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// file : butl/tab-parser.cxx -*- C++ -*-
// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
// license : MIT; see accompanying LICENSE file
#include <butl/tab-parser>
#include <cassert>
#include <sstream>
using namespace std;
namespace butl
{
using parsing = tab_parsing;
// tab_parser
//
tab_fields tab_parser::
next ()
{
tab_fields r;
xchar c (skip_spaces ()); // Skip empty lines and leading spaces.
auto eol = [&c] () -> bool {return eos (c) || c == '\n';};
auto space = [&c] () -> bool {return c == ' ' || c == '\t';};
auto next = [&c, this] () {get (); c = peek ();};
r.line = c.line;
// Read line fields until eos or the newline character.
//
while (!eol ())
{
for (; !eol () && space (); next ()) ; // Skip space characters.
if (eol ()) // No more fields.
break;
// Read the field. Here we scan until the first whitespace character that
// appears out of quotes.
//
tab_field tf ({string (), c.column});
char quoting ('\0'); // Current quoting mode, can be used as bool.
for (; !eol (); next ())
{
if (!quoting)
{
if (space ()) // End of the field.
break;
else if (c == '"' || c == '\'') // Begin of quoted string.
quoting = c;
}
else if (c == quoting) // End of quoted string.
quoting = '\0';
tf.value += c;
}
if (quoting)
throw parsing (name_, c.line, c.column, "unterminated quoted string");
r.emplace_back (move (tf));
}
r.end_column = c.column;
// Read out eof or newline character from the stream. Note that "reading"
// eof multiple times is safe.
//
get ();
return r;
}
tab_parser::xchar tab_parser::
skip_spaces ()
{
xchar c (peek ());
bool start (c.column == 1);
for (; !eos (c); c = peek ())
{
switch (c)
{
case ' ':
case '\t':
break;
case '\n':
{
// Skip empty lines.
//
if (!start)
return c;
break;
}
case '#':
{
// We only recognize '#' as a start of a comment at the beginning
// of the line (sans leading spaces).
//
if (!start)
return c;
get ();
// Read until newline or eos.
//
for (c = peek (); !eos (c) && c != '\n'; c = peek ())
get ();
continue;
}
default:
return c; // Not a space.
}
get ();
}
return c;
}
// tab_parsing
//
static string
format (const string& n, uint64_t l, uint64_t c, const string& d)
{
ostringstream os;
if (!n.empty ())
os << n << ':';
os << l << ':' << c << ": error: " << d;
return os.str ();
}
tab_parsing::
tab_parsing (const string& n, uint64_t l, uint64_t c, const string& d)
: runtime_error (format (n, l, c, d)),
name (n), line (l), column (c), description (d)
{
}
}
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