The CICS parser conforms to the language as defined by IBM. The parser does build a syntax tree. The parser can operate stand alone or it can be attached to the parsers for COBOL, PL/I and C in order to analyze embedded statements enclosed in EXEC CICS directives.
References
IBM, CICS/ESA, Application Programming Reference, Version 4 Release 1, First edition (October 1994), Document Number SC33-1170-00