tok822_find.c

[詳解]

/*++
/* NAME
/*  tok822_find 3
/* SUMMARY
/*  token list search operators
/* SYNOPSIS
/*  #include <tok822.h>
/*
/*  TOK822  *tok822_find_type(head, type)
/*  TOK822  *head;
/*  int type;
/*
/*  TOK822  *tok822_rfind_type(tail, type)
/*  TOK822  *tail;
/*  int type;
/* DESCRIPTION
/*  This module implements token list search operations.
/*
/*  tok822_find_type() searches a list of tokens for the first
/*  instance of the specified token type. The result is the
/*  found token or a null pointer when the search failed.
/*
/*  tok822_rfind_type() searches a list of tokens in reverse direction
/*  for the first instance of the specified token type. The result
/*  is the found token or a null pointer when the search failed.
/* 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 <vstring.h>

/* Global library. */

#include <tok822.h>

/* tok822_find_type - find specific token type, forward search */

TOK822 *tok822_find_type(TOK822 *head, int op)
{
    TOK822 *tp;

    for (tp = head; tp != 0 && tp->type != op; tp = tp->next)
     /* void */ ;
    return (tp);
}

/* tok822_rfind_type - find specific token type, backward search */

TOK822 *tok822_rfind_type(TOK822 *tail, int op)
{
    TOK822 *tp;

    for (tp = tail; tp != 0 && tp->type != op; tp = tp->prev)
     /* void */ ;
    return (tp);
}