How make newtx option theoremfont work with thmtools?

Question

I want the body of theorems to be in a true slanted font (\slshape) rather than in italic, yet have brackets within a theorem body to be upright.

The newtx package (version 1.7) option theoremfont (and the same option to the newtxtext package) makes text in the body of an amsthm theorem body slanted yet keep brackets there upright.

Is it possible somehow to cause that same option to have the same effect when declaring theorem styles via the thmtools package?

If, as in the following source, I use newtx option theoremfont and define the theorem style via thmtools, then the entire theorem body font is upright, including brackets there.

\documentclass{memoir}
\usepackage[amsthm,theoremfont]{newtx} % loads fontspec & amsthm, too
\usepackage{thmtools}
\swapnumbers
\declaretheoremstyle[
  headfont=\sffamily\bfseries, headpunct={\sffamily\bfseries.},
  % bodyfont=\mdseries\slshape,
]{thmstyle}
\declaretheorem[style=thmstyle,name=Theorem]{theorem}
\begin{document}
\chapter{The Chapter}
\section{Here is a section}
\begin{theorem}[Pythagorean theorem]
In a right triangle [that is, with one angle a right angle],
the square of the length of the hypotenuse equals
the sum of the squares of the lengths of the other two sides.
\end{theorem}
\end{document}

If, however, I add to the theorem style definition the option

  bodyfont=\mdseries\slshape,

then the entire theorem body is slanted, including, unfortunatetly, brackets, as shown here:

I am aware of two workarounds:

1. load package embrac and then use \embbracket{...} for the bracketed text; or
2. use \textup{[} and `\textup{]}1 to delimit the bracketed text.

But both methods are "manual," whereas I am looking for an automatic method.

Related:

Upright brackets in theorem body with bodyfont=\mdseries\itshape?

Embrac package and enumerate

Upright parentheses in italic text

Copy theoremfont option from newtxtext

Added: comparison with newtx and amsthm

By contrast, the following source produces a theorem body with slanted text, except that brackets, parentheses, numerals, and punctuation are set upright:

\documentclass{article}
\usepackage[amsthm,theoremfont]{newtx}
\theoremstyle{plain}
\newtheorem{thm}{Theorem}
\begin{document}
\begin{thm}
In a right triangle [that is, a triangle with one right angle]: the square of (the length of) the hypotenuse equals the some of the squares of the other 2 sides.
\end{thm}
\end{document}

Answer 1

At least with newtx version 1.732, we get slanted text for the body of theorems (but upright parentheses and brackets there) by using option thmslshape (without option theoremfont) together with keyword value bodyfont=\thfamily in a thmtools theorem-style declaraion.

This works with both pdflatex and xelatex.

For example:

  \documentclass{article}
  \usepackage[amsthm,thmslshape]{newtx} % loads fontspec & amsthm, too
\usepackage{thmtools}
  \swapnumbers
  \declaretheoremstyle[
    headfont=\sffamily\bfseries, headpunct={\sffamily\bfseries.},
    bodyfont=\thfamily,
  ]{thmstyle}
  \declaretheorem[style=thmstyle,name=Theorem]{theorem}
\begin{document}
\section{Here is a section}
\begin{theorem}[Pythagorean theorem]
In a right triangle [that is, with one angle a right angle],
  the square of the length of the hypotenuse (the slanted side if the legs are parallel to the axes!) equals
  the sum of the squares of the lengths of the other two sides.
\end{theorem}
In normal text that is \emph{emphasized (that is, by default italicized),} we do not get slanted.
\end{document}