NetBSD/gnu/dist/postfix/global/tok822_tree.c

308 lines
7.0 KiB
C

/*++
/* NAME
/* tok822_tree 3
/* SUMMARY
/* assorted token tree operators
/* SYNOPSIS
/* #include <tok822.h>
/*
/* TOK822 *tok822_append(t1, t2)
/* TOK822 *t1;
/* TOK822 *t2;
/*
/* TOK822 *tok822_prepend(t1, t2)
/* TOK822 *t1;
/* TOK822 *t2;
/*
/* TOK822 *tok822_cut_before(tp)
/* TOK822 *tp;
/*
/* TOK822 *tok822_cut_after(tp)
/* TOK822 *tp;
/*
/* TOK822 *tok822_unlink(tp)
/* TOK822 *tp;
/*
/* TOK822 *tok822_sub_append(t1, t2)
/* TOK822 *t1;
/*
/* TOK822 *tok822_sub_prepend(t1, t2)
/* TOK822 *t1;
/* TOK822 *t2;
/*
/* TOK822 *tok822_sub_keep_before(t1, t2)
/* TOK822 *tp;
/*
/* TOK822 *tok822_sub_keep_after(t1, t2)
/* TOK822 *tp;
/*
/* int tok822_apply(list, type, action)
/* TOK822 *list;
/* int type;
/* int (*action)(TOK822 *token);
/*
/* int tok822_grep(list, type)
/* TOK822 *list;
/* int type;
/*
/* TOK822 *tok822_free_tree(tp)
/* TOK822 *tp;
/* DESCRIPTION
/* This module manipulates trees of token structures. Trees grow
/* to the right or downwards. Operators are provided to cut and
/* combine trees in various manners.
/*
/* tok822_append() appends the token list \fIt2\fR to the right
/* of token list \fIt1\fR. The result is the last token in \fIt2\fR.
/* The appended list inherits the \fIowner\fR attribute from \fIt1\fR.
/* The parent node, if any, is not updated.
/*
/* tok822_prepend() inserts the token list \fIt2\fR to the left
/* of token \fIt1\fR. The result is the last token in \fIt2\fR.
/* The appended list inherits the \fIowner\fR attribute from \fIt1\fR.
/* The parent node, if any, is not updated.
/*
/* tok822_cut_before() breaks a token list on the left side of \fItp\fR
/* and returns the left neighbor of \tItp\fR.
/*
/* tok822_cut_after() breaks a token list on the right side of \fItp\fR
/* and returns the right neighbor of \tItp\fR.
/*
/* tok822_unlink() disconnects a token from its left and right neighbors
/* and returns the left neighbor of \tItp\fR.
/*
/* tok822_sub_append() appends the token list \fIt2\fR to the right
/* of the token list below \fIt1\fR. The result is the last token
/* in \fIt2\fR.
/*
/* tok822_sub_prepend() prepends the token list \fIt2\fR to the left
/* of the token list below \fIt1\fR. The result is the last token
/* in \fIt2\fR.
/*
/* tok822_sub_keep_before() keeps the token list below \fIt1\fR on the
/* left side of \fIt2\fR and returns the tail of the disconnected list.
/*
/* tok822_sub_keep_after() keeps the token list below \fIt1\fR on the
/* right side of \fIt2\fR and returns the head of the disconnected list.
/*
/* tok822_apply() applies the specified action routine to all tokens
/* matching the given type (to all tokens when a null type is given).
/* Processing terminates when the action routine returns a non-zero
/* value. The result is the last result returned by the action routine.
/* tok822_apply() does not traverse vertical links.
/*
/* tok822_grep() returns a null-terminated array of pointers to tokens
/* matching the specified type (all tokens when a null type is given).
/* tok822_grep() does not traverse vertical links. The result must be
/* given to myfree().
/*
/* tok822_free_tree() destroys a tree of token structures and
/* conveniently returns a null pointer.
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*--*/
/* System library. */
#include <sys_defs.h>
/* Utility library. */
#include <mymalloc.h>
#include <vstring.h>
/* Global library. */
#include "tok822.h"
/* tok822_append - insert token list, return end of inserted list */
TOK822 *tok822_append(TOK822 *t1, TOK822 *t2)
{
TOK822 *next = t1->next;
t1->next = t2;
t2->prev = t1;
t2->owner = t1->owner;
while (t2->next)
(t2 = t2->next)->owner = t1->owner;
t2->next = next;
if (next)
next->prev = t2;
return (t2);
}
/* tok822_prepend - insert token list, return end of inserted list */
TOK822 *tok822_prepend(TOK822 *t1, TOK822 *t2)
{
TOK822 *prev = t1->prev;
if (prev)
prev->next = t2;
t2->prev = prev;
t2->owner = t1->owner;
while (t2->next)
(t2 = t2->next)->owner = t1->owner;
t2->next = t1;
t1->prev = t2;
return (t2);
}
/* tok822_cut_before - split list before token, return predecessor token */
TOK822 *tok822_cut_before(TOK822 *tp)
{
TOK822 *prev = tp->prev;
if (prev) {
prev->next = 0;
tp->prev = 0;
}
return (prev);
}
/* tok822_cut_after - split list after token, return successor token */
TOK822 *tok822_cut_after(TOK822 *tp)
{
TOK822 *next = tp->next;
if (next) {
next->prev = 0;
tp->next = 0;
}
return (next);
}
/* tok822_unlink - take token away from list, return predecessor token */
TOK822 *tok822_unlink(TOK822 *tp)
{
TOK822 *prev = tp->prev;
TOK822 *next = tp->next;
if (prev)
prev->next = next;
if (next)
next->prev = prev;
tp->prev = tp->next = 0;
return (prev);
}
/* tok822_sub_append - append sublist, return end of appended list */
TOK822 *tok822_sub_append(TOK822 *t1, TOK822 *t2)
{
if (t1->head) {
return (t1->tail = tok822_append(t1->tail, t2));
} else {
t1->head = t2;
while (t2->next)
(t2 = t2->next)->owner = t1;
return (t1->tail = t2);
}
}
/* tok822_sub_prepend - prepend sublist, return end of prepended list */
TOK822 *tok822_sub_prepend(TOK822 *t1, TOK822 *t2)
{
TOK822 *tp;
if (t1->head) {
tp = tok822_prepend(t1->head, t2);
t1->head = t2;
return (tp);
} else {
t1->head = t2;
while (t2->next)
(t2 = t2->next)->owner = t1;
return (t1->tail = t2);
}
}
/* tok822_sub_keep_before - cut sublist, return tail of disconnected list */
TOK822 *tok822_sub_keep_before(TOK822 *t1, TOK822 *t2)
{
TOK822 *tail = t1->tail;
if ((t1->tail = tok822_cut_before(t2)) == 0)
t1->head = 0;
return (tail);
}
/* tok822_sub_keep_after - cut sublist, return head of disconnected list */
TOK822 *tok822_sub_keep_after(TOK822 *t1, TOK822 *t2)
{
TOK822 *head = t1->head;
if ((t1->head = tok822_cut_after(t2)) == 0)
t1->tail = 0;
return (head);
}
/* tok822_free_tree - destroy token tree */
TOK822 *tok822_free_tree(TOK822 *tp)
{
if (tp) {
if (tp->next)
tok822_free_tree(tp->next);
if (tp->head)
tok822_free_tree(tp->head);
tok822_free(tp);
}
return (0);
}
/* tok822_apply - apply action to specified tokens */
int tok822_apply(TOK822 *tree, int type, TOK822_ACTION action)
{
TOK822 *tp;
int result = 0;
for (tp = tree; tp; tp = tp->next) {
if (type == 0 || tp->type == type)
if ((result = action(tp)) != 0)
break;
}
return (result);
}
/* tok822_grep - list matching tokens */
TOK822 **tok822_grep(TOK822 *tree, int type)
{
TOK822 **list;
TOK822 *tp;
int count;
for (count = 0, tp = tree; tp; tp = tp->next)
if (type == 0 || tp->type == type)
count++;
list = (TOK822 **) mymalloc(sizeof(*list) * (count + 1));
for (count = 0, tp = tree; tp; tp = tp->next)
if (type == 0 || tp->type == type)
list[count++] = tp;
list[count] = 0;
return (list);
}