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// file : libbpkg/buildfile-scanner.hxx -*- C++ -*-
// license : MIT; see accompanying LICENSE file
#ifndef LIBBPKG_BUILDFILE_SCANNER_HXX
#define LIBBPKG_BUILDFILE_SCANNER_HXX
#include <string>
#include <cstdint> // uint64_t
#include <cstddef> // size_t
#include <stdexcept> // runtime_error
#include <libbutl/char-scanner.hxx>
#include <libbpkg/export.hxx>
namespace bpkg
{
// Scan buildfile fragments, respecting the single- and double-quoted
// character sequences, backslash-escaping, comments, evaluation
// contexts, and nested blocks.
//
class LIBBPKG_EXPORT buildfile_scanning: public std::runtime_error
{
public:
buildfile_scanning (const std::string& name,
std::uint64_t line,
std::uint64_t column,
const std::string& description);
std::string name;
std::uint64_t line;
std::uint64_t column;
std::string description;
};
template <typename V, std::size_t N>
class buildfile_scanner
{
public:
// Note that name is stored by shallow reference.
//
buildfile_scanner (butl::char_scanner<V, N>& s, const std::string& name)
: scan_ (s), name_ (name) {}
// Scan the buildfile line and return the scanned fragment. Optionally,
// specify an additional stop character. Leave the newline (or the stop
// character) in the stream. Throw buildfile_scanning on error
// (unterminated quoted sequence, etc).
//
std::string
scan_line (char stop = '\0');
// Scan the buildfile line until an unbalanced ')' character is encountered
// and return the scanned fragment, leaving ')' in the stream. Throw
// buildfile_scanning on error or if eos or newline is reached.
//
std::string
scan_eval ();
// Scan the buildfile block until an unbalanced block closing '}' character
// is encountered and return the scanned fragment. Throw buildfile_scanning
// on error or if eos is reached.
//
// Note that the block opening '{' and closing '}' characters are only
// considered as such, if they are the only characters on the line besides
// whitespaces and comments. Also note that the fragment terminating '}'
// line is consumed from the stream but is not included into the fragment.
//
std::string
scan_block ();
private:
using scanner = butl::char_scanner<V, N>;
using xchar = typename scanner::xchar;
xchar
peek ();
// Scan the buildfile line, saving the scanned characters into the
// specified string, leaving newline and the stop character, if specified,
// in the stream. Return '{' if this line is a block-opening curly brace,
// '}' if it is a block-closing curly brace, and '\0' otherwise.
//
char
scan_line (std::string& l, char stop = '\0');
private:
scanner& scan_;
const std::string& name_;
std::string ebuf_; // Error message buffer.
};
}
#include <libbpkg/buildfile-scanner.txx>
#endif // LIBBPKG_BUILDFILE_SCANNER_HXX
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