lyx_mirror/src/lyxlex.C
Abdelrazak Younes 4d5ae916ad Fix bug 3293 by Bernhard Roider:
This changes the semantics of isOK() and operator(), comments from Bernhard below:

With the old version of lyxlex it was _impossible_ to check whether reading an integer, float, ... succeeded or not. The current solution to check for is.bad() in some cases and in other cases use is.good() does not give the desired information. Moreover the result of is.bad() depends on the stl implementation and behaves different for linux and windows.

the bug was introduced by the patch that fixed the bug that crashed lyx when "inset-insert ert" was executed from the command buffer.
The lexer has the method isOK() which reflects the status of the stream is.
The operators void* and ! are not really well defined (they depend on the value of is.bad()). What is missing is a test if the last reading operation was successful and thus the returned value is valid.
That's what i implemented in this patch.

The new rule for using the lexer:

if you want to know if the lexer still has data to read (either from the stream or from the pushed token) then use "lex.isOK()".
If you want to test if the last reading operation was successful then use eg. "if (lex) {...}" or unsuccessful then use eg. "if (!lex) {...}"

an example:

int readParam(LyxLex &lex) {

    int param = 1; // default value
    if (lex.isOK()) { // the lexer has data to read
        int p;    // temporary variable
        lex >> p;
        if (lex) param = p; // only use the input if the reading operation was successful
    }
    return param;
}




git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@17569 a592a061-630c-0410-9148-cb99ea01b6c8
2007-03-26 13:43:49 +00:00

370 lines
6.2 KiB
C

/**
* \file lyxlex.C
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author Alejandro Aguilar Sierra
* \author Lars Gullik Bjønnes
* \author Jean-Marc Lasgouttes
* \author John Levon
*
* Full author contact details are available in file CREDITS.
*/
#include <config.h>
#include "lyxlex.h"
#include "debug.h"
#include "lyxlex_pimpl.h"
#include "support/convert.h"
#include "support/lstrings.h"
#include <sstream>
namespace lyx {
using support::compare_ascii_no_case;
using support::isStrDbl;
using support::isStrInt;
using support::ltrim;
using support::prefixIs;
using support::subst;
using support::trim;
using std::endl;
using std::string;
using std::istream;
using std::ostream;
LyXLex::LyXLex(keyword_item * tab, int num)
: pimpl_(new Pimpl(tab, num))
{}
LyXLex::~LyXLex()
{
delete pimpl_;
}
bool LyXLex::isOK() const
{
return pimpl_->inputAvailable();
}
void LyXLex::setLineNo(int l)
{
pimpl_->lineno = l;
}
int LyXLex::getLineNo() const
{
return pimpl_->lineno;
}
istream & LyXLex::getStream()
{
return pimpl_->is;
}
void LyXLex::pushTable(keyword_item * tab, int num)
{
pimpl_->pushTable(tab, num);
}
void LyXLex::popTable()
{
pimpl_->popTable();
}
void LyXLex::printTable(ostream & os)
{
pimpl_->printTable(os);
}
void LyXLex::printError(string const & message) const
{
pimpl_->printError(message);
}
bool LyXLex::setFile(support::FileName const & filename)
{
return pimpl_->setFile(filename);
}
void LyXLex::setStream(istream & i)
{
pimpl_->setStream(i);
}
void LyXLex::setCommentChar(char c)
{
pimpl_->setCommentChar(c);
}
int LyXLex::lex()
{
return pimpl_->lex();
}
int LyXLex::getInteger() const
{
lastReadOk_ = pimpl_->status == LEX_DATA || pimpl_->status == LEX_TOKEN;
if (!lastReadOk_) {
pimpl_->printError("integer token missing");
return -1;
}
if (isStrInt(pimpl_->getString()))
return convert<int>(pimpl_->getString());
lastReadOk_ = false;
pimpl_->printError("Bad integer `$$Token'");
return -1;
}
double LyXLex::getFloat() const
{
// replace comma with dot in case the file was written with
// the wrong locale (should be rare, but is easy enough to
// avoid).
lastReadOk_ = pimpl_->status == LEX_DATA || pimpl_->status == LEX_TOKEN;
if (!lastReadOk_) {
pimpl_->printError("float token missing");
return -1;
}
string const str = subst(pimpl_->getString(), ",", ".");
if (isStrDbl(str))
return convert<double>(str);
lastReadOk_ = false;
pimpl_->printError("Bad float `$$Token'");
return -1;
}
string const LyXLex::getString() const
{
lastReadOk_ = pimpl_->status == LEX_DATA || pimpl_->status == LEX_TOKEN;
if (lastReadOk_)
return pimpl_->getString();
return string();
}
docstring const LyXLex::getDocString() const
{
lastReadOk_ = pimpl_->status == LEX_DATA || pimpl_->status == LEX_TOKEN;
if (lastReadOk_)
return pimpl_->getDocString();
return docstring();
}
// I would prefer to give a tag number instead of an explicit token
// here, but it is not possible because Buffer::readDocument uses
// explicit tokens (JMarc)
string const LyXLex::getLongString(string const & endtoken)
{
string str, prefix;
bool firstline = true;
while (pimpl_->is) { //< eatLine only reads from is, not from pushTok
if (!eatLine())
// blank line in the file being read
continue;
string const token = trim(getString(), " \t");
lyxerr[Debug::PARSER] << "LongString: `"
<< getString() << '\'' << endl;
// We do a case independent comparison, like search_kw does.
if (compare_ascii_no_case(token, endtoken) == 0)
break;
string tmpstr = getString();
if (firstline) {
string::size_type i(tmpstr.find_first_not_of(' '));
if (i != string::npos)
prefix = tmpstr.substr(0, i);
firstline = false;
lyxerr[Debug::PARSER]
<< "Prefix = `" << prefix << "\'" << endl;
}
// further lines in long strings may have the same
// whitespace prefix as the first line. Remove it.
if (prefix.length() && prefixIs(tmpstr, prefix)) {
tmpstr.erase(0, prefix.length() - 1);
}
str += ltrim(tmpstr, "\t") + '\n';
}
if (!pimpl_->is) {
printError("Long string not ended by `" + endtoken + '\'');
}
return str;
}
bool LyXLex::getBool() const
{
if (pimpl_->getString() == "true") {
lastReadOk_ = true;
return true;
} else if (pimpl_->getString() != "false") {
pimpl_->printError("Bad boolean `$$Token'. "
"Use \"false\" or \"true\"");
lastReadOk_ = false;
}
lastReadOk_ = true;
return false;
}
bool LyXLex::eatLine()
{
return pimpl_->eatLine();
}
bool LyXLex::next(bool esc)
{
return pimpl_->next(esc);
}
bool LyXLex::nextToken()
{
return pimpl_->nextToken();
}
void LyXLex::pushToken(string const & pt)
{
pimpl_->pushToken(pt);
}
LyXLex::operator void const *() const
{
// This behaviour is NOT the same as the std::streams which would
// use fail() here. However, our implementation of getString() et al.
// can cause the eof() and fail() bits to be set, even though we
// haven't tried to read 'em.
return lastReadOk_? this: 0;
}
bool LyXLex::operator!() const
{
return !lastReadOk_;
}
LyXLex & LyXLex::operator>>(std::string & s)
{
if (isOK()) {
next();
s = getString();
} else {
lastReadOk_ = false;
}
return *this;
}
LyXLex & LyXLex::operator>>(docstring & s)
{
if (isOK()) {
next();
s = getDocString();
} else {
lastReadOk_ = false;
}
return *this;
}
LyXLex & LyXLex::operator>>(double & s)
{
if (isOK()) {
next();
s = getFloat();
} else {
lastReadOk_ = false;
}
return *this;
}
LyXLex & LyXLex::operator>>(int & s)
{
if (isOK()) {
next();
s = getInteger();
} else {
lastReadOk_ = false;
}
return *this;
}
LyXLex & LyXLex::operator>>(unsigned int & s)
{
if (isOK()) {
next();
s = getInteger();
} else {
lastReadOk_ = false;
}
return *this;
}
LyXLex & LyXLex::operator>>(bool & s)
{
if (isOK()) {
next();
s = getBool();
} else {
lastReadOk_ = false;
}
return *this;
}
/// quotes a string, e.g. for use in preferences files or as an argument of the "log" dialog
string const LyXLex::quoteString(string const & arg)
{
std::ostringstream os;
os << '"' << subst(subst(arg, "\\", "\\\\"), "\"", "\\\"") << '"';
return os.str();
}
} // namespace lyx