Add delete! operation to metadata abstractions.

diff --git a/src/runtime/global.scm b/src/runtime/global.scm
index 0627959ef9d4367ced8f1bc55c7cc56848dc5942..7d84dc0163be54d15162eaba6b296291d026e849 100644 (file)
--- a/src/runtime/global.scm
+++ b/src/runtime/global.scm
@@ -507,6 +507,13 @@ USA.
              (set! alist (cons (cons key metadata) alist))
              unspecific))))
 
+    (define (delete! key)
+      (set! alist
+           (remove! (lambda (p)
+                      (eqv? (car p) key))
+                    alist))
+      unspecific)
+
     (define (get-alist)
       alist)
 
@@ -520,6 +527,7 @@ USA.
        ((has?) has?)
        ((get) get)
        ((put!) put!)
+       ((delete!) delete!)
        ((get-alist) get-alist)
        ((put-alist!) put-alist!)
        (else (error "Unknown operator:" operator))))))
@@ -536,6 +544,9 @@ USA.
     (define (put! key metadata)
       (hash-table-set! table key metadata))
 
+    (define (delete! key)
+      (hash-table-delete! table key))
+
     (define (get-alist)
       (hash-table->alist table))
 
@@ -549,6 +560,7 @@ USA.
        ((has?) has?)
        ((get) get)
        ((put!) put!)
+       ((delete!) delete!)
        ((get-alist) get-alist)
        ((put-alist!) put-alist!)
        (else (error "Unknown operator:" operator))))))