Ccompiler bug for concatenated strings in a condition

[Carlo Hogeveen]

 

I ran into a small compiler bug today.

It feels familiar, so it might be a known one.

See the example macro below.

As demonstrated, it is very easy to work around.

 

Carlo

 

 

 

proc Main()

  //  Example of a compiler error that does not make sense

  //  according to TSE's "Precedence ..." documentation.

 

  //  This "if" statement is of course compilable.

  //  if 'ab' == ('a' + 'b')

 

  //  Unexpectedly this "if" statement is not compilable.

  if 'ab' == 'a' + 'b'

 

    Warn('Yes')

  else

    Warn('No')

  end

 

  PurgeMacro(CurrMacroFilename())

end Main

 

 

[knud van eeden]

Probably best to use the workaround of parentheses and just nothing this in e.g. the read.me as a known issue / bug.

Because it might break backwards existing source code which has a much larger collateral damage effect.

with friendly greetings

Knud van Eeden

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[knud van eeden]

Probably best to use the workaround of parentheses and just noting this in e.g. the read.me as a known issue / bug.

[knud van eeden]

In general changing the priority of operators like '==' and '+' is a very fundamental action which

can have large side effects thus in calculations / expressions and should not be changed (anymore).

[knud van eeden]

From the example I would thus at first glance assume that it is read as

( 'ab' == 'b' ) + 'c'

instead of the at the end of the day intended

'ab' == ( 'b' + 'c' )

From this follows that in the TSE expression parsing the operation '==' has *by definition* a higher

priority than '+'.

Thus the compiler error is actually not an error, but follows from its definition, so it is more of a

user error, and one *must* use parentheses to achieve what one wants.

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[S.E. Mitchell]

Yep, definitely a bug. + should have higher precedence than ==.
I'll add it to the list.