#include<u.h>#include<libc.h>#include<json.h> static void*erealloc(void *ptr, ulong sz){	ptr = realloc(ptr, sz);	if(ptr == nil)		sysfatal("realloc: %r");	return ptr;} voidJinit(Jparser *p){	memset(p, 0, sizeof *p);} voidJterm(Jparser *p){	if(p->mtok > 0 || p->tokens != nil)		free(p->tokens);} static Jtok*gettok(Jparser *p){	uint i;		if(p->ntok == p->mtok){		p->mtok = (p->ntok << 1) + 1;		p->tokens = erealloc(p->tokens, p->mtok * sizeof *p->tokens);		for(i = p->ntok; i < p->mtok; i++)			memset(&p->tokens[i], 0, sizeof *p->tokens);	}		return &p->tokens[p->ntok++];} static char *parsestr(Jparser *p, char *s){	Jtok *tok;		tok = gettok(p);	tok->type = JStr;	for(tok->start = ++s; *s != '\0' && utfrune("\"", *s) == nil; s++)		if(utfrune("\\", *s) != nil)			s++;	tok->end = s;	return s;} static char *saccept(char *src, char *str){	while(*src != '\0' && utfrune(str, *src) != nil)		src++;	return src;} static voidincnsub(Jparser *p){	if(p->stktop > 0)		p->tokens[p->tokstk[p->stktop - 1]].nsub++;} intJtokenise(Jparser *p, char *s){	Jtok *tok;	Jtype type;		memset(p->tokens, 0, p->mtok * sizeof *p->tokens);		for(; *s != '\0'; s++){		if(utfrune("\t\r\n ", *s) != nil)			continue;					if(utfrune(":", *s) != nil)			if(p->ntok > 0 && p->tokens[p->ntok - 1].type == JStr)				continue;			else{				werrstr("unexpected :");				return -1;			}				if(utfrune(",", *s) != nil)			if(p->stktop != 0)				continue;			else{				werrstr(", outside of object or array");				return -1;			}				if(utfrune("{[", *s) != nil){			tok = gettok(p);			tok->start = s;			if(p->stktop == JStksz){				werrstr("stack overflow");				return -1;			}			incnsub(p);			p->tokstk[p->stktop++] = p->ntok - 1;			tok->type = utfrune("{", *s) != nil ? JObj:JArr;			continue;		}				if(utfrune("}]", *s) != nil){			type = utfrune("}", *s) != nil ? JObj:JArr;			if(p->ntok == 0)				goto Jmatcherr;			for(tok = &p->tokens[p->ntok - 1]; tok >= p->tokens; tok--){				if(tok->start != nil && tok->end == nil){					if(tok->type != type){						werrstr("expected %c", type == JObj ? '}':']');						return -1;					}					if(p->stktop == 0){						werrstr("stack underflow");						return -1;					}					p->stktop--;					tok->end = s + 1;					goto Jnext;				}			}Jmatcherr:			werrstr("no matching %c", type == JObj ? '{':'[');			return -1;		}				if(utfrune("\"", *s) != nil){			s = parsestr(p, s);			if(*s == '\0' || utfrune("\"", *s) == nil){				werrstr("expected \"");				return -1;			}			incnsub(p);			continue;		}				if(utfrune("tf", *s) != nil){			tok = gettok(p);			tok->type = JBool;			tok->start = s;			s = saccept(s, "truefalse");			tok->end = s--;			incnsub(p);			continue;		}				if(utfrune("n", *s) != nil){			tok = gettok(p);			tok->type = JNil;			tok->start = s;			s = saccept(s, "null");			tok->end = s--;			incnsub(p);			continue;		}				/* Try and parse a number */		tok = gettok(p);		tok->type = JNum;		tok->start = s;		s = saccept(s, "+-");		s = saccept(s, "0123456789");		s = saccept(s, ".");		s = saccept(s, "0123456789");		s = saccept(s, "eE");		s = saccept(s, "+-");		s = saccept(s, "0123456789");		tok->end = s;				if(*s != '\0' && utfrune("\t\r\n }],", *s) == nil){			werrstr("number format error");			return -1;		}				incnsub(p);		s--;Jnext:;	}		if(p->stktop != 0){		werrstr("unexpected end of input");		return -1;	}		return 0;} char *Jtokstr(Jtok *t){	static char *buf;	static ulong sz = 0;	ulong len;	char *src, *dst;		len = t->end - t->start;	if(sz <= len){		sz = len + 1;		buf = erealloc(buf, sz);	}		for(src = t->start, dst = buf; len > 0; len--){		if(*src == '\\')			src++, len--;		*dst++ = *src++;	}	*dst = '\0';	return buf;} uintJnext(Jparser *p, uint i){	int j;	if(i >= p->ntok)		return i;	if(p->tokens[i].type != JObj && p->tokens[i].type != JArr)		return i + 1;	for(j = i; j < p->ntok && p->tokens[i].end > p->tokens[j].start; j++);	return j;} intJfind(Jparser *p, uint r, char *name){	uint i, j;	assert(r < p->ntok);	assert(p->tokens[r].type == JObj);	assert(p->tokens[r].nsub % 2 == 0);		for(i = 0, j = r + 1; i < p->tokens[r].nsub; i += 2){		assert(p->tokens[j].type == JStr);		if(strcmp(Jtokstr(&p->tokens[j]), name) == 0)			return j + 1;		j = Jnext(p, j + 1);	}		if(j >= p->ntok)		return -1;	return j;}