Predefined mode bits to control recognition of tokens. For instance, to configure a Scanner such that it only recognizes (Go) identifiers, integers, and skips comments, set the Scanner's Mode field to:

ScanIdents | ScanInts | SkipComments

With the exceptions of comments, which are skipped if SkipComments is set, unrecognized tokens are not ignored. Instead, the scanner simply returns the respective individual characters (or possibly sub-tokens). For instance, if the mode is ScanIdents (not ScanStrings), the string "foo" is scanned as the token sequence '"' Ident '"'.