X-Git-Url: https://git.jsancho.org/?p=bongodb.git;a=blobdiff_plain;f=src%2Fbongodb.scm;h=3e5dc680c115c49e5fa79f00eca1661e9952da90;hp=e4df14bde9e1699503e91b4b9d6b9883446ba0b1;hb=a5972febd232c4afd64499826c7faab85a10ee03;hpb=0fe9f925e00b6899f3b685082ed9b3374933c527

diff --git a/src/bongodb.scm b/src/bongodb.scm
index e4df14b..3e5dc68 100644
--- a/src/bongodb.scm
+++ b/src/bongodb.scm
@@ -24,7 +24,13 @@
 	    collection?
 	    count
 	    insert
-	    find))
+	    find
+	    update
+	    $eq
+	    $exists
+	    $not
+	    $and
+	    $set))
 
 
 ;;; Collection Definition
@@ -76,27 +82,73 @@
 	     (values rescol (cons docid docids)))))))
 
 (define (find col filter)
+  "Query the collection and return the documents that match with filter"
+  (map vhash->alist (inner-find col filter)))
+
+(define (inner-find col filter)
   "Query the collection and return the documents that match with filter"
   (let ((table (get-table col)))
     (vhash-fold
      (lambda (key document result)
        (cond ((match-document? document filter)
-	      (cons (vhash->alist document) result))
+	      (cons document result))
 	     (else
 	      result)))
      '()
      table)))
 
 (define (match-document? document filter)
-  "Try to match the given document with a list of conditions"
-  (cond ((null? filter)
+  "Try to match the given document with a given filter"
+  (cond ((equal? filter #t)
 	 #t)
 	(else
-	 (and
-	  (equal? (vhash-assoc (caar filter) document) (car filter))
-	  (match-document? document (cdr filter))))))
+	 (filter document))))
+
+(define (update col filter . changes)
+  "Update selected documents using the given filter"
+  (let ((documents (inner-find col filter)))
+    (apply insert (cons col (map (lambda (doc) (update-document doc changes)) documents)))))
+
+(define (update-document document changes)
+  "Update a document with the appropiate changes"
+  (cond ((null? changes)
+	 document)
+	(else
+	 (update-document ((car changes) document) (cdr changes)))))
+
+
+;;; Queries
+
+(define ($eq field value)
+  (lambda (document)
+    (let ((stored (vhash-assoc field document)))
+      (and stored
+	   (equal? (cdr stored) value)))))
+
+(define ($exists field)
+  (lambda (document)
+    (and (vhash-assoc field document)
+	 #t)))
+
+(define ($not expr)
+  (lambda (document)
+    (not (expr document))))
+
+(define-syntax $and
+  (syntax-rules ()
+    ((_ expr ...)
+     (lambda (document)
+       (and (expr document)
+	    ...)))))
+
+
+;;; Updates
 
+(define ($set field value)
+  (lambda (document)
+    (vhash-cons field value document)))
 
+	     
 ;;; Tools
 
 (define (vhash->alist vhash)