methods_ex

#!/bin/bash
#
# Introduces `methods` and their association with structs.

readonly DIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
. ${DIR}/../gobash


function Request() {
        local -r url="${1}"
        shift 1

        make_ $FUNCNAME \
              "url" "${url}"
}

# Adding a method (named `curl`) for the `struct` `Request`. Note that
# the method name has to be prefixed by the name of the struct.
function Request_curl() {
        # The first argument of each method is an instance on which
        # the method was invoked (think of it as `this` or
        # `self`). Subsequent arguments (if any) are given to the
        # method at invocation time.
        local -r req="${1}"
        shift 1

        # The method body can be anything.
        # The exit code from this method will be propagated to the caller.        
        curl "$($req url)" 2>&1
}

# Create an instance.
req=$(Request "https://www.google.com")

# Invoke a method on the instance.
$req curl