Mysterious vertical space when using \newcommand with expex

Question

Ok, so here's some code that shows off the problem i'm having:

\documentclass[10pt,letterpaper]{article}
\usepackage{expex}

\newcommand{\gloss}[3]{\ex[numoffset=2em,aboveglftskip=0pt]
\begingl
\gla #1//
\glb #2//
\glft #3//
\endgl
\xe}

\begin{document}
\gloss123

blahblahblahblahblahblahblahblahblahblahblahblahblah

\ex[numoffset=2em,aboveglftskip=0pt]
\begingl
\gla 1//
\glb 2//
\glft 3//
\endgl
\xe

blahblahblahblahblahblahblahblahblahblahblahblahblah

\end{document}

This is the output it makes:

As you can see, there's extra vertical space between the first gloss and the blahs. How can I get rid of this while still using \newcommand?

Answer 1

It stems from the fact that \gloss{.}{.}{.} leaves a spurious space in the input stream. You can avoid this by placing a % at the end, or by adding \ignorespaces at the end of your \newcommand definition:

\documentclass{article}
\usepackage{expex}

\newcommand{\gloss}[3]{\ex[numoffset=2em,aboveglftskip=0pt]
\begingl
\gla #1//
\glb #2//
\glft #3//
\endgl
\xe
\ignorespaces}

\begin{document}
\gloss{1}{2}{3}%

blahblahblahblahblahblahblahblahblahblahblahblahblah

\ex[numoffset=2em,aboveglftskip=0pt]
\begingl
\gla 1//
\glb 2//
\glft 3//
\endgl
\xe

blahblahblahblahblahblahblahblahblahblahblahblahblah

\end{document}

Answer 2

I don't know why this is happening but we can work around the issue by adding an negative vertical space \vspace{-\baselineskip}} at the end of the command.

\documentclass[10pt,letterpaper]{article}
\usepackage{expex}

\newcommand{\gloss}[3]{\ex[numoffset=2em,aboveglftskip=0pt]
\begingl
\gla #1//
\glb #2//
\glft #3//
\endgl
\xe
\vspace{-\baselineskip}
}
\begin{document}
\gloss123

blahblahblahblahblahblahblahblahblahblahblahblahblah

\ex[numoffset=2em,aboveglftskip=0pt]
\begingl
\gla 1//
\glb 2//
\glft 3//
\endgl
\xe

blahblahblahblahblahblahblahblahblahblahblahblahblah

\end{document}