Whether $name can be used bare or needs the ${name} brace form — mirrors the tokenizer's identifier rule (interpolate in src/vars/mod.rs only greedily consumes [A-Za-z0-9_] after a bare $).
$name
${name}
interpolate
[A-Za-z0-9_]
$
Whether
$namecan be used bare or needs the${name}brace form — mirrors the tokenizer's identifier rule (interpolatein src/vars/mod.rs only greedily consumes[A-Za-z0-9_]after a bare$).