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Diffstat (limited to 'pl/plparse.h')
| -rw-r--r-- | pl/plparse.h | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/pl/plparse.h b/pl/plparse.h new file mode 100644 index 000000000..ede05f4c7 --- /dev/null +++ b/pl/plparse.h @@ -0,0 +1,62 @@ +/* Portions Copyright (C) 2001 artofcode LLC. + Portions Copyright (C) 1996, 2001 Artifex Software Inc. + Portions Copyright (C) 1988, 2000 Aladdin Enterprises. + This software is based in part on the work of the Independent JPEG Group. + All Rights Reserved. + + This software is distributed under license and may not be copied, modified + or distributed except as expressly authorized under the terms of that + license. Refer to licensing information at http://www.artifex.com/ or + contact Artifex Software, Inc., 101 Lucas Valley Road #110, + San Rafael, CA 94903, (415)492-9861, for further information. */ +/*$Id$ */ + +/* plparse.h */ +/* Interface to all (H-P) language parsers */ + +#ifndef plparse_INCLUDED +# define plparse_INCLUDED + +#include "scommon.h" + +/* + * H-P printers can switch languages more or less ad lib. Currently, + * we have to be able to handle 4 languages: PJL, PCL5*, HP-GL/2, + * and PCL XL. This file provides a tiny bit of structure common to + * all languages and parsers, for the use of front-end programs that + * don't want to worry about such things. + * + * At any given moment, the interpreter's state consists of: + * - Job parameters set by some mix of PJL and the current language; + * - User defaults for the current language; + * - Parsing state for the current language; + * - Parameters, graphics state, and downloaded data for the current + * language. + * Currently we don't try to impose much structure on this, only enough + * to make it possible to write the language switching code. + */ +/* + * Define an abstract type for the switchable input processor state. + */ +typedef struct pl_process_state_s pl_process_state_t; +/* + * Define the type for a parser. The parser reads data from the input + * buffer and returns either: + * >=0 - OK, more input is needed. + * e_ExitLanguage - A UEL or other return to the default parser was + * detected. + * other <0 value - an error was detected. + */ +#define e_ExitLanguage (-102) /* e_InterpreterExit */ +#define pl_process_proc(proc)\ + int proc(pl_process_state_t *process_data, stream_cursor_read *pr) +typedef pl_process_proc((*pl_process_proc_t)); +/* + * Define the input processor state. There's hardly anything here.... + */ +struct pl_process_state_s { + pl_process_proc_t process; + void *process_data; /* closure data for process procedure */ +}; + +#endif /* plparse_INCLUDED */ |