parse.hpp File Reference

#include <istream>
#include <locale>
#include <ostream>
#include <stdexcept>
#include <string>

Go to the source code of this file.

Classes
class	parse_error
class	parser
Functions
void	parse_loop (std::istream &input, std::ostream &output)

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Function Documentation

void parse_loop	(	std::istream &	input,
		std::ostream &	output
	)

Parse loop. Read expressions from input and print results to output.

Parameters:

	input	The input stream.
	output	The output stream.

Definition at line 272 of file parse.cpp.

References node::evaluate(), and parser::get_expr().

{
  std::string line;
  // No portable way to test whether the console is an interactive terminal
  // vs. a non-interactive file. If you have a system-specific way to test,
  // output the prompt only for the interactive case.
  for (output << "> "; std::getline(input, line); output << "> ") {
    std::istringstream input(line);
    parser p(input);
    try {
      node n;
      while (p.get_expr(n))
        output << n.evaluate() << '\n';
    } catch(parse_error const& ex) {
      output << ex.what() << '\n';
    } catch(std::exception const& ex) {
      output << "exception: " << ex.what() << '\n';
    }
  }
}

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