0.0.002

ddat interop with dat js
cable interop with cabal js
ddat's frontend = dat-thang
cable fe = cable-thang
dillo support based on cel's dillo-dat
bootstrap node
xplatform support

Signed-off-by: divo <418@cryspace.space>

scheme/dat-record.scm

@@ -0,0 +1,42 @@
+;;; Shared record conventions for Scheme-facing Dat APIs.
+;;; A record is (tag (field . value) ...); payload bytes stay bytevectors.
+
+(define (dat:record? value . wanted-tag)
+  (and (pair? value)
+       (symbol? (car value))
+       (or (null? wanted-tag) (eq? (car value) (car wanted-tag)))
+       (let loop ((fields (cdr value)) (seen '()))
+         (if (null? fields)
+             #t
+             (and (pair? fields)
+                  (pair? (car fields))
+                  (symbol? (caar fields))
+                  (not (memq (caar fields) seen))
+                  (loop (cdr fields) (cons (caar fields) seen)))))))
+
+(define (dat:record-ref record field . fallback)
+  (if (not (dat:record? record))
+      (error 'wrong-type-arg "expected a Dat record" record)
+      (if (not (symbol? field))
+          (error 'wrong-type-arg "record field name must be a symbol" field)
+          (let ((entry (assq field (cdr record))))
+            (if entry
+                (cdr entry)
+                (if (pair? fallback) (car fallback) #f))))))
+
+(define (dat:record-set record field value)
+  (if (not (dat:record? record))
+      (error 'wrong-type-arg "expected a Dat record" record)
+      (if (not (symbol? field))
+          (error 'wrong-type-arg "record field name must be a symbol" field)
+          (let loop ((fields (cdr record)) (reversed '()) (found #f))
+            (if (null? fields)
+                (cons (car record)
+                      (reverse (if found reversed
+                                   (cons (cons field value) reversed))))
+                (let ((entry (car fields)))
+                  (if (eq? (car entry) field)
+                      (loop (cdr fields) (cons (cons field value) reversed) #t)
+                      (loop (cdr fields) (cons entry reversed) found))))))))
+
+(provide 'dat:record)