Using unicode ℝ as commands \mathbb{R}

Question

I want to use a unicode character, say $ℝ$, and get the equivalent command $\mathbb{R}$. So what I want is something like

\newcommandℝ{\mathbb{R}}  //it won't work by default, of course

How can I do this? I know this is not related to use unicode-math package, because unicode-math package transform unicode to corresponding output, however I just want to use some unicode characters as a shorthand only (to increase the readibility).

Answer 1

\documentclass{article}
\usepackage{amssymb}
\usepackage[utf8]{inputenc}
\usepackage{newunicodechar}
\newunicodechar{ℝ}{\mathbb{R}}
\begin{document}

$ \mathbb{R} =1$ 

$ ℝ = 1 $

\end{document}

For XeLaTeX you can just remove the inputenc package, but in this case is simpler the David's suggestion of use unicode-math.

Answer 2

If you are using

\usepackage[utf8]{inputenc}

then just add

\DeclareUnicodeCharacter{211D}{\mathbb{R}}

With unicode TeX engines it is probably advisable to use unicode-math which would allow ℝ to be typeset directly, but if you are using 8bit math fonts still then you can use

\catcode`ℝ=13
\newcommandℝ{\mathbb{R}}