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bnflite.h
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bnflite.h
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/*************************************************************************\
* BNF Lite is a C++ template library for lightweight grammar parsers *
* Copyright (c) 2017 by Alexander A. Semjonov. ALL RIGHTS RESERVED. *
* *
* Permission is hereby granted, free of charge, to any person *
* obtaining a copy of this software and associated documentation *
* files (the "Software"), to deal in the Software without restriction, *
* including without limitation the rights to use, copy, modify, merge, *
* publish, distribute, sublicense, and/or sell copies of the Software, *
* and to permit persons to whom the Software is furnished to do so, *
* subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be *
* included in all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, *
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY *
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, *
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH *
* THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
\*************************************************************************/
#ifndef BNFLITE_H
#define BNFLITE_H
#include <string.h>
#include <string>
#include <list>
#include <vector>
#include <bitset>
#include <map>
#include <algorithm>
#include <typeinfo>
namespace bnf
{
// BNF (Backus-Naur form) is a notation for describing syntax of computer languages
// BNF Lite is the source code template library implementing the way to support BNF specifications
// BNF Terms:
// * Production rule is formal BNF expression which is a conjunction of a series
// of more concrete rules:
// production_rule ::= <rule_1>...<rule_n> | <rule_n_1>...<rule_m>;
// * e.g.
// <digit> ::= <0> | <1> | <2> | <3> | <4> | <5> | <6> | <7> | <8> | <9>
// <number> ::= <digit> | <digit> <number>
// where the number is just a digit or another number with one more digit;
// Now this example can be presented in C++ friendly notation:
// Lexem Digit = Token("0") | "1" | "2" | "4" | "5" | "6" | "7" | "8" | "9";
// RULE(Number) = Digit | Digit + Number;
// where:
// * Token is a terminal production;
// * Lexem (or LEXEM) is a lexical production;
// * Rule (or RULE) is used here as synonym of syntax production
// To parse any number (e.g. 532) it is just enough to call the bnf::Analyze(Number, "532")
enum Limits { maxCharNum = 256, maxLexemLength = 1024, maxRepeate = 4096, maxEmptyStack = 16
};
enum Status { eNone = 0, eOk = 1,
eRet = 0x8, e1st = 0x10, eSkip = 0x20, eTry = 0x40, eNull = 0x80,
eRest = 0x0100, eNoData = 0x0200, eOver = 0x0400, eEof = 0x0800,
eBadRule = 0x1000, eBadLexem = 0x2000, eSyntax = 0x4000,
eError = ((~(unsigned int)0) >> 1) + 1
};
class _Tie; class _And; class _Or; class _Cycle;
/* context class to support the first kind of callback */
class _Base // base parser class
{
public:
std::vector<const char*> cntxV; // public for internal extensions
protected: friend class Token; friend class Lexem; friend class Rule;
friend class _And; friend class _Or; friend class _Cycle;
int level;
const char* pstop;
int _chk_stack()
{ static const char* org; static int cnt;
if (org != cntxV.back()) { org = cntxV.back(); cnt = 0; }
else if (++cnt > maxEmptyStack) return eOver|eError;
return 0; }
const char* (*zero_parse)(const char*);
int catch_error(const char* ptr) // attempt to catch general syntax error
{ return eSyntax|eError; }
virtual void _erase(int low, int up = 0)
{ cntxV.erase(cntxV.begin() + low, up? cntxV.begin() + up : cntxV.end() ); }
virtual std::pair<void*, int> _pre_call(void* callback)
{ return std::make_pair((void*)0, 0); }
virtual void _post_call(std::pair<void*, int> up)
{};
virtual void _do_call(std::pair<void*, int> up, void* callback, size_t org, const char* name)
{};
virtual void _stub_call(size_t org, const char* name)
{};
public:
int _analyze(_Tie& root, const char* text, size_t*);
_Base(const char* (*pre)(const char*)) : level(1), pstop(0), zero_parse(pre?pre:base_parser)
{};
virtual ~_Base()
{};
// default pre-parser procedure to skip special symbols
static const char* base_parser(const char* ptr)
{ for (char cc = *ptr; cc != 0; cc = *++ptr) {
if (cc != ' ' && cc !='\t' && cc != '\n' && cc != '\r') {
break; } }
return ptr; }
};
#if !defined(_MSC_VER)
#define _NAME_OFF 0
#else
#define _NAME_OFF 6
#endif
/* internal base class to support multiform relationships between different BNFlite elements */
class _Tie
{
bool _is_compound();
protected: friend class _Base; friend class ExtParser;
friend class _And; friend class _Or; friend class _Cycle;
friend class Token; friend class Lexem; friend class Rule;
bool inner;
mutable std::vector<const _Tie*> use;
mutable std::list<const _Tie*> usage;
std::string name;
template<class T> static void _setname(T* t, const char * name = 0)
{ static int cnt = 0;
if (name) { t->name = name; }
else { t->name = typeid(*t).name() + _NAME_OFF;
for (int i = ++cnt; i != 0; i /= 10) {
t->name += '0' + i - (i/10)*10; } } }
void _clone(const _Tie* lnk)
{ usage.swap(lnk->usage);
for (std::list<const _Tie*>::const_iterator usg = usage.begin(); usg != usage.end(); ++usg) {
for (size_t i = 0; i < (*usg)->use.size(); i++) {
if ((*usg)->use[i] == lnk) {
(*usg)->use[i] = this; } } }
use.swap(lnk->use);
for (size_t i = 0; i < use.size(); i++) {
if (!use[i]) continue;
std::list<const _Tie*>::iterator itr =
std::find(use[i]->usage.begin(), use[i]->usage.end(), lnk);
*itr = this; }
if(lnk->inner) {
delete lnk; } }
_Tie(std::string nm = "") :inner(false), name(nm)
{};
explicit _Tie(const _Tie* lnk) : inner(true), name(lnk->name)
{ _clone(lnk); }
_Tie(const _Tie& link) : inner(link.inner), name(link.name)
{ _clone(&link); }
virtual ~_Tie()
{ for (size_t i = 0; i < use.size(); i++) {
const _Tie* lnk = use[i];
if (lnk) {
lnk->usage.remove(this);
for (size_t j = 0; j < use.size(); j++) {
if ( use[j] == lnk) {
use[j] = 0; } }
if (lnk->inner && lnk->usage.size() == 0) {
delete lnk; } } } }
static int call_1st(const _Tie* lnk, _Base* parser)
{ return lnk->_parse(parser); }
void _clue(const _Tie& link)
{ if (!use.size() || _is_compound()) {
use.push_back(&link);
} else {
if (use[0]) {
use[0]->usage.remove(this);
if (use[0]->inner && use[0]->usage.size() == 0) {
delete use[0]; } }
use[0] = &link; }
link.usage.push_back(this); }
template<class T> static T* _safe_delete(T* t)
{ if (t->usage.size() != 0) {
if (!t->inner) {
return new T(t); } }
return 0; }
virtual int _parse(_Base* parser) const throw() = 0;
public:
void setName(const char * name)
{ this->name = name; }
const char *getName()
{ return name.c_str(); }
_And operator+(const _Tie& link);
_And operator+(const char* s);
_And operator+(bool (*f)(const char*, size_t));
friend _And operator+(const char* s, const _Tie& lnk);
friend _And operator+(bool (*f)(const char*, size_t),const _Tie& lnk);
_Or operator|(const _Tie& link);
_Or operator|(const char* s);
_Or operator|(bool (*f)(const char*, size_t));
friend _Or operator|(const char* s, const _Tie& lnk);
friend _Or operator|(bool (*f)(const char*, size_t), const _Tie& lnk);
// Support Augmented BNF constructions like "<a>*<b><element>" to implement repetition;
// In ABNF <a> and <b> imply at least <a> and at most <b> occurrences of the element;
// e.g *<element> allows any number(from 0 to infinity, 1*<element> requires at least one;
// 3*3<element> allows exactly 3 and 1*2<element> allows one or two.
_Cycle operator()(int at_least, int total); // ABNF case <a>.<b>*<element> as element(a,b)
_Cycle operator*(); // ABNF case *<element> (from 0 to infinity)
_Cycle operator!(); // ABNF case <0>.<1>*<element> or <1><element> (at least one)
};
/* implementation of parsing control rules */
template <const unsigned int flg, const char cc> class _Ctrl: public _Tie
{
protected: friend class _Tie;
virtual int _parse(_Base* parser) const throw()
{ return flg; }
explicit _Ctrl(const _Ctrl* ctrl) :_Tie(ctrl)
{};
_Ctrl(const _Ctrl& control) :_Tie(control)
{};
public:
explicit _Ctrl(): _Tie(std::string(1, cc))
{};
~_Ctrl()
{ _safe_delete(this); }
};
/* Null operation, immediate successful return */
typedef _Ctrl<eOk, 'N'> Null; // stub for some constructions (e.g. "zero-or-one")
/* Force Return, immediate return from conjunction rule to impact disjunction rule */
typedef _Ctrl<eOk|eRet, 'R'> Return;
/* Switch to use "Accept First" strategy for disjunction rule instead "Accept Best" */
typedef _Ctrl<e1st, '1'> AcceptFirst;
/* Try to catch syntax error in current conjunction rule */
typedef _Ctrl<eOk|eTry, 'T'> Try;
/* Check but do not accept next statement for conjunction rule */
typedef _Ctrl<eOk|eSkip, 'S'> Skip;
/* Force syntax error */
typedef _Ctrl<eError|eSyntax, 'E'> Catch;
/* interface class for tokens */
class Token: public _Tie
{
Token& operator=(const _Tie&);
explicit Token(const _Tie&);
public:
class interval_set : protected std::map<wchar_t,bool>
{
public:
interval_set()
{ insert(std::make_pair(0, false)); insert(std::make_pair(WCHAR_MAX, false)); }
bool test(wchar_t key) const
{ return (--upper_bound(key))->second; }
void reset(wchar_t key)
{ set(key, 0, false); }
void set(wchar_t key, size_t rep = 0, bool val = true)
{ wchar_t key_end = key + rep + 1;
if (key == 0 || key_end == WCHAR_MAX) return;
std::map<wchar_t,bool>::iterator right_begin = lower_bound(key);
std::map<wchar_t,bool>::iterator left_begin = right_begin; --left_begin;
std::map<wchar_t,bool>::iterator right_end = upper_bound(key_end);
std::map<wchar_t,bool>::iterator left_end = right_end; --left_end;
if (left_end->second == val)
if (left_end->first >= key_end && right_begin == left_end) erase(right_begin);
else erase(right_begin, right_end);
else {
std::map<wchar_t,bool>::iterator itr = insert(std::make_pair(key_end, left_end->second)).first;
if(right_begin->first < itr->first)
erase(right_begin, itr); }
if (left_begin->second != val)
insert(std::make_pair(key, val)); }
void flip()
{ for (std::map<wchar_t, bool>::iterator itr = begin(); itr != end(); ++itr)
itr->second = !itr->second; }
};
protected: friend class _Tie;
#if defined(BNFLITE_WIDE)
interval_set match;
#else
std::bitset<bnf::maxCharNum> match;
#endif
explicit Token(const Token* tkn) :_Tie(tkn), match(tkn->match)
{};
virtual int _parse(_Base* parser) const throw()
{ const char* cc = parser->cntxV.back();
if (parser->level)
cc = parser->zero_parse(cc);
char c = *((unsigned char*)cc);
if (match.test(c)) {
if (parser->level) {
parser->cntxV.push_back(cc);
parser->_stub_call(parser->cntxV.size() - 1, name.c_str()); }
parser->cntxV.push_back(++cc);
return c ? eOk : eOk|eEof; }
return c ? eNone : eEof; }
public:
Token(const char c) :_Tie(std::string(1, c))
{ Add(c, 0); }; // create single char token
Token(int fst, int lst) :_Tie(std::string(1, fst).append("-") += lst)
{ Add(fst, lst); }; // create token by ASCII charactes in range
Token(const char *s) :_Tie(std::string(s))
{ Add(s); }; // create token by C string sample
Token(const char *s, const Token& token) :_Tie(std::string(s)), match(token.match)
{ Add(s); }; // create token by both C string sample and another token set
Token(const Token& token) :_Tie(token), match(token.match)
{};
virtual ~Token()
{ _safe_delete(this); }
void Add(int fst, int lst = 0, const char *sample = "") // add characters in range fst...lst exept mentioned in sample;
{ switch (lst) { // lst == 0|1: add single | upper&lower case character(s)
case 1: if (fst >= 'A' && fst <= 'Z') match.set(fst - 'A' + 'a');
else if (fst >= 'a' && fst <= 'z') match.set(fst - 'a' + 'A');
case 0: match.set((unsigned char)fst); break;
default: for (int i = fst; i <= lst; i++) {
match.set((unsigned char)i); }
Remove(sample); } }
void Add(const char *sample)
{ while (*sample) {
match.set((unsigned char)*sample++); } }
void Remove(int fst, int lst = 0)
{ for (int i = fst; i <= (lst?lst:fst); i++) {
match.reset((unsigned char)i); } }
void Remove(const char *sample)
{ while (*sample) {
match.reset((unsigned char)*sample++); } }
int GetSymbol(int next = 1) // get first short symbol
{ for (unsigned int i = next; i < maxCharNum; i++) {
if (match.test(i)) return i; }
return 0; }
Token& Invert() // invert token to build construction to not match
{ match.flip(); return *this; }
};
#if __cplusplus > 199711L
inline Token operator""_T(const char* sample, size_t len)
{ return Token(std::string(sample, len).c_str()); }
#endif
/* standalone callback wrapper class */
class Action: public _Tie
{
bool (*action)(const char* lexem, size_t len);
Action(_Tie&);
protected: friend class _Tie;
explicit Action(const Action* a) :_Tie(a), action(a->action)
{};
int _parse(_Base* parser) const throw()
{ std::vector<const char*>::reverse_iterator itr = parser->cntxV.rbegin() + 1;
return (*action)(*itr, parser->cntxV.back() - *itr); }
public:
Action(bool (*action)(const char* lexem, size_t len), const char *name = "")
:_Tie(name), action(action) {};
virtual ~Action()
{ _safe_delete(this); }
};
/* internal class to support conjunction constructions of BNFlite elements */
class _And: public _Tie
{
protected: friend class _Tie; friend class Lexem;
_And(const _Tie& b1, const _Tie& b2):_Tie("")
{ (name = b1.name).append("+") += b2.name; _clue(b1); _clue(b2); }
explicit _And(const _And* rl) :_Tie(rl)
{};
virtual int _parse(_Base* parser) const throw()
{ int stat = 0; size_t save = 0; size_t size = parser->cntxV.size();
for (unsigned i = 0; i < use.size(); i++, stat &= ~(eSkip|eOk)) {
stat |= use[i]->_parse(parser);
if (!(stat & eOk) || (stat & eError) || ((stat & eEof) && (parser->cntxV.back() == parser->cntxV[size - 1]))) {
if (parser->level && (stat & eTry) && !(stat & eError) && !save) {
stat |= parser->catch_error(parser->cntxV.back()); }
parser->_erase(size);
return stat & ~(eTry|eSkip|eOk); }
else {
if (save) {
parser->cntxV.resize(save);
save = 0; }
if (stat & eSkip) {
save = parser->cntxV.size(); } } }
return eOk | (stat & ~(eTry|eSkip)); }
public:
~_And()
{ _safe_delete(this); }
_And& operator+(const _Tie& rule2)
{ name.append("+") += rule2.name; _clue(rule2); return *this; }
_And& operator+(const char* s)
{ name.append("+") += s; _clue(Token(s)); return *this; }
_And& operator+(bool (*f)(const char*, size_t))
{ name += "+()"; _clue(Action(f)); return *this; }
friend _And operator+(const char* s, const _Tie& link);
friend _And operator+(bool (*f)(const char*, size_t), const _Tie& link);
};
inline _And _Tie::operator+(const _Tie& rule2)
{ return _And(*this, rule2); }
inline _And _Tie::operator+(const char* s)
{ return _And(*this, Token(s)); }
inline _And _Tie::operator+(bool (*f)(const char*, size_t))
{ return _And(*this, Action(f)); }
inline _And operator+(const char* s, const _Tie& link)
{ return _And(Token(s), link); }
inline _And operator+(bool (*f)(const char*, size_t), const _Tie& link)
{ return _And(Action(f), link); }
/* internal class to support disjunction constructions of BNFlite elements */
class _Or: public _Tie
{
protected: friend class _Tie;
_Or(const _Tie& b1, const _Tie& b2):_Tie("")
{ (name = b1.name).append("|") += b2.name; _clue(b1); _clue(b2); }
explicit _Or(const _Or* rl) :_Tie(rl)
{};
virtual int _parse(_Base* parser) const throw()
{ int stat = 0; int tstat = 0; int max = 0; int tmp = -1;
size_t size = parser->cntxV.size();
for (unsigned i = 0; i < use.size(); i++, stat &= ~(eOk|eRet|eEof|eError)) {
size_t msize = parser->cntxV.size();
if (msize > size) {
parser->cntxV.push_back(parser->cntxV[size - 1]); }
stat |= use[i]->_parse(parser);
if (stat & (eOk|eError)) {
tmp = parser->cntxV.back() - parser->cntxV[size - 1];
if ((tmp > max) || (tmp > 0 && (stat & (eRet|e1st))) || (tmp >= 0 && (stat & eError))) {
max = tmp;
tstat = stat;
if (msize > size) {
parser->_erase(size, msize + 1); }
if (stat & (eRet|e1st|eError)) {
break; }
continue; } }
if (parser->cntxV.size() > msize) {
parser->_erase(msize); } }
return (max || tmp >= 0 ? tstat | eOk: tstat & ~eOk) & ~(e1st|eRet); }
public:
~_Or()
{ _safe_delete(this); }
_Or& operator|(const _Tie& rule2)
{ name.append("|") += rule2.name; _clue(rule2); return *this; }
_Or& operator|(const char* s)
{ name.append("|") += s; _clue(Token(s)); return *this; }
_Or& operator|(bool (*f)(const char*, size_t))
{ name += "|()"; _clue(Action(f)); return *this; }
friend _Or operator|(const char* s, const _Tie& link);
friend _Or operator|(bool (*f)(const char*, size_t), const _Tie& link);
};
inline _Or _Tie::operator|(const _Tie& rule2)
{ return _Or(*this, rule2); }
inline _Or _Tie::operator|(const char* s)
{ return _Or(*this, Token(s)); }
inline _Or _Tie::operator|(bool (*f)(const char*, size_t))
{ return _Or(*this, Action(f)); }
inline _Or operator|(const char* s, const _Tie& link)
{ return _Or(Token(s), link); }
inline _Or operator|(bool (*f)(const char*, size_t), const _Tie& link)
{ return _Or(Action(f), link); }
inline bool _Tie::_is_compound()
{ return dynamic_cast<_And*>(this) || dynamic_cast<_Or*>(this); }
/* interface class for lexem */
class Lexem: public _Tie
{
Lexem& operator=(const class Rule&);
Lexem(const Rule& rule);
protected: friend class _Tie;
explicit Lexem(Lexem* lxm) :_Tie(lxm)
{};
virtual int _parse(_Base* parser) const throw()
{ if (!use.size())
return eError|eBadLexem;
if (!parser->level || dynamic_cast<const Action*>(use[0]))
return use[0]->_parse(parser);
size_t size = parser->cntxV.size();
parser->cntxV.push_back(parser->zero_parse(parser->cntxV.back()));
parser->level--;
int stat = use[0]->_parse(parser);
parser->level++;
if ((stat & eOk) && parser->cntxV.size() - size > 1) {
parser->_stub_call(size - 1, name.c_str());
if (parser->cntxV.back() > parser->pstop) parser->pstop = parser->cntxV.back();
parser->cntxV[(++size)++] = parser->cntxV.back(); }
parser->cntxV.resize(size);
return stat; }
public:
Lexem(const char *literal, bool cs = 0) :_Tie()
{ int size = strlen(literal);
switch (size) {
case 1: this->operator=(Token(literal[0], cs));
case 0: break;
default: {
_And _and(Token(literal[0], cs), Token(literal[1], cs));
for (int i = 2; i < size; i++) {
_and.operator+((const _Tie&)Token(literal[i], cs)); }
this->operator=(_and); } }
_setname(this, literal); }
explicit Lexem() :_Tie()
{ _setname(this); }
virtual ~Lexem()
{ _safe_delete(this); }
Lexem(const _Tie& link) :_Tie()
{ _setname(this, 0); _clue(link); }
Lexem& operator=(const Lexem& lexem)
{ if (&lexem != this) _clue(lexem);
return *this; }
Lexem& operator=(const _Tie& link)
{ _clue(link); return *this; }
};
/* interface class for BNF rules */
class Rule : public _Tie
{
void* callback;
protected: friend class _Tie; friend class _And;
explicit Rule(const Rule* rl) :_Tie(rl), callback(rl->callback)
{};
virtual int _parse(_Base* parser) const throw()
{ if (!use.size() || !parser->level)
return eError|eBadRule;
if (dynamic_cast<const Action*>(use[0])) {
return use[0]->_parse(parser); }
size_t size = parser->cntxV.size();
std::pair<void*, int> up = parser->_pre_call(callback);
int stat = use[0]->_parse(parser);
if ((stat & eOk) && parser->cntxV.size() - size > 1) {
parser->_do_call(up, callback, size, name.c_str());
if (parser->cntxV.back() > parser->pstop) parser->pstop = parser->cntxV.back();
parser->cntxV[(++size)++] = parser->cntxV.back(); }
parser->cntxV.resize(size);
parser->_post_call(up);
return stat; }
public:
explicit Rule() :_Tie(), callback(0)
{ _setname(this); }
virtual ~Rule()
{ _safe_delete(this); }
Rule(const _Tie& link) :_Tie(), callback(0)
{ const Rule* rl = dynamic_cast<const Rule*>(&link);
if (rl) { _clone(&link); callback = rl->callback; name = rl->name; }
else { _clue(link); callback = 0; _setname(this); } }
Rule& operator=(const _Tie& link)
{ _clue(link); return *this; }
Rule& operator=(const Rule& rule)
{ if (&rule == this) return *this;
return this->operator=((const _Tie&)rule); }
template <class U> friend Rule& Bind(Rule& rule, U (*callback)(std::vector<U>&));
template <class U> Rule& operator[](U (*callback)(std::vector<U>&));
};
/* friendly debug interface */
#define LEXEM(lexem) Lexem lexem; lexem.setName(#lexem); lexem
#define RULE(rule) Rule rule; rule.setName(#rule); rule
/* internal class to support repeat constructions of BNF elements */
class _Cycle: public _Tie
{
unsigned int min, max;
int flag;
protected: friend class _Tie;
explicit _Cycle(const _Cycle* u) :_Tie(u), min(u->min), max(u->max), flag(u->flag)
{};
_Cycle(const _Cycle& w) :_Tie(w), min(w.min), max(w.max), flag(w.flag)
{};
int _parse(_Base* parser) const throw()
{ int stat; unsigned int i;
for (stat = 0, i = 0; i < max; i++, stat &= ~(e1st|eTry|eSkip|eRet|eOk)) {
stat |= use[0]->_parse(parser);
if ((stat & (eOk|eError)) == eOk)
continue;
return i < min? stat & ~eOk : stat | parser->_chk_stack() | eOk; }
return stat | flag | eOk; }
_Cycle(int at_least, const _Tie& link, int total = maxRepeate, int limit = maxRepeate)
:_Tie(std::string("@")), min(at_least), max(total), flag(total < limit? eNone : eOver|eError)
{ _clue(link); }
public:
~_Cycle()
{ _safe_delete(this); }
friend _Cycle operator*(int at_least, const _Tie& link);
friend _Cycle Repeat(int at_least, const Rule& rule, int total, int limit);
friend _Cycle Iterate(int at_least, const Lexem& lexem, int total, int limit);
friend _Cycle Series(int at_least, const Token& token, int total, int limit);
};
inline _Cycle _Tie::operator*()
{ return _Cycle(0, *this); }
inline _Cycle _Tie::operator!()
{ return _Cycle(0, *this, 1); }
inline _Cycle _Tie::operator()(int at_least, int total)
{ return _Cycle(at_least, *this, total); }
inline _Cycle operator*(int at_least, const _Tie& link)
{ return _Cycle(at_least, link); }
inline _Cycle Repeat(int at_least, const Rule& rule, int total = maxLexemLength, int limit = maxRepeate)
{ return _Cycle(at_least, rule, total, limit); }
inline _Cycle Iterate(int at_least, const Lexem& lexem, int total = maxLexemLength, int limit = maxLexemLength)
{ return _Cycle(at_least, lexem, total, limit); }
inline _Cycle Series(int at_least, const Token& token, int total = maxLexemLength, int limit = maxCharNum)
{ return _Cycle(at_least, token, total, limit); }
/* context class to support the second kind of callback */
template <class U> class _Parser : public _Base
{
protected:
std::vector<U>* cntxU;
unsigned int off;
void _erase(int low, int up = 0)
{ cntxV.erase(cntxV.begin() + low, up? cntxV.begin() + up : cntxV.end() );
if (cntxU && level)
cntxU->erase(cntxU->begin() + (low - off) / 2,
up? cntxU->begin() + (up - off) / 2 : cntxU->end()); }
virtual std::pair<void*, int> _pre_call(void* callback)
{ std::pair<void*, int> up = std::make_pair(cntxU, off);
cntxU = callback? new std::vector<U> : 0;
off = callback? cntxV.size() : 0;
return up; }
virtual void _post_call(std::pair<void*, int> up)
{ if (cntxU) {
delete cntxU; }
cntxU = (std::vector<U>*)up.first;
off = up.second; }
virtual void _do_call(std::pair<void*, int> up, void* callback, size_t org, const char* name)
{ if (callback) {
if (up.first) {
((std::vector<U>*)up.first)->push_back(U(reinterpret_cast<
U(*)(std::vector<U>&)>(callback)(*cntxU), cntxV[org], cntxV.back() - cntxV[org], name));
} else { reinterpret_cast<U(*)(std::vector<U>&)>(callback)(*cntxU); }
} else if (up.first) {
((std::vector<U>*)up.first)->push_back(U(cntxV[org], cntxV.back() - cntxV[org], name)); } }
virtual void _stub_call(size_t org, const char* name)
{ if (cntxU) {
cntxU->push_back(U(cntxV[org], cntxV.back() - cntxV[org], name)); } }
public:
_Parser(const char* (*f)(const char*), std::vector<U>* v) :_Base(f), cntxU(v), off(0)
{};
virtual ~_Parser()
{};
int _get_result(U& u)
{ if (cntxU && cntxU->size()) { u.data = cntxU->front().data; return 0; }
else return eNull; }
template <class W> friend Rule& Bind(Rule& rule, W (*callback)(std::vector<W>&));
};
inline int _Base::_analyze(_Tie& root, const char* text, size_t* plen)
{ cntxV.push_back(text); cntxV.push_back(text);
int stat = root._parse(this);
const char* ptr = zero_parse(pstop > cntxV.back() ? pstop : cntxV.back());
if (plen) *plen = ptr - text;
return stat | (*ptr? eError|eRest: 0); }
/* User interface template to support the second kind of callback */
/* The user need to specify own 'Foo' abstract type to develop own callbaks */
/* like: Interface<Foo> CallBack(std::vector<Interface<Foo>>& res); */
template <typename Data = bool> struct Interface
{
Data data; // user data element
const char* text; // pointer to parsed text according to bound Rule
size_t length; // length of parsed text according to bound Rule
const char* name; // the name of bound Rule
Interface(const Interface& ifc, const char* text, size_t length, const char* name)
:data(ifc.data) , text(text), length(length), name(name)
{}; // mandatory constructor with user data to be called from library
Interface(const char* text, size_t length, const char* name)
:data(), text(text), length(length), name(name)
{}; // mandatory default constructor to be called from library
Interface(Data data, std::vector<Interface>& res, const char* name = "")
:data(data), text(res.size()? res[0].text: ""),
length(res.size()? res[res.size() - 1].text
- res[0].text + res[res.size() - 1].length : 0), name(name)
{}; // constructor to pass data from user's callback to library
Interface(const Interface& front, const Interface& back, const char* name = "")
: data(), text(front.text), length(back.text - front.text + back.length), name(name)
{}; // constructor to pass data from user's callback to library
Interface(): data(), text(0), length(0), name(0)
{}; // default constructor
static Interface ByPass(std::vector<Interface>& res) // simplest user callback example
{ return res.size()? res[0]: Interface(); } // just to pass data to upper level
int _get_pstop(const char** pstop)
{ if (pstop) *pstop = text + length;
return length ? eNone : eNull; }
};
/* Private parsing interface */
template <class U> inline int _Analyze(_Tie& root, U& u, const char* (*pre_parse)(const char*))
{ if (typeid(U) == typeid(Interface<>)) {
_Base base(pre_parse); return base._analyze(root, u.text, &u.length);
} else { std::vector<U> v; _Parser<U> parser(pre_parse, &v);
return parser._analyze(root, u.text, &u.length) | parser._get_result(u); } }
/* Primary interface set to start parsing of text against constructed rules */
template <class U> inline int Analyze(_Tie& root, const char* text, const char** pstop, U& u, const char* (*pre_parse)(const char*) = 0)
{ u.text = text; return _Analyze(root, u, pre_parse) | u._get_pstop(pstop); }
template <class U> inline int Analyze(_Tie& root, const char* text, U& u, const char* (*pre_parse)(const char*) = 0)
{ u.text = text; return _Analyze(root, u, pre_parse) | u._get_pstop(0); }
inline int Analyze(_Tie& root, const char* text, const char** pstop = 0, const char* (*pre_parse)(const char*) = 0)
{ Interface<> u; u.text = text; return _Analyze(root, u, pre_parse) | u._get_pstop(pstop); }
/* Create association between Rule and user's callback */
template <class U> inline Rule& Bind(Rule& rule, U (*callback)(std::vector<U>&))
{ rule.callback = reinterpret_cast<void*>(callback); return rule; }
template <class U> inline Rule& Rule::operator[](U (*callback)(std::vector<U>&)) // for C++11
{ this->callback = reinterpret_cast<void*>(callback); return *this; }
}; // bnf::
#endif // BNFLITE_H