diff options
Diffstat (limited to 'recobj.scm')
| -rw-r--r-- | recobj.scm | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/recobj.scm b/recobj.scm new file mode 100644 index 0000000..caf55a6 --- /dev/null +++ b/recobj.scm @@ -0,0 +1,54 @@ +;;; "recobj.scm" Records implemented as objects. +;;;From: whumeniu@datap.ca (Wade Humeniuk) + +(require 'object) + +(define record-type-name (make-generic-method)) +(define record-accessor (make-generic-method)) +(define record-modifier (make-generic-method)) +(define record? (make-generic-predicate)) +(define record-constructor (make-generic-method)) + +(define (make-record-type type-name field-names) + (define self (make-object)) + + (make-method! self record-type-name + (lambda (self) + type-name)) + (make-method! self record-accessor + (lambda (self field-name) + (let ((index (comlist:position field-name field-names))) + (if (not index) + (slib:error "record-accessor: invalid field-name argument." + field-name)) + (lambda (obj) + (record-accessor obj index))))) + + (make-method! self record-modifier + (lambda (self field) + (let ((index (comlist:position field field-names))) + (if (not index) + (slib:error "record-accessor: invalid field-name argument." + field-name)) + (lambda (obj newval) + (record-modifier obj index newval))))) + + (make-method! self record? (lambda (self) #t)) + + (make-method! self record-constructor + (lambda (class . field-values) + (let ((values (apply vector field-values))) + (define self (make-object)) + (make-method! self record-accessor + (lambda (self index) + (vector-ref values index))) + (make-method! self record-modifier + (lambda (self index newval) + (vector-set! values index newval))) + (make-method! self record-type-name + (lambda (self) (record-type-name class))) + self))) + self) + +(provide 'record-object) +(provide 'record)
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