#include <u.h>#include <libc.h>#include <bio.h>#include <xml.h> typedef struct Strtab Strtab;struct Strtab {	int idx;	char *str;	Strtab *left;	Strtab *right;}; static Strtab *Root; static char *look(Strtab *st, int idx){	if(st == nil)		return nil;	if(st->idx < idx)		return look(st->left, idx);	if(st->idx > idx)		return look(st->right, idx);	return st->str;} char *lookstring(int idx){	char *s;	static char buf[16]; 	if((s = look(Root, idx)) == nil){		snprint(buf, sizeof(buf), "<%d>", idx);		return buf;	}	return s;} static voiddumpstr(Strtab *st){	if(st == nil)		return;	dumpstr(st->right);	fprint(2, "%-6d %q\n", st->idx, st->str);	dumpstr(st->left);} voiddumpstrings(void){	dumpstr(Root);}  static Strtab *add(Strtab *st, int idx, char *str){	int n; 	if(st == nil){		st = malloc(sizeof(Strtab));		if(st == nil)			sysfatal("no memory for Strtab\n");		st->idx = idx;		st->str = strdup(str);		if(st->str == nil)			sysfatal("no memory for string\n");		st->left = st->right = nil;		return st;	} 	if(st->idx == idx){		n = strlen(st->str) + strlen(str) + 1;		n += 32;		st->str = realloc(st->str, n);		if(st->str == nil)			sysfatal("no memory for Strtab\n");		strcat(st->str, str);	} 	if(st->idx < idx)		st->left = add(st->left, idx, str);	if(st->idx > idx)		st->right = add(st->right, idx, str);	return st;}  static voidrun(Elem *ep, int idx){	for(; ep; ep = ep->next)		if(strcmp(ep->name, "t") == 0)			if(ep->pcdata)				Root = add(Root, idx, ep->pcdata);			else				Root = add(Root, idx, "");		/* empty string */} voidstringindex(Elem *ep, int idx){	for(; ep; ep = ep->next){		if(strcmp(ep->name, "r") == 0 && ep->child)			run(ep->child, idx);		if(strcmp(ep->name, "t") == 0)			if(ep->pcdata)				Root = add(Root, idx, ep->pcdata);			else				Root = add(Root, idx, "");		/* empty string */	}} voidrd_strings(Elem *ep){	int idx; 	idx = 0;	for(; ep; ep = ep->next)		if(strcmp(ep->name, "si") == 0 && ep->child){			stringindex(ep->child, idx);			idx++;		}}