Subj : Re: Compiler and an interpreter
To   : comp.programming
From : Jon Harrop
Date : Sat Jul 30 2005 03:51 pm

Gerry Quinn wrote:
> Typically an interpreter will stop on the first error.  Compilers in my
> experience usually carry on until a fixed number of errors (e.g. 100)
> have been found, and then stop.

Lots of compilers don't do that.

> Usually in C++, if there are eight errors found, there really are about
> eight.

C++ isn't worth using unless you use the STL, IMHO. Error messages from all
of the compilers that I have seen are completely unwieldy when using the
STL. For example, the following code contains an extra "const":

  #include <iostream>
  #include <list>
  #include <vector>
  #include <algorithm>
  #include <functional>

  int main() {
    std::list<const int> L(7);
    const std::list<int>::const_iterator first_positive =
      std::find_if(L.begin(), L.end(), bind2nd(std::greater<int>(), 0));
    std::cout << (first_positive == L.end() || *first_positive > 0) <<
std::endl;
    return 0;
  }

which gives these errors with g++:

/usr/include/c++/3.3/bits/stl_alloc.h: In instantiation of
`std::allocator<const int>':
test.cc:8:   instantiated from here
/usr/include/c++/3.3/bits/stl_alloc.h:662: error: `const _Tp*
   std::allocator<_Alloc>::address(const _Tp&) const [with _Tp = constint]'
   and `_Tp* std::allocator<_Alloc>::address(_Tp&) const [with _Tp = const
int]
   ' cannot be overloaded
test.cc: In function `int main()':
test.cc:10: error: conversion from `std::_List_iterator<const int, const
int&,
   const int*>' to non-scalar type `std::_List_iterator<int, const int&,
const
   int*>' requested
/usr/include/c++/3.3/bits/stl_construct.h: In function `void
   std::_Construct(_T1*, const _T2&) [with _T1 = const int, _T2 = int]':
/usr/include/c++/3.3/bits/stl_list.h:415:   instantiated from
`std::_List_node<_Tp>* std::list<_Tp, _Alloc>::_M_create_node(const _Tp&)
[with_Tp = const int, _Alloc = std::allocator<const int>]'
/usr/include/c++/3.3/bits/list.tcc:89:   instantiated from
`std::_List_iterator<_Tp, _Tp&, _Tp*> std::list<_Tp,
_Alloc>::insert(std::_List_iterator<_Tp, _Tp&, _Tp*>, const _Tp&) [with _Tp
= const int, _Alloc = std::allocator<const int>]'
/usr/include/c++/3.3/bits/stl_list.h:1066:   instantiated from `void
std::list<_Tp, _Alloc>::_M_fill_insert(std::_List_iterator<_Tp, _Tp&,
_Tp*>, unsigned int, const _Tp&) [with _Tp = const int, _Alloc =
std::allocator<const int>]'
/usr/include/c++/3.3/bits/stl_list.h:833:   instantiated from `void
std::list<_Tp, _Alloc>::insert(std::_List_iterator<_Tp, _Tp&, _Tp*>,
unsigned int, const _Tp&) [with _Tp = const int, _Alloc =
std::allocator<const int>]'
/usr/include/c++/3.3/bits/stl_list.h:478:   instantiated from
`std::list<_Tp, _Alloc>::list(unsigned int) [with _Tp = const int, _Alloc =
std::allocator<const int>]'
test.cc:8:   instantiated from here
/usr/include/c++/3.3/bits/stl_construct.h:78: error: invalid static_cast
from
   type `const int*' to type `void*'

> When there are 100 errors, you left out a curly bracket 
> somewhere above the first one, or something like that.

What you are saying is true in C but not in C++.

-- 
Dr Jon D Harrop, Flying Frog Consultancy
http://www.ffconsultancy.com

.