Expand control flow to a generic syntax?

[aredridel]

It seems that there could be a grammar that says one {#token arguments}, other syntax, n {:otherToken arguments} , other syntax, {/token} as a general pattern — it'd handle if, else, await, then, try, catch and each at least. It would require specifying productions for arguments that include, perhaps barewords and javascript expressions to allow a parser to remain generic.