vs.h

举世闻名的joe记事本源程序

/*
 *	Dynamic string library
 *	Copyright
 *		(C) 1992 Joseph H. Allen
 *
 *	This file is part of JOE (Joe's Own Editor)
 */
#ifndef _JOE_VS_H
#define _JOE_VS_H 1

/***
 *
 * This is a dynamic string library which supports strings which automatically
 * resize themselves when needed.  The strings know their own size, so getting
 * the length of a string is a fast operation and storing zeroes in the
 * strings is permissable.
 *
 * The strings are stored in malloc blocks and have the following format:
 *
 *   <bksize><length><string><zero>
 *
 * 'bksize' and 'length' are ints which give the size of the malloc block
 * and the length of the string.  A zero character always follows the string
 * for compatibility with normal C zero-terminated strings.  The zero is not
 * counted in the string length.
 *
 * To further the compatibility with C strings, the address of a dynamic string
 * is at <string> above, not at <bksize> (whose address is the start of the
 * malloc block).  Thus, dynamic strings can be passed as arguments to UNIX
 * operating system functions and C library function, but they can not be freed
 * with free()- a special function is provided in this library for freeing
 * dynamic strings.
 *
 * The primary dynamic string function is:
 *
 * char *vsncpy(char *d, int off, char *s, int len);
 *                              Copy a block of characters at address 's' of
 *				length 'len' onto the dynamic string 'd' at
 *				offset 'off'.  The dynamic string is expanded
 *				to handle any values of 'len' and 'off' which
 *				might be given.  If 'off' is greater than the
 *				length of the string, SPACEs are placed in the
 *				gap.  If 'd' is NULL, a string is created.  If
 *				'len' is 0, no copying or string expansion
 *				occurs.
 *
 * Three important macros are provided for helping with vsncpy():
 *
 * sc("Hello")   Gives -->  "Hello",sizeof("Hello")-1
 * sz(s)         Gives -->  s,strlen(s)
 * sv(d)         Gives -->  d,sLEN(d)
 *
 * These are used to build arguments for vsncpy().  Many functions
 * can be created with combinations of sc/sz/sv with vsncpy:
 *
 *    s=vsncpy(NULL,0,NULL,0);		Create an empty dynamic string
 *
 *    s=vsncpy(NULL,0,sc("Hello"));	Create a dynamic string initialized
 *					with "Hello"
 *
 *    d=vsncpy(NULL,0,sv(s));		Duplicate a dynamic string
 *
 *    d=vsncpy(NULL,0,sz(s));		Convert a C string into a dynamic
 *                                      string.
 *
 *    d=vsncpy(sv(d),sv(s));		Append dynamic string s onto d.
 *
 *    d=vsncpy(sv(d),sc(".c"));		Append a ".c" extension to d.
 *
 *
 * These lesser functions are also provided:
 *
 * void vsrm(char *s);		Free a string.  Do nothing if 's' is NULL.
 *
 * int sLEN(char *s);		Return the length of the string 's'.  If 's'
 *				is NULL, return 0.
 *
 * char *vstrunc(char *d,int len);
 *				Set the length of a string.  Expand the string
 *				with blanks if necessary.
 *
 * char *vsensure(char *d,int len);
 *				Expand the malloc block for the string if
 *				necessary so that a string of 'len' chars can
 *				fit in it.
 *
 * sLen(s)=10;			Set the length indicator of the string to 10.
 *
 * char *vsins(char *d,int off,int len);
 *				Insert a gap into a string.
 *
 * char *vsdel(char *d,int off,int len);
 *				Delete characters from a string.
 *
 * Other function are provided as well.  Look through the rest of the header
 * file.  The header file is kind of weird looking because it is intended to
 * handle dynamic arrays of any type with only a few changes.
 */

/* Functions and global variable you have to define.  Replace these with
 * macros or defines here if they are not to be actual functions 
 */

/* An element with name 'a' */
typedef unsigned char sELEMENT;

/* Duplicate an element */
/* sELEMENT sdup(); */
#define sdup(a) (a)

/* Delete an element */
/* sELEMENT sdel(); */
#define sdel(a) do {} while(0)		/* effectively do nothing ;-) */

/* Compare a single element */
/* int scmp(); */
#define scmp(a, b) ((a) > (b) ? 1 : ((a) == (b) ? 0 : -1))

/* Compare a single element- case insensitive */
int sicmp(unsigned char a, unsigned char b);

/* A blank element */
/* extern sELEMENT sblank; */
#define sblank ' '

/* A termination element */
/* extern sELEMENT sterm; */
#define sterm '\0'

/************************/
/* Creation/Destruction */
/************************/

/* sELEMENT *vsmk(int len);
 * Create a variable length array.  Space for 'len' elements is preallocated.
 */
sELEMENT *vsmk PARAMS((int len));

/* void vsrm(sELEMENT *vary);
 * Free an array and everything which is in it.  Does nothing if 'vary' is
 * 0.
 */
void vsrm PARAMS((sELEMENT *vary));

/********************/
/* Space management */
/********************/

/* int sSIZ(sELEMENT *vary);
 * int sSiz(sELEMENT *vary);
 * Access size part of array.  This int indicates the number of elements which
 * can fit in the array before realloc needs to be called.  It does not include
 * the extra space needed for the terminator and the header.
 *
 * sSIZ returns 0 if you pass it 0.  sSiz does not do this checking,
 * but can be used as an lvalue.
 */
#define sSIZ(a) ((a) ? *((int *)(a) - 2) : 0)
#define sSiz(a) (*((int *)(a) - 2))

/* int sLEN(sELEMENT *vary);
 * int sLen(sELEMENT *vary);
 * Access length part of array.  This int indicates the number of elements
 * currently in the array (not including the terminator).  This should be
 * used primarily for reading the size of the array.  It can be used for
 * setting the size of the array, but it must be used with care since it
 * does not eliminate elements (if the size decreases) or make sure there's
 * enough room (if the size increases).  See vensure and vtrunc.
 *
 * sLEN return a length of zero if 'vary' is 0.
 * sLen doesn't do this checking, but can be used as an lvalue
 */
#define sLEN(a) ((a) ? *((int *)(a) - 1) : 0)
#define sLen(a) (*((int *)(a) - 1))

/* int slen(sELEMENT *ary);
 * Compute length of char or variable length array by searching for termination
 * element.  Returns 0 if 'vary' is 0.
 */
int slen PARAMS((sELEMENT *ary));

/* sELEMENT *vsensure(sELEMENT *vary, int len);
 * Make sure there's enough space in the array for 'len' elements.  Whenever
 * vsensure reallocs the array, it allocates 25% more than the necessary
 * minimum space in anticipation of future expansion.  If 'vary' is 0,
 * it creates a new array.
 */
sELEMENT *vsensure PARAMS((sELEMENT *vary, int len));

/* sELEMENT *vstrunc(sELEMENT *vary, int len));
 * Truncate array to indicated size.  This zaps or expands with blank elements
 * and sets the LEN() of the array.  A new array is created if 'vary' is 0.
 */
sELEMENT *vstrunc PARAMS((sELEMENT *vary, int len));

/************************************/
/* Function which write to an array */
/************************************/

/* sELEMENT *vsfill(sELEMENT *vary, int pos, sELEMENT el, int len);
 * Set 'len' element of 'vary' beginning at 'pos' to duplications of 'el'.
 * Ok, if pos/len are past end of array.  If 'vary' is 0, a new array is
 * created.
 *
 * This does not zap previous values.  If you need that to happen, call
 * vszap first.  It does move the terminator around properly though.
 */
sELEMENT *vsfill PARAMS((sELEMENT *vary, int pos, sELEMENT el, int len));

/* sELEMENT *vsncpy(sELEMENT *vary, int pos, sELEMENT *array, int len));
 * Copy 'len' elements from 'array' onto 'vary' beginning at position 'pos'.
 * 'array' can be a normal char array since the length is passed seperately.  The
 * elements are copied, not duplicated.  A new array is created if 'vary' is
 * 0.  This does not zap previous elements.
 */
sELEMENT *vsncpy PARAMS((sELEMENT *vary, int pos, sELEMENT *array, int len));

/* sELEMENT *vsndup(sELEMENT *vary, int pos, sELEMENT *array, int len));
 * Duplicate 'len' elements from 'array' onto 'vary' beginning at position
 * 'pos'.  'array' can be a char array since its length is passed seperately.  A
 * new array is created if 'vary' is 0.
 */