> Line continuation in Elvish uses ^ instead of \
> Bash: echo .[ch] vs Elvish: echo .?[set:ch]
One more example, guess what this does: `echo &sep=',' foo bar`. Is it bash, elvish? Some combination of the two with markdown? Legal in all three? Elvish certainly cleans up conditionals and stuff, but you probably shouldn't introduce new things with exactly the same name unless you've created a genuine superset/dialect where the older version still works without rewrite. Namespace it as elvish.echo or use your module system. Shadows aren't friendly, this is equivalent to the guy that monkey-patches sys.stderr=sys.stdout to work around their one-off problem