Dorothy: intersect and complement prototypes

complement.bash

# remove the items from <remove-array-var-name> from <array-var-name>:
# __complement <array-var-name> <remove-array-var-name>
# remove the <remove-needle>s from <array-var-name>:
# __complement <array-var-name> -- ..<remove-needle>
# function __complement {
# 	local array_var_name_left="$1" array_var_name_right n_left n_right i_left v_left i_right found result=()
# 	shift
# 	# trunk-ignore(shellcheck/SC1087)
# 	eval "n_left=\${#$array_var_name_left[@]}"
# 	if [[ $1 == '--' ]]; then
# 		shift
# 		local args=("$@")
# 		array_var_name_right='args'
# 	else
# 		array_var_name_right="$2"
# 	fi
# 	# trunk-ignore(shellcheck/SC1087)
# 	eval "n_right=\${#$array_var_name_right[@]}"
# 	for ((i_left = 0; i_left < n_left; ++i_left)); do
# 		for ((i_right = 0; i_right < n_right; ++i_right)); do
# 			eval "v_left=\${$array_var_name_left[i_left]}"
# 			if eval "[[ \$v_left != \"\${$array_var_name_right[i_right]}\" ]]"; then
# 				result+=("$v_left")
# 			fi
# 		done
# 	done
# 	eval "$array_var_name_left=(\${result[@]})"
# }

gistfile1.txt

# __intersect <array-var-name> <array-var-name>
function __intersect {
	local array_var_name_left="$1" array_var_name_right="$2" n_left n_right i_left i_right
	# trunk-ignore(shellcheck/SC1087)
	eval "n_left=\${#$array_var_name_left[@]}"
	# trunk-ignore(shellcheck/SC1087)
	eval "n_right=\${#$array_var_name_right[@]}"
	for ((i_left = 0; i_left < n_left; ++i_left)); do
		for ((i_right = 0; i_right < n_right; ++i_right)); do
			if eval "[[ \"\${$array_var_name_left[i]}\" == \"\${$array_var_name_right[i]}\" ]]"; then
				eval "__print_lines \"\${$array_var_name_left[i]}\""
				break
			fi
		done
	done
}

# there is a __remove_needles in balupton's dotfiles
# __complement <array-var-name> <array-var-name>
function __complement {
	local array_var_name_left="$1" array_var_name_right="$2" n_left n_right i_left i_right found
	# trunk-ignore(shellcheck/SC1087)
	eval "n_left=\${#$array_var_name_left[@]}"
	# trunk-ignore(shellcheck/SC1087)
	eval "n_right=\${#$array_var_name_right[@]}"
	for ((i_left = 0; i_left < n_left; ++i_left)); do
		found='no'
		for ((i_right = 0; i_right < n_right; ++i_right)); do
			if eval "[[ \"\${$array_var_name_left[i]}\" == \"\${$array_var_name_right[i]}\" ]]"; then
				found='yes'
				break
			fi
		done
		if [[ $found == 'no' ]]; then
			eval "__print_lines \"\${$array_var_name_left[i]}\""
		fi
	done
}