(caar ls)) sets)))))))))))
-              `(,_define ,make-name
+                `((,_define ,make-name
                    (,_let ((,_make (,(rename 'make-constructor)
                                     ,(id->string make-name)
                                     ,name)))
@@ -107,4 +112,5 @@
                                     a))
                             (else
                              (,_slot-set! ,name res (,_type_slot_offset ,name (car p)) (car a))
-                           (lp (cdr a) (cdr p)))))))))))))))
+                             (lp (cdr a) (cdr p)))))))))))
+              '()))))))

tests/record-tests.scm

@@ -2,6 +2,7 @@
 (cond-expand
  (modules
   (import (srfi 99)
+          (only (chibi) env-exports)
           (only (chibi test) test-begin test-assert test test-end)))
  (else #f))
 
@@ -112,8 +113,8 @@
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
-(define-record-type person #t #t name sex age)
+(define-record-type person #t #t (name) (sex) (age))
-(define-record-type (employee person) #t #t department salary)
+(define-record-type (employee person) #t #t (department) (salary))
 
 (define bob (make-employee "Bob" 'male 28 'hr 50000.0))
 (define alice (make-employee "Alice" 'female 32 'research 100000.0))
@@ -148,9 +149,9 @@
 (test #f (employee-department bob))
 (test 0.0 (employee-salary bob))
 
-;;;; SRFI-99 forbids this, but we currently do it anyway.
+;; SRFI-99 forbids this, but we currently do it anyway.
-;;(test-assert (equal? (make-employee "Chuck" 'male 20 'janitorial 50000.0)
+(test-assert (equal? (make-employee "Chuck" 'male 20 'janitorial 50000.0)
-;;                     (make-employee "Chuck" 'male 20 'janitorial 50000.0)))
+                     (make-employee "Chuck" 'male 20 'janitorial 50000.0)))
 
 (test-assert (record? alice))
 (test 'person (rtd-name person))
@@ -169,7 +170,7 @@
 ;;   (make-foo x)
 ;;   foo?
 ;;   (x foo-x))
-
+;;
 ;; (test-assert (not (rtd-field-mutable? foo 'x)))
 
 (define point (make-rtd "point" #(x y)))
@@ -183,4 +184,39 @@
 (test-assert (example? (make-example 3)))
 (test 3 (example-example (make-example 3)))
 
+;; record types definitions with #f passed as either the constructor or
+;; predicate argument should not create the corresponding function
+
+(define-record-type abstract
+  #f #t)
+
+(test #f (memq 'make-abstract (env-exports (current-environment))))
+
+(define-record-type (derived abstract)
+  #t #f)
+
+(define instance (make-derived))
+(test-assert (abstract? instance))
+(test #f (memq 'derived? (env-exports (current-environment))))
+
+(define-record-type container
+  #t #t
+  default-immutable
+  (default-mutable)
+  (named-immutable get-container-immutable)
+  (named-mutable get-container-mutable set-container-mutable!))
+
+(define container-instance (make-container 1 2 3 4))
+
+(test 1 (container-default-immutable container-instance))
+(test 2 (container-default-mutable container-instance))
+(test 3 (get-container-immutable container-instance))
+(test 4 (get-container-mutable container-instance))
+
+(container-default-mutable-set! container-instance #t)
+(test #t (container-default-mutable container-instance))
+
+(set-container-mutable! container-instance #t)
+(test #t (get-container-mutable container-instance))
+
 (test-end)