Multi token names are eating tokens

Created by: natefaubion

macro -> {
  rule infix { $arg:ident | $body:expr } => {
    function($arg) { return $body }
  }
}

var a = x -> x - 1;
var b = x -> x + 2;
var c = x -> x - 3;

var a$305 = function (x$313) {
    return -1;
};
var b$307 = function (x$314) {
    return x$314 + 2;
};
var c$309 = function (x$315) {
    return -3;
};

Likewise, if I were to change it to +> it would eat the identifier for the plus fn:

macro +> {
  rule infix { $arg:ident | $body:expr } => {
    function($arg) { return $body }
  }
}

var a = x +> x - 1;
var b = x +> x + 2;
var c = x +> x - 3;

var a$305 = function (x$313) {
    return x$313 - 1;
};
var b$307 = function (x$314) {
    return +2;
};
var c$309 = function (x$315) {
    return x$315 - 3;
};