Introduce adopt_foreach

A simple mechanism to iterate through arguments without creating a
parser.

Author: ethomson

adopt.c

@@ -573,6 +573,28 @@ adopt_status_t adopt_parse(
 	return validate_required(opt, specs, given_specs);
 }
 
+int adopt_foreach(
+	const adopt_spec specs[],
+	char **args,
+	size_t args_len,
+	unsigned int flags,
+	int (*callback)(adopt_opt *, void *),
+	void *callback_data)
+{
+	adopt_parser parser;
+	adopt_opt opt;
+	int ret;
+
+	adopt_parser_init(&parser, specs, args, args_len, flags);
+
+	while (adopt_parser_next(&opt, &parser)) {
+		if ((ret = callback(&opt, callback_data)) != 0)
+			return ret;
+	}
+
+	return 0;
+}
+
 static int spec_name_fprint(FILE *file, const adopt_spec *spec)
 {
 	int error;

adopt.h

@@ -293,6 +293,24 @@ adopt_status_t adopt_parse(
     size_t args_len,
     unsigned int flags);
 
+/**
+ * Quickly executes the given callback for each argument.
+ *
+ * @param specs A NULL-terminated array of `adopt_spec`s that can be parsed
+ * @param args The arguments that will be parsed
+ * @param args_len The length of arguments to be parsed
+ * @param flags The `adopt_flag_t flags for parsing
+ * @param callback The callback to invoke for each specified option
+ * @param callback_data Data to be provided to the callback
+ */
+int adopt_foreach(
+	const adopt_spec specs[],
+	char **args,
+	size_t args_len,
+	unsigned int flags,
+	int (*callback)(adopt_opt *, void *),
+	void *callback_data);
+
 /**
  * Initializes a parser that parses the given arguments according to the
  * given specifications.