From c5e2758931d222fb20b552fb2a0d71fe83e8bbc9 Mon Sep 17 00:00:00 2001
From: Matthias Kruk <m@m10k.eu>
Date: Fri, 12 Aug 2022 01:54:00 +0900
Subject: [PATCH] include/opt: Use an associative array to simplify flag
 parsing

When parsing the flags of an option, the opt module uses a case
construct, which looks clumsy, isn't very easy to read, and makes
adding new flags more complicated than need be.

This commit modifies the opt module to use an associative array
to simplify flag parsing. This way, the parser only has to use a
flag as index into the array in order to find out its internal
value.
---
 include/opt.sh | 58 +++++++++++++++++++++++++++++---------------------
 1 file changed, 34 insertions(+), 24 deletions(-)

diff --git a/include/opt.sh b/include/opt.sh
index 0cddf5e..bc844a6 100644
--- a/include/opt.sh
+++ b/include/opt.sh
@@ -24,6 +24,11 @@ __init() {
 	declare -xgir __opt_flag_required=1
 	declare -xgir __opt_flag_has_value=2
 
+	declare -xgAr __opt_flags_map=(
+		["r"]="$__opt_flag_required"
+		["v"]="$__opt_flag_has_value"
+	)
+
 	declare -Axg __opt_short
 	declare -Axg __opt_long
 	declare -Axg __opt_desc
@@ -66,6 +71,31 @@ _opt_is_defined() {
 	return 1
 }
 
+_opt_parse_flags() {
+	local flags="$1"
+
+	local -i parsed_flags
+	local -i i
+
+	for (( i = 0, parsed_flags = 0; i < ${#flags}; i++ )); do
+		local flag_name
+		local flag_value
+
+		flag_name="${flags:$i:1}"
+		flag_value="${__opt_flags_map[$flag_name]}"
+
+		if (( flag_value == 0 )); then
+			log_error "Invalid flag: $flag_name"
+			return 1
+		fi
+
+		(( parsed_flags |= flag_value ))
+	done
+
+	echo "$parsed_flags"
+	return 0
+}
+
 opt_add_arg() {
 	local short="$1"
 	local long="$2"
@@ -75,36 +105,16 @@ opt_add_arg() {
 	local regex="$6"
 	local action="$7"
 
-	local num_flags
-	local bflags
-	local i
+	local -i parsed_flags
 
-	if _opt_is_defined "-$short" "--$long"; then
+	if _opt_is_defined "-$short" "--$long" ||
+	   ! parsed_flags=$(_opt_parse_flags "$flags"); then
 		return 1
 	fi
 
-	num_flags="${#flags}"
-	bflags=0
-
-	for (( i = 0; i < num_flags; i++ )); do
-		case "${flags:$i:1}" in
-			"r")
-				((bflags |= __opt_flag_required))
-				;;
-
-			"v")
-				((bflags |= __opt_flag_has_value))
-				;;
-
-			*)
-				return 1
-				;;
-		esac
-	done
-
 	__opt_short["$long"]="$short"
 	__opt_long["$short"]="$long"
-	__opt_flags["$long"]="$bflags"
+	__opt_flags["$long"]="$parsed_flags"
 	__opt_desc["$long"]="$desc"
 	__opt_regex["$long"]="$regex"
 	__opt_action["$long"]="$action"
-- 
2.47.3