Extracting overrightharpoon from MnSymbol

Question

Many previous questions have talked about extracting symbols from MnSymbol, or found alternatives from other packages. However, I have not been able to find a suitable replacement for \overrightharpoon that is in MnSymbol. Indeed, is there a nicer replacement for symbols of this type? It does not appear in any of the earlier summaries and questions.

Bonus: If you could be so nice as to include another symbol with harpoon style tick, but now with a backwards 4 tick (so that \overrightharpoon is a 3-vector, and the new symbol is a 4-vector, that would be much appreciated.

Answer 1

You need to extract the harpoons and also the relation bar:

\documentclass{article}
\usepackage{amsmath}

\makeatletter
\DeclareFontFamily{U}{MnSymbolA}{}
\DeclareFontShape{U}{MnSymbolA}{m}{n}{
    <-6>  MnSymbolA5
   <6-7>  MnSymbolA6
   <7-8>  MnSymbolA7
   <8-9>  MnSymbolA8
   <9-10> MnSymbolA9
  <10-12> MnSymbolA10
  <12->   MnSymbolA12}{}
\DeclareFontShape{U}{MnSymbolA}{b}{n}{
    <-6>  MnSymbolA-Bold5
   <6-7>  MnSymbolA-Bold6
   <7-8>  MnSymbolA-Bold7
   <8-9>  MnSymbolA-Bold8
   <9-10> MnSymbolA-Bold9
  <10-12> MnSymbolA-Bold10
  <12->   MnSymbolA-Bold12}{}
\DeclareSymbolFont{MnSyA}{U}{MnSymbolA}{m}{n}
\SetSymbolFont{MnSyA}{bold}{U}{MnSymbolA}{b}{n}

\DeclareRobustCommand{\overleftharpoon}{\mathpalette{\overarrow@\leftharpoonfill@}}
\DeclareRobustCommand{\overrightharpoon}{\mathpalette{\overarrow@\rightharpoonfill@}}
\def\leftharpoonfill@{\arrowfill@\leftharpoondown\mn@relbar\mn@relbar}
\def\rightharpoonfill@{\arrowfill@\mn@relbar\mn@relbar\rightharpoonup}

\DeclareMathSymbol{\leftharpoondown}{\mathrel}{MnSyA}{'112}
\DeclareMathSymbol{\rightharpoonup}{\mathrel}{MnSyA}{'100}
\DeclareMathSymbol{\mn@relbar}{\mathrel}{MnSyA}{'320}
\makeatother

\begin{document}
$\overrightharpoon{abc}$
$\overleftharpoon{abc}$
\end{document}

Answer 2

REWORKED based on comments from the OP, to provide extensibility.

It is based on my answer at Extensible \vec instead of \overrightarrow

Here, I use the default harpoon to provide extensibility. Method can be extended to other harpoon varieties.

\documentclass[12pt]{scrartcl}
\usepackage{stackengine}
\usepackage{calc}
\newlength\shlength
\newcommand\xshlonghvecr[2][1]{\setlength\shlength{#1pt}%
  \stackengine{-1.0pt}{$#2$}{\smash{$\kern\shlength%
    \stackengine{2.75pt}{$\mathchar"012A$}%
      {\rule{\widthof{$#2$}}{.50pt}\kern1pt}{O}{r}{F}{F}{L}\kern-\shlength$}}%
      {O}{c}{F}{T}{S}}
\newcommand\xshlonghvecl[2][1]{\setlength\shlength{#1pt}%
  \stackengine{-1.0pt}{$#2$}{\smash{$\kern\shlength%
    \stackengine{2.75pt}{\kern-1pt$\mathchar"0128$}%
      {\rule{\widthof{$#2$}}{.50pt}\kern1pt}{O}{l}{F}{F}{L}\kern-\shlength$}}%
      {O}{c}{F}{T}{S}}
\begin{document}
\centering
\[ \vec{A} \quad \xshlonghvecr{ABC} \quad \xshlonghvecr{xy}
 \quad \xshlonghvecr{x} \]
\[ \vec{A} \quad \xshlonghvecl{ABC} \quad \xshlonghvecl{xy}
 \quad \xshlonghvecl{x} \]
\end{document}

Answer 3

I'm not sure to really understand the question (is it a question of fonts or arrows?), but if you're only look for \rightharpoonup and \leftharpoonup macros, I wrote a the overarrows package which redefine them (and other variants).

As example:

\documentclass{article}

\usepackage[overleftharpoonup, overrightharpoonup]{overarrows}

\begin{document}

  \[ \overrightharpoonup{abc} \]

  \[ \overleftharpoonup{abc} \]

  \bigskip

  \TestOverArrow{overleftharpoonup}

  \medskip

  \TestOverArrow{overrightharpoonup}

\end{document}

which gives (\TestOverArrow is a test macro defined by the overarrows package):

If you want symbols from MnSymbol, you can redefine leftharpoonup and rightharpoonup like in egreg's answer:

\documentclass{article}

\DeclareFontFamily{U}{MnSymbolA}{}
\DeclareFontShape{U}{MnSymbolA}{m}{n}{
<-6>  MnSymbolA5
<6-7>  MnSymbolA6
<7-8>  MnSymbolA7
<8-9>  MnSymbolA8
<9-10> MnSymbolA9
<10-12> MnSymbolA10
<12->   MnSymbolA12}{}
\DeclareFontShape{U}{MnSymbolA}{b}{n}{
<-6>  MnSymbolA-Bold5
<6-7>  MnSymbolA-Bold6
<7-8>  MnSymbolA-Bold7
<8-9>  MnSymbolA-Bold8
<9-10> MnSymbolA-Bold9
<10-12> MnSymbolA-Bold10
<12->   MnSymbolA-Bold12}{}
\DeclareSymbolFont{MnSyA}{U}{MnSymbolA}{m}{n}
\SetSymbolFont{MnSyA}{bold}{U}{MnSymbolA}{b}{n}

\DeclareMathSymbol{\leftharpoonup}{\mathrel}{MnSyA}{'112}
\DeclareMathSymbol{\rightharpoonup}{\mathrel}{MnSyA}{'100}

\usepackage[overleftharpoonup, overrightharpoonup]{overarrows}

\begin{document}

\[ \overrightharpoonup{abc} \]

\[ \overleftharpoonup{abc} \]

\bigskip

\TestOverArrow{overleftharpoonup}

\medskip

\TestOverArrow{overrightharpoonup}

\end{document}

or simply add

\usepackage{MnSymbol}

Both give: