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/*
**************************************************************
* C++ Mathematical Expression Toolkit Library *
* *
* Simple Example 18 *
* Author: Arash Partow (1999-2024) *
* URL: https://www.partow.net/programming/exprtk/index.html *
* *
* Copyright notice: *
* Free use of the Mathematical Expression Toolkit Library is *
* permitted under the guidelines and in accordance with the *
* most current version of the MIT License. *
* https://www.opensource.org/licenses/MIT *
* SPDX-License-Identifier: MIT *
* *
**************************************************************
*/
#include <cstdio>
#include <string>
#include "exprtk.hpp"
template <typename T>
void file_io()
{
typedef exprtk::symbol_table<T> symbol_table_t;
typedef exprtk::expression<T> expression_t;
typedef exprtk::parser<T> parser_t;
const std::string fileio_program =
" var file_name := 'file.txt'; "
" var stream := null; "
" "
" if (stream := open(file_name,'w')) "
" println('Successfully opened file: ' + file_name); "
" else "
" { "
" println('Failed to open file: ' + file_name); "
" return [false]; "
" }; "
" "
" var s := 'Hello world...\n'; "
" "
" for (var i := 0; i < 10; i += 1) "
" { "
" write(stream,s); "
" }; "
" "
" if (close(stream)) "
" println('Sucessfully closed file: ' + file_name); "
" else "
" { "
" println('Failed to close file: ' + file_name); "
" return [false]; "
" } ";
exprtk::rtl::io::file::package<T> fileio_package;
exprtk::rtl::io::println<T> println;
symbol_table_t symbol_table;
symbol_table.add_function("println",println);
symbol_table.add_package (fileio_package );
expression_t expression;
expression.register_symbol_table(symbol_table);
parser_t parser;
parser.compile(fileio_program,expression);
printf("Result %10.3f\n",expression.value());
}
int main()
{
file_io<double>();
return 0;
}
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