Initial data commit

Task/Canonicalize-CIDR/Factor/canonicalize-cidr.factor

@@ -0,0 +1,22 @@
+USING: command-line formatting grouping io kernel math.parser
+namespaces prettyprint sequences splitting ;
+IN: rosetta-code.canonicalize-cidr
+
+! canonicalize a CIDR block: make sure none of the host bits are set
+command-line get [ lines ] when-empty
+[
+    ! ( CIDR-IP -- bits-in-network-part dotted-decimal )
+    "/" split first2 string>number swap
+
+    ! get IP as binary string
+    "." split [ string>number "%08b" sprintf ] map "" join
+
+    ! replace the host part with all zeros
+    over cut length [ CHAR: 0 ] "" replicate-as append
+
+    ! convert back to dotted-decimal
+    8 group [ bin> number>string ] map "." join swap
+
+    ! and output
+    "%s/%d\n" printf
+] each