added isAbsolute to uri.nim

lib/pure/uri.nim

@@ -245,6 +245,10 @@ proc combine*(uris: varargs[Uri]): Uri =
   for i in 1 .. <uris.len:
     result = combine(result, uris[i])
 
+proc isAbsolute*(uri: Uri): bool =
+  ## returns true if URI is absolute, false otherwise
+  return uri.scheme != "" and (uri.hostname != "" or uri.path != "")
+
 proc `/`*(x: Uri, path: string): Uri =
   ## Concatenates the path specified to the specified URI's path.
   ##
@@ -452,3 +456,14 @@ when isMainModule:
   block:
     let foo = parseUri("http://example.com") / "/baz"
     doAssert foo.path == "/baz"
+
+  # isAbsolute tests
+  block:
+    doAssert "www.google.com".parseUri().isAbsolute() == false
+    doAssert "http://www.google.com".parseUri().isAbsolute() == true
+    doAssert "/search".parseUri().isAbsolute() == false
+    doAssert "file:/dir/file".parseUri().isAbsolute() == true
+    doAssert "file://localhost/dir/file".parseUri().isAbsolute() == true
+    doAssert "https://example.org/URI/resource.txt".parseUri().isAbsolute() == true
+    doAssert "urn:ISSN:1535–3613".parseUri().isAbsolute() == true
+