* [bug#54652] [PATCH 1/2] guix: Only check the object type once in the MATCH-RECORD expansion.
@ 2022-03-31 12:46 Attila Lendvai
2022-03-31 12:52 ` [bug#54652] [PATCH 2/2] guix: MATCH-RECORD supports (FIELD-NAME VARIABLE-NAME) forms Attila Lendvai
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Attila Lendvai @ 2022-03-31 12:46 UTC (permalink / raw)
To: 54652; +Cc: Attila Lendvai
* guix/records.scm (match-record/fields): New macro.
(match-record): Only check the object type once in the expansion.
---
guix/records.scm | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
diff --git a/guix/records.scm b/guix/records.scm
index ed94c83dac..e311086d73 100644
--- a/guix/records.scm
+++ b/guix/records.scm
@@ -535,17 +535,25 @@ (define (recutils->alist port)
(else
(error "unmatched line" line))))))))
+(define-syntax match-record/fields
+ (syntax-rules ()
+ ((_ record type (field fields ...) body ...)
+ (let ((field ((record-accessor type 'field) record)))
+ ;; TODO compute indices and report wrong-field-name errors at
+ ;; expansion time
+ ;; TODO support thunked and delayed fields
+ (match-record/fields record type (fields ...) body ...)))
+ ((_ record type () body ...)
+ (begin body ...))))
+
(define-syntax match-record
(syntax-rules ()
"Bind each FIELD of a RECORD of the given TYPE to it's FIELD name.
The current implementation does not support thunked and delayed fields."
((_ record type (field fields ...) body ...)
(if (eq? (struct-vtable record) type)
- ;; TODO compute indices and report wrong-field-name errors at
- ;; expansion time
- ;; TODO support thunked and delayed fields
- (let ((field ((record-accessor type 'field) record)))
- (match-record record type (fields ...) body ...))
+ ;; So that we only test the type once.
+ (match-record/fields record type (field fields ...) body ...)
(throw 'wrong-type-arg record)))
((_ record type () body ...)
(begin body ...))))
--
2.34.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [bug#54652] [PATCH 2/2] guix: MATCH-RECORD supports (FIELD-NAME VARIABLE-NAME) forms.
2022-03-31 12:46 [bug#54652] [PATCH 1/2] guix: Only check the object type once in the MATCH-RECORD expansion Attila Lendvai
@ 2022-03-31 12:52 ` Attila Lendvai
2022-06-30 13:56 ` [bug#54652] (No Subject) Attila Lendvai
2022-11-20 14:18 ` bug#54652: " Attila Lendvai
2 siblings, 0 replies; 4+ messages in thread
From: Attila Lendvai @ 2022-03-31 12:52 UTC (permalink / raw)
To: 54652; +Cc: Attila Lendvai
E.g. (match-record obj <type> (field1 (field2 var-name)) ...)
* guix/records.scm (match-record/fields): Implement it.
---
a real world example i was facing: a field name is the same
as an object constructor, and thus shadows it in a
match-record form, unless a different variable name is chosen.
guix/records.scm | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/guix/records.scm b/guix/records.scm
index e311086d73..492ab2aed6 100644
--- a/guix/records.scm
+++ b/guix/records.scm
@@ -537,12 +537,15 @@ (define (recutils->alist port)
(define-syntax match-record/fields
(syntax-rules ()
- ((_ record type (field fields ...) body ...)
- (let ((field ((record-accessor type 'field) record)))
+ ((_ record type ((field-name variable-name) fields ...) body ...)
+ (let ((variable-name ((record-accessor type 'field-name) record)))
;; TODO compute indices and report wrong-field-name errors at
;; expansion time
;; TODO support thunked and delayed fields
(match-record/fields record type (fields ...) body ...)))
+ ((_ record type (field fields ...) body ...)
+ ;; Channel it back into the canonical form above.
+ (match-record/fields record type ((field field) fields ...) body ...))
((_ record type () body ...)
(begin body ...))))
--
2.34.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [bug#54652] (No Subject)
2022-03-31 12:46 [bug#54652] [PATCH 1/2] guix: Only check the object type once in the MATCH-RECORD expansion Attila Lendvai
2022-03-31 12:52 ` [bug#54652] [PATCH 2/2] guix: MATCH-RECORD supports (FIELD-NAME VARIABLE-NAME) forms Attila Lendvai
@ 2022-06-30 13:56 ` Attila Lendvai
2022-11-20 14:18 ` bug#54652: " Attila Lendvai
2 siblings, 0 replies; 4+ messages in thread
From: Attila Lendvai @ 2022-06-30 13:56 UTC (permalink / raw)
To: 54652@debbugs.gnu.org
one questionable thing: if fields is the empty list, then it skips entirely the runtime assert that checks the record type.
^ permalink raw reply [flat|nested] 4+ messages in thread
* bug#54652: (No Subject)
2022-03-31 12:46 [bug#54652] [PATCH 1/2] guix: Only check the object type once in the MATCH-RECORD expansion Attila Lendvai
2022-03-31 12:52 ` [bug#54652] [PATCH 2/2] guix: MATCH-RECORD supports (FIELD-NAME VARIABLE-NAME) forms Attila Lendvai
2022-06-30 13:56 ` [bug#54652] (No Subject) Attila Lendvai
@ 2022-11-20 14:18 ` Attila Lendvai
2 siblings, 0 replies; 4+ messages in thread
From: Attila Lendvai @ 2022-11-20 14:18 UTC (permalink / raw)
To: 54652-close@debbugs.gnu.org
closing, it was superseded by #59390
https://issues.guix.gnu.org/59390
--
• attila lendvai
• PGP: 963F 5D5F 45C7 DFCD 0A39
--
“Personal dishonesty is not needed to produce a dishonest business plan or research proposal. Wishful thinking suffices.”
— John McCarthy (1927–2011), father of Lisp
^ permalink raw reply [flat|nested] 4+ messages in thread
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2022-03-31 12:46 [bug#54652] [PATCH 1/2] guix: Only check the object type once in the MATCH-RECORD expansion Attila Lendvai
2022-03-31 12:52 ` [bug#54652] [PATCH 2/2] guix: MATCH-RECORD supports (FIELD-NAME VARIABLE-NAME) forms Attila Lendvai
2022-06-30 13:56 ` [bug#54652] (No Subject) Attila Lendvai
2022-11-20 14:18 ` bug#54652: " Attila Lendvai
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