Left expression patterns

[bvssvni]

Would be nice to have patterns in left side expressions to declare multiple variables at once:

[a, b] := [1, 2]
{x: a, y: y} := {x: 1, y: 2}
{x, y} := {x: 1, y: 2}

[bvssvni]

Could use rewrite of the AST:

[a, b] := [1, 2]

becomes:

_tmp := [1, 2]
a := _tmp[0]
b := _tmp[1]