Make volume bold in custom bibliography style .bst

Question

Since I could not find the style that met my teacher's requirements for the bibliography I have to do, I created my own bst with latex makebst on my mac. I had chosen to make the volume bold but it does not appear in boldface on my document (I am using LyX). I was wondering if there is a way to make it appear in bold by modifying the bst file

This is what I have in the volume section

FUNCTION {format.bvolume}
{ volume empty$
    { "" }
    { bbl.volume volume tie.or.space.prefix
      "volume" bibinfo.check * *
      series "series" bibinfo.check
      duplicate$ empty$ 'pop$
        { emphasize ", " * swap$ * }
      if$
      "volume and number" number either.or.check
    }
  if$
}
FUNCTION {format.number.series}
{ volume empty$
    { number empty$
        { series field.or.null }
        { series empty$
            { number "number" bibinfo.check }
            { output.state mid.sentence =
                { bbl.number }
                { bbl.number capitalize }
              if$
              number tie.or.space.prefix "number" bibinfo.check * *
              bbl.in space.word *
              series "series" bibinfo.check *
            }
          if$
        }
      if$
    }
    { "" }
  if$
}

Can someone help me solve this problem ? I tried to add {\bf } around * swap$ * but it does not seem to be working.

Answer 1

The language of BibTeX style is based on reverse Polish notation. This means that it puts strings on a stack and the functions operates on the last element(s) in the stack. Thus to make the current element of the stack bold, one can create the following function

FUNCTION {makebold}{
  "\textbf{" swap$ * "}" * }
}

This function assumes that there is an element on the stack, then it adds the string \textbf{ to the stack, thus after this step the stack is "element" "\textbf{". The instruction swap$ inverts the order of the last two elements in the stack. * replaces the last two elements with their concatenation. Thus after the first * the last element of the stack is "\textbf{element". Then we append "}" to the stack and finally we concatenate it with the previous element. Thus we obtain "\textbf{element}".

After defining the function you can replace emphasize with makebold (or see the comment by Mico about the other relevant functions)