ezc/src/funinfo.h

284 lines
6.8 KiB
C++

/*
* This file is a part of EZC -- Easy templating in C++ library
* and is distributed under the BSD 3-Clause licence.
* Author: Tomasz Sowa <t.sowa@ttmath.org>
*/
/*
* Copyright (c) 2007-2016, Tomasz Sowa
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name Tomasz Sowa nor the names of contributors to this
* project may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef headerfile_ezc_funinfo
#define headerfile_ezc_funinfo
#include <vector>
#include "item.h"
namespace Ezc
{
/*
a variable
*/
struct Var
{
std::wstring str; // a string value
bool res; // a boolean value
};
/*
a base class for your own function data class
*/
struct FunData
{
FunData()
{
}
virtual ~FunData()
{
}
};
/*
a generator's stack item
each statement ([if ...] [for ...] [normal_funcion]) have its own stack item
iter - is used only in [for...] - it is the current iteration (start from zero)
for other statements it is always zero
fun_data - by default this is null pointer, you can set it to a pointer
to an object derived from FunData
(this have sense only in [for...] statement because in other statements
this object would be immediately removed)
auto_remove - when true it means that object pointing by fun_data and for_name should be automatically
removed -- (by using delete fun_data and delete for_name)
is_for - true if the item is from [for] statement
currently used only in [if-index]
(it has to look for the last [for] item)
*/
struct Stack
{
size_t iter;
FunData * fun_data;
bool auto_remove;
bool is_for;
const Item * item;
Stack()
{
Clear();
}
~Stack()
{
if( auto_remove )
{
if( fun_data )
{
delete fun_data;
fun_data = 0;
}
}
}
void Clear()
{
iter = 0;
fun_data = 0;
auto_remove = true;
is_for = false;
item = 0;
}
};
// !! IMPROVE ME
// the name is bad
// may it should be called Env (environment) or FunEnv
template<class StreamType>
struct FunInfo
{
// a result consists of a string and a boolean value
// output stream
StreamType & out;
// return value from a user's function (default false if not set directly by the function)
bool res;
// table of parameters
// the table can be empty
std::vector<Var> & params;
// the first parameter
// you can always use it even if there are not any parameters (params is empty)
// in such a way the reference points to an empty string
const std::wstring & par;
// an input stream used in [filter] statement
// if there is other statement than [filter] then this is an empty stream
const StreamType & in;
// indicates that this function is from [for ...] statement
bool is_for;
// indicates that this function is from [if ...] statement
// it is true for all kind of if's: if-one, if-any, if-no....
bool is_if;
// indicates that this funcion is a normal statement e.g.: [funcion_name]
bool is_normal;
// indicates that this function is from a filter statement [filter ...]
bool is_filter;
// a pointer to the stack
Stack * stack_tab;
// current stack item
size_t stack_index;
// a stack's item from generator's stack
// each function has a new stack item
// on this stack you have iter (description below) and fun_data pointer
// you can assign to it your own object derived from FunData
// 'stack' is a reference to stack_tab[stack_index]
Stack & stack;
// the same as stack.iter (this is mainly for backward compatibility)
// it indicates the number of a current iteration for the [for] statement (the first iteration is 0)
// for other statements than [for] this is always zero
size_t iter;
//
const Item & item;
// arguments: output_stream, table_of_parameters, the_first_parameter
FunInfo(StreamType & o,
std::vector<Var> & pars,
const std::wstring & first_par,
const StreamType & input_stream,
Stack & s,
const Item & item_) : out(o), params(pars), par(first_par), in(input_stream), stack(s), item(item_)
{
Clear();
}
void Clear()
{
res = false; // result is false by default
is_for = false;
is_if = false;
is_normal = false;
is_filter = false;
iter = 0;
stack_tab = 0;
stack_index = 0;
}
/*
* CHECK ME can it be done only for [for] statements?
*
* can return a null pointer if there is no such an item on the stack
*
* add a function with const wchar_t *
*/
Stack * FindLastFor(const std::wstring & name)
{
for(size_t i = stack_index ; i > 0 ; --i)
{
if( stack_tab[i-1].is_for && stack_tab[i-1].item->has_function )
{
if( stack_tab[i-1].item->function.name == name )
{
return &stack_tab[i-1];
}
}
}
return 0;
}
Stack * FindLastFor(const std::wstring & name, const std::wstring & postfix)
{
for(size_t i = stack_index ; i > 0 ; --i)
{
if( stack_tab[i-1].is_for && stack_tab[i-1].item->has_function )
{
if( stack_tab[i-1].item->function.name == name && stack_tab[i-1].item->function.postfix == postfix )
{
return &stack_tab[i-1];
}
}
}
return 0;
}
template<class FunUserObject>
FunUserObject * FindUserObject(const std::wstring & function_name, Stack ** ezc_stack = 0)
{
Stack * stack;
if( item.has_function && item.function.is_function )
stack = FindLastFor(function_name, item.function.postfix);
else
stack = FindLastFor(function_name);
if( ezc_stack )
*ezc_stack = stack;
if( stack && stack->fun_data )
return dynamic_cast<FunUserObject*>(stack->fun_data);
return 0;
}
};
} // namespace Ezc
#endif