| 1 | /* Copyright (c) 1985 Ceriel J.H. Jacobs */
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| 2 |
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| 3 | /* $Header: /cvsup/minix/src/commands/yap/machine.h,v 1.1.1.1 2005/04/21 14:55:40 beng Exp $ */
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| 4 |
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| 5 | # ifndef _MACHINE_
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| 6 | # define PUBLIC extern
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| 7 | # else
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| 8 | # define PUBLIC
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| 9 | # endif
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| 10 |
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| 11 | /*
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| 12 | * Simple minded finite state machine implementation to recognize
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| 13 | * strings.
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| 14 | */
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| 15 |
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| 16 | struct state {
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| 17 | char s_char; /* character to match with */
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| 18 | char s_endstate; /* flag, 1 if this state is an endstate */
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| 19 | struct state *s_match; /* new state if matched */
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| 20 | struct state *s_next; /* other characters to match with */
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| 21 | short s_cnt; /* if an endstate, this field is filled with
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| 22 | * some info, dependant on the machine.
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| 23 | */
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| 24 | };
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| 25 |
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| 26 | # define FSM_OKE 0
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| 27 | # define FSM_ISPREFIX -1 /* Must be < 0 */
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| 28 | # define FSM_HASPREFIX 1
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| 29 |
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| 30 | int addstring();
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| 31 | /*
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| 32 | * int addstring(str,cnt,mach)
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| 33 | * char *str; The string to be recognized
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| 34 | * int cnt; Attribute of the string.
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| 35 | * struct state **mach; The finite state machine
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| 36 | *
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| 37 | * This routine adds a string to a finite state automaton.
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| 38 | * It returns FSM_ISPREFIX if the added string is a prefix of a string already
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| 39 | * in the automaton, FSM_HASPREFIX if a string, already recognized by the
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| 40 | * automaton, is a prefix of the added string.
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| 41 | * Otherwise it returns FSM_OKE.
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| 42 | */
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| 43 |
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| 44 | int match();
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| 45 | /*
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| 46 | * int match(str,p_int,mach)
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| 47 | * char *str; pointer to string
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| 48 | * int *p_int; Pointer to an integer
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| 49 | * struct state *mach; The finite state machine
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| 50 | *
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| 51 | * A match of the string indicated by "str" is tried. If a head of "str"
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| 52 | * is recognized by the finite state automaton, a machine dependant number
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| 53 | * is put in the integer pointed to by "p_int".
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| 54 | * The number of characters that match is returned, so a return value of 0
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| 55 | * means no match.
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| 56 | * A return value of FSM_PREFIX means that the string "str" was a prefix of a
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| 57 | * matched string.
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| 58 | */
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| 59 |
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| 60 | # undef PUBLIC
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