syntax: put helpers of `parse_self_param` in the method.
syntax: put helpers of `parse_self_param` in the method.

aidancully/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,graydon/rust