/* START OF: rdc_lex_.incl.pl1 * * * * * * * * * * * * * * * * */ /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* */ /* N__a_m_e: rdc_lex_.incl.pl1 */ /* */ /* This include segment is used by compilers generated by the reduction_compiler. */ /* It contains the LEX subroutine which is used to manipulate the pointer to the */ /* "current" token, Pthis_token. */ /* */ /* E__n_t_r_y: LEX */ /* */ /* This entry makes the |_nth|-next (or -preceding) token the "current" token, where */ /* _n is its positive (or negative) input argument. */ /* */ /* U__s_a_g_e */ /* */ /* call LEX(n); */ /* */ /* 1) n is the number of the token to be made the "current" token, relative to the */ /* token identified by Pthis_token (the present "current" token). If n is */ /* positive, the nth token following the "current" token made "current". If n */ /* is negative, the nth token preceding the "current" token is made "current". */ /* */ /* S__t_a_t_u_s */ /* */ /* 0) Created by: G. C. Dixon in February, 1975 */ /* */ /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ LEX: procedure (n); dcl n fixed bin, i fixed bin; Ptoken = Pthis_token; /* do everything relative to "current" token. */ if Ptoken = null then return; /* can't lex if token list exhausted. */ if n >= 0 then do; /* new "current" token will follow present one. */ do i = 1 to n while (token.Pnext ^= null); /* find new "current" token, taking care not to */ Ptoken = token.Pnext; /* run off end of token list. */ end; if ^SPDL then if i <= n then Ptoken = null; /* if not in 'PUSH DOWN LANGUAGE' mode, allow */ /* running off end of token list. */ end; else /* new "current" token precedes present one. */ do i = -1 to n by -1 while (token.Plast ^= null); Ptoken = token.Plast; end; Pthis_token = Ptoken; /* simple wasn't it. */ end LEX; /* END OF: rdc_lex_.incl.pl1 * * * * * * * * * * * * * * * * */ */ ----------------------------------------------------------- Historical Background This edition of the Multics software materials and documentation is provided and donated to Massachusetts Institute of Technology by Group Bull including Bull HN Information Systems Inc. as a contribution to computer science knowledge. This donation is made also to give evidence of the common contributions of Massachusetts Institute of Technology, Bell Laboratories, General Electric, Honeywell Information Systems Inc., Honeywell Bull Inc., Groupe Bull and Bull HN Information Systems Inc. to the development of this operating system. Multics development was initiated by Massachusetts Institute of Technology Project MAC (1963-1970), renamed the MIT Laboratory for Computer Science and Artificial Intelligence in the mid 1970s, under the leadership of Professor Fernando Jose Corbato. Users consider that Multics provided the best software architecture for managing computer hardware properly and for executing programs. Many subsequent operating systems incorporated Multics principles. Multics was distributed in 1975 to 2000 by Group Bull in Europe , and in the U.S. by Bull HN Information Systems Inc., as successor in interest by change in name only to Honeywell Bull Inc. and Honeywell Information Systems Inc. . ----------------------------------------------------------- Permission to use, copy, modify, and distribute these programs and their documentation for any purpose and without fee is hereby granted,provided that the below copyright notice and historical background appear in all copies and that both the copyright notice and historical background and this permission notice appear in supporting documentation, and that the names of MIT, HIS, Bull or Bull HN not be used in advertising or publicity pertaining to distribution of the programs without specific prior written permission. Copyright 1972 by Massachusetts Institute of Technology and Honeywell Information Systems Inc. Copyright 2006 by Bull HN Information Systems Inc. Copyright 2006 by Bull SAS All Rights Reserved */