I want to use arrows to talk about edges in graphs. For example I write $\to \to$ to represent two adjacent directed edges.
An undirected edge followed by a directed edge would be represented by something like $- \to$, but this looks bad, because the line $-$ is shorter than $\to$.
How do you make $-$ longer? Line drawing commands like rule or \tikz\draw do not look right, because they make a rectangle with sharp corners unlike the rounded corners of \to. (or perhaps making $\to$ shorter is the better way?)