1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/Pure/ProofGeneral/syntax_standalone.ML Wed Jan 03 21:00:24 2007 +0100
1.3 @@ -0,0 +1,33 @@
1.4 +(* Taken from ../Syntax/lexicon.ML, which otherwise pulls in whole
1.5 + term structure of Isabelle
1.6 +*)
1.7 +signature SYNTAX =
1.8 +sig
1.9 + val read_int: string -> int option
1.10 + val read_nat: string -> int option
1.11 +end
1.12 +
1.13 +structure Syntax : SYNTAX =
1.14 +struct
1.15 +
1.16 +local
1.17 +
1.18 +val scan_digits1 = Scan.many1 Symbol.is_digit;
1.19 +
1.20 +fun nat cs =
1.21 + Option.map (#1 o Library.read_int)
1.22 + (Scan.read Symbol.stopper scan_digits1 cs);
1.23 +
1.24 +in
1.25 +
1.26 +val read_nat = nat o Symbol.explode;
1.27 +
1.28 +fun read_int s =
1.29 + (case Symbol.explode s of
1.30 + "-" :: cs => Option.map ~ (nat cs)
1.31 + | cs => nat cs);
1.32 +
1.33 +end;
1.34 +
1.35 +end
1.36 +