diff options
Diffstat (limited to 'guix/records.scm')
| -rw-r--r-- | guix/records.scm | 30 |
1 files changed, 13 insertions, 17 deletions
diff --git a/guix/records.scm b/guix/records.scm index f66fda8a32..dbdd2201a6 100644 --- a/guix/records.scm +++ b/guix/records.scm @@ -142,6 +142,17 @@ fields, and DELAYED is the list of identifiers of delayed fields." '(expected ...) fields))))))))))))) +(define-syntax-rule (define-field-property-predicate predicate property) + "Define PREDICATE as a procedure that takes a syntax object and, when passed +a field specification, returns the field name if it has the given PROPERTY." + (define (predicate s) + (syntax-case s (property) + ((field (property values (... ...)) _ (... ...)) + #'field) + ((field _ properties (... ...)) + (predicate #'(field properties (... ...)))) + (_ #f)))) + (define-syntax define-record-type* (lambda (s) "Define the given record type such that an additional \"syntactic @@ -189,23 +200,8 @@ field." (field-default-value #'(field options ...))) (_ #f))) - (define (delayed-field? s) - ;; Return the field name if the field defined by S is delayed. - (syntax-case s (delayed) - ((field (delayed) _ ...) - #'field) - ((field _ options ...) - (delayed-field? #'(field options ...))) - (_ #f))) - - (define (thunked-field? s) - ;; Return the field name if the field defined by S is thunked. - (syntax-case s (thunked) - ((field (thunked) _ ...) - #'field) - ((field _ options ...) - (thunked-field? #'(field options ...))) - (_ #f))) + (define-field-property-predicate delayed-field? delayed) + (define-field-property-predicate thunked-field? thunked) (define (wrapped-field? s) (or (thunked-field? s) (delayed-field? s))) |