The JCL parser conforms to the language as defined by IBM. Besides JCL commands JES2 and JES3 control statements are accepted as well. The parser does build a syntax tree.
The system includes a JCL preprocessor. The preprocessor interprets macro definitions (PROC ... PEND) and macro calls (EXEC PROC) and it replaces macro parameters starting with the character &.
References
- OS/390 V2R5.0 MVS JCL Reference, IBM Corporation, Fifth Edition, March 1998, Document Number GC28-1757-04
- z/OS MVS JCL Reference, IBM, Tenth Edition, September 2005, Document Number SA22-7597-09