Inline `Array#filter`

filter.macro.sjs

macro inline_filter {
  rule { ($list:expr, function ($value:ident, $index:ident, $ref:ident) {
    $return:expr
  }, $context:expr) } => {
    (function ($ref) {
      var length = $ref.length, res = [];

      for (var $index = 0; $index < length; $index += 1) {
        var $value = $ref[$index];

        if ($return) res.push($value);
      }

      return res;
    }.call($context, $list))
  }
}

let filter = macro {
	rule infix { $list:expr . | (() => $return:expr) } => {
		inline_filter($list, function (value, index, ref) { $return }, this)
	}
	rule infix { $list:expr . | (() => $return:expr, $context:expr) } => {
		inline_filter($list, function (value, index, ref) { $return }, this)
	}
	rule infix { $list:expr . | ($value:ident => $return:expr) } => {
		inline_filter($list, function ($value, index, ref) { $return }, this)
	}
	rule infix { $list:expr . | ($value:ident => $return:expr, $context:expr) } => {
		inline_filter($list, function ($value, index, ref) { $return }, this)
	}
	rule infix { $list:expr . | (($value:ident) => $return:expr) } => {
		inline_filter($list, function ($value, index, ref) { $return }, this)
	}
	rule infix { $list:expr . | (($value:ident) => $return:expr, $context:expr) } => {
		inline_filter($list, function ($value, index, ref) { $return }, this)
	}
	rule infix { $list:expr . | (($value:ident, $index:ident) => $return:expr) } => {
		inline_filter($list, function ($value, $index, ref) { $return }, this)
	}
	rule infix { $list:expr . | (($value:ident, $index:ident) => $return:expr, $context:expr) } => {
		inline_filter($list, function ($value, $index, ref) { $return }, this)
	}
	rule infix { $list:expr . | (($value:ident, $index:ident, $ref:ident) => $return:expr) } => {
		inline_filter($list, function ($value, $index, $ref) { $return }, this)
	}
	rule infix { $list:expr . | (($value:ident, $index:ident, $ref:ident) => $return:expr, $context:expr) } => {
		inline_filter($list, function ($value, $index, $ref) { $return }, this)
	}
	rule { $rest ... } => { some $rest ... }
}

export filter;

let filter = macro {
	rule infix { $list:expr . | (() => $return:expr) } => {
		inline_filter($list, function (value, index, ref) { $return }, this)
	}
	rule infix { $list:expr . | ($value:ident => $return:expr) } => {
		inline_filter($list, function ($value, index, ref) { $return }, this)
	}
	rule infix { $list:expr . | (($value:ident) => $return:expr) } => {
		inline_filter($list, function ($value, index, ref) { $return }, this)
	}
	rule infix { $list:expr . | (($value:ident, $index:ident) => $return:expr) } => {
		inline_filter($list, function ($value, $index, ref) { $return }, this)
	}
	rule infix { $list:expr . | (($value:ident, $index:ident, $ref:ident) => $return:expr) } => {
		inline_filter($list, function ($value, $index, $ref) { $return }, this)
	}
	rule { $rest ... } => { filter $rest ... }
}

export filter;