How to put a curvearrow around a letter?

Something like this, with the nccircle command from pst-node?

documentclass[12pt]{article}
usepackage{pst-node}

begin{document}

    psset{arrowinset=0.1}
    $psDefBoxNodes{A}{A}nccircle[nodesep =5pt]{->}{A:bC}{0.6em}$%

end{document} 

You could use curvearrowleft from AMS Symbols, e.g.:

documentclass{article}

usepackage{amssymb}
newcommand{curvearrow}[1]{ooalign{kern1pt ensuremath{#1}crhidewidthraise.8exhbox{$curvearrowleft$}hidewidth}}

begin{document}

$curvearrow{a}, curvearrow{b}, curvearrow{c}$

end{document}

Perhaps you have to tweak the distances, e.g. to cover capital letters.

Not sure if this looks too appealing but maybe this goes in the right direction.

documentclass{article}
usepackage{mathtools}
usepackage{amssymb}
usepackage{scalerel}
newcommandOverCurveArrowRight[2][n]{%
setbox0hbox{scalerel*{curvearrowright}{overset{#1}{#2}}}copy0%
mathllap{mathmakebox[wd0]{#2hskip0.2wd0}}}
newcommandOverCurveArrowLeft[2][n]{%
setbox0hbox{scalerel*{curvearrowleft}{overset{#1}{#2}}}copy0%
mathllap{mathmakebox[wd0]{hskip0.2wd0#2}}}
begin{document}
abc $OverCurveArrowRight{A}$ $OverCurveArrowLeft{A}$ 
[OverCurveArrowRight{A}toOverCurveArrowLeft{A}]
[OverCurveArrowRight[int]{int}toOverCurveArrowLeft{A}]
end{document}

Starting from the code of the answer of the user @egreg in this question How to write a character overlapping another character I have adapted this using the packages graphicx, scalerel to have a little big arrow and to rotate the symbol circlearrowleft of 170 degrees (for example).

documentclass[a4paper,12pt]{article}
usepackage{newtxtext,newtxmath}
usepackage{graphicx,scalerel}
makeatletter
DeclareRobustCommand{as}[1]{
  {vphantom{#1}mathpaletteerel@as{#1}}%
}
newcommand{cla}{rotatebox[origin=c]{170}{hstretch{1}{$scaleobj{1.5}{circlearrowleft}$}}}
newcommand{erel@as}[2]{%
  ooalign{hfil$m@th#1cla$hfilcrhfil$m@th#1#2$hfilcr}%
}
makeatother  

begin{document}
$as{A}$

end{document}