X-Git-Url: http://git.efficios.com/?p=argpar.git;a=blobdiff_plain;f=argpar%2Fargpar.c;h=f324d7fb130355a42ef07583cfcd520f09f2e324;hp=f5275aa755649cde191e5e71807e990e2f85a3cd;hb=f3ab5ca1c03d5ae622ac53b7c1da30ebd21db199;hpb=03e1579f42a13b5e8ccf26bcc55fa5c23ba9f313

diff --git a/argpar/argpar.c b/argpar/argpar.c
index f5275aa..f324d7f 100644
--- a/argpar/argpar.c
+++ b/argpar/argpar.c
@@ -1,7 +1,8 @@
 /*
  * SPDX-License-Identifier: MIT
  *
- * Copyright 2019 Philippe Proulx <pproulx@efficios.com>
+ * Copyright (c) 2019-2021 Philippe Proulx <pproulx@efficios.com>
+ * Copyright (c) 2020-2021 Simon Marchi <simon.marchi@efficios.com>
  */
 
 #include <assert.h>
@@ -13,9 +14,13 @@
 
 #include "argpar.h"
 
-#define argpar_realloc(_ptr, _type, _nmemb) ((_type *) realloc(_ptr, (_nmemb) * sizeof(_type)))
-#define argpar_calloc(_type, _nmemb) ((_type *) calloc((_nmemb), sizeof(_type)))
-#define argpar_zalloc(_type) argpar_calloc(_type, 1)
+#define ARGPAR_REALLOC(_ptr, _type, _nmemb)				\
+	((_type *) realloc(_ptr, (_nmemb) * sizeof(_type)))
+
+#define ARGPAR_CALLOC(_type, _nmemb)					\
+	((_type *) calloc((_nmemb), sizeof(_type)))
+
+#define ARGPAR_ZALLOC(_type) ARGPAR_CALLOC(_type, 1)
 
 #define ARGPAR_ASSERT(_cond) assert(_cond)
 
@@ -25,15 +30,83 @@
 # define ARGPAR_PRINTF_FORMAT printf
 #endif
 
+/*
+ * An argpar iterator.
+ *
+ * Such a structure contains the state of an iterator between calls to
+ * argpar_iter_next().
+ */
+struct argpar_iter {
+	/*
+	 * Data provided by the user to argpar_iter_create(); immutable
+	 * afterwards.
+	 */
+	unsigned int argc;
+	const char * const *argv;
+	const struct argpar_opt_descr *descrs;
+
+	/*
+	 * Index of the argument to process in the next
+	 * argpar_iter_next() call.
+	 */
+	unsigned int i;
+
+	/* Counter of non-option arguments */
+	int non_opt_index;
+
+	/*
+	 * Current character of the current short option group: if it's
+	 * not `NULL`, the parser is in within a short option group,
+	 * therefore it must resume there in the next
+	 * argpar_iter_next() call.
+	 */
+	const char *short_opt_ch;
+};
+
+/* Base parsing item */
+struct argpar_item {
+	enum argpar_item_type type;
+};
+
+/* Option parsing item */
+struct argpar_item_opt {
+	struct argpar_item base;
+
+	/* Corresponding descriptor */
+	const struct argpar_opt_descr *descr;
+
+	/* Argument, or `NULL` if none; owned by this */
+	char *arg;
+};
+
+/* Non-option parsing item */
+struct argpar_item_non_opt {
+	struct argpar_item base;
+
+	/*
+	 * Complete argument, pointing to one of the entries of the
+	 * original arguments (`argv`).
+	 */
+	const char *arg;
+
+	/*
+	 * Index of this argument amongst all original arguments
+	 * (`argv`).
+	 */
+	unsigned int orig_index;
+
+	/* Index of this argument amongst other non-option arguments */
+	unsigned int non_opt_index;
+};
+
 static __attribute__((format(ARGPAR_PRINTF_FORMAT, 1, 0)))
-char *argpar_vasprintf(const char *fmt, va_list args)
+char *argpar_vasprintf(const char * const fmt, va_list args)
 {
 	int len1, len2;
 	char *str;
 	va_list args2;
 
 	va_copy(args2, args);
-
 	len1 = vsnprintf(NULL, 0, fmt, args);
 	if (len1 < 0) {
 		str = NULL;
@@ -46,7 +119,6 @@ char *argpar_vasprintf(const char *fmt, va_list args)
 	}
 
 	len2 = vsnprintf(str, len1 + 1, fmt, args2);
-
 	ARGPAR_ASSERT(len1 == len2);
 
 end:
@@ -56,7 +128,7 @@ end:
 
 
 static __attribute__((format(ARGPAR_PRINTF_FORMAT, 1, 2)))
-char *argpar_asprintf(const char *fmt, ...)
+char *argpar_asprintf(const char * const fmt, ...)
 {
 	va_list args;
 	char *str;
@@ -64,20 +136,23 @@ char *argpar_asprintf(const char *fmt, ...)
 	va_start(args, fmt);
 	str = argpar_vasprintf(fmt, args);
 	va_end(args);
-
 	return str;
 }
 
 static __attribute__((format(ARGPAR_PRINTF_FORMAT, 2, 3)))
-bool argpar_string_append_printf(char **str, const char *fmt, ...)
+bool try_append_string_printf(char ** const str, const char *fmt, ...)
 {
 	char *new_str = NULL;
-	char *addendum;
+	char *addendum = NULL;
 	bool success;
 	va_list args;
 
-	ARGPAR_ASSERT(str);
+	if (!str) {
+		success = true;
+		goto end;
+	}
 
+	ARGPAR_ASSERT(str);
 	va_start(args, fmt);
 	addendum = argpar_vasprintf(fmt, args);
 	va_end(args);
@@ -95,29 +170,78 @@ bool argpar_string_append_printf(char **str, const char *fmt, ...)
 
 	free(*str);
 	*str = new_str;
-
 	success = true;
 
 end:
 	free(addendum);
-
 	return success;
 }
 
-static
-void destroy_item(struct argpar_item * const item)
+ARGPAR_HIDDEN
+enum argpar_item_type argpar_item_type(const struct argpar_item * const item)
+{
+	ARGPAR_ASSERT(item);
+	return item->type;
+}
+
+ARGPAR_HIDDEN
+const struct argpar_opt_descr *argpar_item_opt_descr(
+		const struct argpar_item * const item)
+{
+	ARGPAR_ASSERT(item);
+	ARGPAR_ASSERT(item->type == ARGPAR_ITEM_TYPE_OPT);
+	return ((const struct argpar_item_opt *) item)->descr;
+}
+
+ARGPAR_HIDDEN
+const char *argpar_item_opt_arg(const struct argpar_item * const item)
+{
+	ARGPAR_ASSERT(item);
+	ARGPAR_ASSERT(item->type == ARGPAR_ITEM_TYPE_OPT);
+	return ((const struct argpar_item_opt *) item)->arg;
+}
+
+ARGPAR_HIDDEN
+const char *argpar_item_non_opt_arg(const struct argpar_item * const item)
+{
+	ARGPAR_ASSERT(item);
+	ARGPAR_ASSERT(item->type == ARGPAR_ITEM_TYPE_NON_OPT);
+	return ((const struct argpar_item_non_opt *) item)->arg;
+}
+
+ARGPAR_HIDDEN
+unsigned int argpar_item_non_opt_orig_index(
+		const struct argpar_item * const item)
+{
+	ARGPAR_ASSERT(item);
+	ARGPAR_ASSERT(item->type == ARGPAR_ITEM_TYPE_NON_OPT);
+	return ((const struct argpar_item_non_opt *) item)->orig_index;
+}
+
+ARGPAR_HIDDEN
+unsigned int argpar_item_non_opt_non_opt_index(
+		const struct argpar_item * const item)
+{
+	ARGPAR_ASSERT(item);
+	ARGPAR_ASSERT(item->type == ARGPAR_ITEM_TYPE_NON_OPT);
+	return ((const struct argpar_item_non_opt *) item)->non_opt_index;
+}
+
+ARGPAR_HIDDEN
+void argpar_item_destroy(const struct argpar_item * const item)
 {
 	if (!item) {
 		goto end;
 	}
 
 	if (item->type == ARGPAR_ITEM_TYPE_OPT) {
-		struct argpar_item_opt * const opt_item = (void *) item;
+		struct argpar_item_opt * const opt_item =
+			(struct argpar_item_opt *) item;
 
-		free((void *) opt_item->arg);
+		free(opt_item->arg);
 	}
 
-	free(item);
+	free((void *) item);
 
 end:
 	return;
@@ -125,7 +249,7 @@ end:
 
 static
 bool push_item(struct argpar_item_array * const array,
-		struct argpar_item * const item)
+		const struct argpar_item * const item)
 {
 	bool success;
 
@@ -133,11 +257,10 @@ bool push_item(struct argpar_item_array * const array,
 	ARGPAR_ASSERT(item);
 
 	if (array->n_items == array->n_alloc) {
-		unsigned int new_n_alloc = array->n_alloc * 2;
-		struct argpar_item **new_items;
-
-		new_items = argpar_realloc(array->items,
-			struct argpar_item *, new_n_alloc);
+		const unsigned int new_n_alloc = array->n_alloc * 2;
+		const struct argpar_item ** const new_items =
+			ARGPAR_REALLOC(array->items, const struct argpar_item *,
+				new_n_alloc);
 		if (!new_items) {
 			success = false;
 			goto end;
@@ -149,7 +272,6 @@ bool push_item(struct argpar_item_array * const array,
 
 	array->items[array->n_items] = item;
 	array->n_items++;
-
 	success = true;
 
 end:
@@ -163,7 +285,7 @@ void destroy_item_array(struct argpar_item_array * const array)
 		unsigned int i;
 
 		for (i = 0; i < array->n_items; i++) {
-			destroy_item(array->items[i]);
+			argpar_item_destroy(array->items[i]);
 		}
 
 		free(array->items);
@@ -172,23 +294,22 @@ void destroy_item_array(struct argpar_item_array * const array)
 }
 
 static
-struct argpar_item_array *new_item_array(void)
+struct argpar_item_array *create_item_array(void)
 {
 	struct argpar_item_array *ret;
 	const int initial_size = 10;
 
-	ret = argpar_zalloc(struct argpar_item_array);
+	ret = ARGPAR_ZALLOC(struct argpar_item_array);
 	if (!ret) {
 		goto end;
 	}
 
-	ret->items = argpar_calloc(struct argpar_item *, initial_size);
+	ret->items = ARGPAR_CALLOC(const struct argpar_item *, initial_size);
 	if (!ret->items) {
 		goto error;
 	}
 
 	ret->n_alloc = initial_size;
-
 	goto end;
 
 error:
@@ -205,7 +326,7 @@ struct argpar_item_opt *create_opt_item(
 		const char * const arg)
 {
 	struct argpar_item_opt *opt_item =
-		argpar_zalloc(struct argpar_item_opt);
+		ARGPAR_ZALLOC(struct argpar_item_opt);
 
 	if (!opt_item) {
 		goto end;
@@ -224,7 +345,7 @@ struct argpar_item_opt *create_opt_item(
 	goto end;
 
 error:
-	destroy_item(&opt_item->base);
+	argpar_item_destroy(&opt_item->base);
 	opt_item = NULL;
 
 end:
@@ -237,7 +358,7 @@ struct argpar_item_non_opt *create_non_opt_item(const char * const arg,
 		const unsigned int non_opt_index)
 {
 	struct argpar_item_non_opt * const non_opt_item =
-		argpar_zalloc(struct argpar_item_non_opt);
+		ARGPAR_ZALLOC(struct argpar_item_non_opt);
 
 	if (!non_opt_item) {
 		goto end;
@@ -277,88 +398,95 @@ end:
 
 enum parse_orig_arg_opt_ret {
 	PARSE_ORIG_ARG_OPT_RET_OK,
-	PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT = -2,
-	PARSE_ORIG_ARG_OPT_RET_ERROR = -1,
+	PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT = -1,
+	PARSE_ORIG_ARG_OPT_RET_ERROR_MISSING_OPT_ARG = -2,
+	PARSE_ORIG_ARG_OPT_RET_ERROR_INVALID_ARG = -3,
+	PARSE_ORIG_ARG_OPT_RET_ERROR_UNEXPECTED_OPT_ARG = -4,
+	PARSE_ORIG_ARG_OPT_RET_ERROR_MEMORY = -5,
 };
 
 static
 enum parse_orig_arg_opt_ret parse_short_opts(const char * const short_opts,
 		const char * const next_orig_arg,
 		const struct argpar_opt_descr * const descrs,
-		struct argpar_parse_ret * const parse_ret,
-		bool * const used_next_orig_arg)
+		struct argpar_iter * const iter,
+		char ** const error, struct argpar_item ** const item)
 {
 	enum parse_orig_arg_opt_ret ret = PARSE_ORIG_ARG_OPT_RET_OK;
-	const char *short_opt_ch = short_opts;
+	bool used_next_orig_arg = false;
+	const char *opt_arg = NULL;
+	const struct argpar_opt_descr *descr;
+	struct argpar_item_opt *opt_item;
 
 	if (strlen(short_opts) == 0) {
-		argpar_string_append_printf(&parse_ret->error, "Invalid argument");
+		try_append_string_printf(error, "Invalid argument");
+		ret = PARSE_ORIG_ARG_OPT_RET_ERROR_INVALID_ARG;
 		goto error;
 	}
 
-	while (*short_opt_ch) {
-		const char *opt_arg = NULL;
-		const struct argpar_opt_descr *descr;
-		struct argpar_item_opt *opt_item;
-
-		/* Find corresponding option descriptor */
-		descr = find_descr(descrs, *short_opt_ch, NULL);
-		if (!descr) {
-			ret = PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT;
-			argpar_string_append_printf(&parse_ret->error,
-				"Unknown option `-%c`", *short_opt_ch);
-			goto error;
-		}
+	if (!iter->short_opt_ch) {
+		iter->short_opt_ch = short_opts;
+	}
 
-		if (descr->with_arg) {
-			if (short_opt_ch[1]) {
-				/* `-oarg` form */
-				opt_arg = &short_opt_ch[1];
-			} else {
-				/* `-o arg` form */
-				opt_arg = next_orig_arg;
-				*used_next_orig_arg = true;
-			}
+	/* Find corresponding option descriptor */
+	descr = find_descr(descrs, *iter->short_opt_ch, NULL);
+	if (!descr) {
+		try_append_string_printf(error, "Unknown option `-%c`",
+			*iter->short_opt_ch);
+		ret = PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT;
+		goto error;
+	}
 
-			/*
-			 * We accept `-o ''` (empty option's argument),
-			 * but not `-o` alone if an option's argument is
-			 * expected.
-			 */
-			if (!opt_arg || (short_opt_ch[1] && strlen(opt_arg) == 0)) {
-				argpar_string_append_printf(&parse_ret->error,
-					"Missing required argument for option `-%c`",
-					*short_opt_ch);
-				*used_next_orig_arg = false;
-				goto error;
-			}
+	if (descr->with_arg) {
+		if (iter->short_opt_ch[1]) {
+			/* `-oarg` form */
+			opt_arg = &iter->short_opt_ch[1];
+		} else {
+			/* `-o arg` form */
+			opt_arg = next_orig_arg;
+			used_next_orig_arg = true;
 		}
 
-		/* Create and append option argument */
-		opt_item = create_opt_item(descr, opt_arg);
-		if (!opt_item) {
+		/*
+		 * We accept `-o ''` (empty option argument), but not
+		 * `-o` alone if an option argument is expected.
+		 */
+		if (!opt_arg || (iter->short_opt_ch[1] &&
+				strlen(opt_arg) == 0)) {
+			try_append_string_printf(error,
+				"Missing required argument for option `-%c`",
+				*iter->short_opt_ch);
+			used_next_orig_arg = false;
+			ret = PARSE_ORIG_ARG_OPT_RET_ERROR_MISSING_OPT_ARG;
 			goto error;
 		}
+	}
 
-		if (!push_item(parse_ret->items, &opt_item->base)) {
-			goto error;
-		}
+	/* Create and append option argument */
+	opt_item = create_opt_item(descr, opt_arg);
+	if (!opt_item) {
+		ret = PARSE_ORIG_ARG_OPT_RET_ERROR_MEMORY;
+		goto error;
+	}
 
-		if (descr->with_arg) {
-			/* Option has an argument: no more options */
-			break;
-		}
+	*item = &opt_item->base;
+	iter->short_opt_ch++;
 
-		/* Go to next short option */
-		short_opt_ch++;
+	if (descr->with_arg || !*iter->short_opt_ch) {
+		/* Option has an argument: no more options */
+		iter->short_opt_ch = NULL;
+
+		if (used_next_orig_arg) {
+			iter->i += 2;
+		} else {
+			iter->i++;
+		}
 	}
 
 	goto end;
 
 error:
-	if (ret == PARSE_ORIG_ARG_OPT_RET_OK) {
-		ret = PARSE_ORIG_ARG_OPT_RET_ERROR;
-	}
+	ARGPAR_ASSERT(ret != PARSE_ORIG_ARG_OPT_RET_OK);
 
 end:
 	return ret;
@@ -368,13 +496,14 @@ static
 enum parse_orig_arg_opt_ret parse_long_opt(const char * const long_opt_arg,
 		const char * const next_orig_arg,
 		const struct argpar_opt_descr * const descrs,
-		struct argpar_parse_ret * const parse_ret,
-		bool * const used_next_orig_arg)
+		struct argpar_iter * const iter,
+		char ** const error, struct argpar_item ** const item)
 {
 	const size_t max_len = 127;
 	enum parse_orig_arg_opt_ret ret = PARSE_ORIG_ARG_OPT_RET_OK;
 	const struct argpar_opt_descr *descr;
 	struct argpar_item_opt *opt_item;
+	bool used_next_orig_arg = false;
 
 	/* Option's argument, if any */
 	const char *opt_arg = NULL;
@@ -389,8 +518,8 @@ enum parse_orig_arg_opt_ret parse_long_opt(const char * const long_opt_arg,
 	const char *long_opt_name = long_opt_arg;
 
 	if (strlen(long_opt_arg) == 0) {
-		argpar_string_append_printf(&parse_ret->error,
-			"Invalid argument");
+		try_append_string_printf(error, "Invalid argument");
+		ret = PARSE_ORIG_ARG_OPT_RET_ERROR_INVALID_ARG;
 		goto error;
 	}
 
@@ -401,8 +530,9 @@ enum parse_orig_arg_opt_ret parse_long_opt(const char * const long_opt_arg,
 
 		/* Isolate the option name */
 		if (long_opt_name_size > max_len) {
-			argpar_string_append_printf(&parse_ret->error,
+			try_append_string_printf(error,
 				"Invalid argument `--%s`", long_opt_arg);
+			ret = PARSE_ORIG_ARG_OPT_RET_ERROR_INVALID_ARG;
 			goto error;
 		}
 
@@ -414,8 +544,8 @@ enum parse_orig_arg_opt_ret parse_long_opt(const char * const long_opt_arg,
 	/* Find corresponding option descriptor */
 	descr = find_descr(descrs, '\0', long_opt_name);
 	if (!descr) {
-		argpar_string_append_printf(&parse_ret->error,
-			"Unknown option `--%s`", long_opt_name);
+		try_append_string_printf(error, "Unknown option `--%s`",
+			long_opt_name);
 		ret = PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT;
 		goto error;
 	}
@@ -428,23 +558,24 @@ enum parse_orig_arg_opt_ret parse_long_opt(const char * const long_opt_arg,
 		} else {
 			/* `--long-opt arg` style */
 			if (!next_orig_arg) {
-				argpar_string_append_printf(&parse_ret->error,
+				try_append_string_printf(error,
 					"Missing required argument for option `--%s`",
 					long_opt_name);
+				ret = PARSE_ORIG_ARG_OPT_RET_ERROR_MISSING_OPT_ARG;
 				goto error;
 			}
 
 			opt_arg = next_orig_arg;
-			*used_next_orig_arg = true;
+			used_next_orig_arg = true;
 		}
 	} else if (eq_pos) {
 		/*
 		 * Unexpected `--opt=arg` style for a long option which
 		 * doesn't accept an argument.
 		 */
-		argpar_string_append_printf(&parse_ret->error,
-			"Unexpected argument for option `--%s`",
-			long_opt_name);
+		try_append_string_printf(error,
+			"Unexpected argument for option `--%s`", long_opt_name);
+		ret = PARSE_ORIG_ARG_OPT_RET_ERROR_UNEXPECTED_OPT_ARG;
 		goto error;
 	}
 
@@ -454,16 +585,17 @@ enum parse_orig_arg_opt_ret parse_long_opt(const char * const long_opt_arg,
 		goto error;
 	}
 
-	if (!push_item(parse_ret->items, &opt_item->base)) {
-		goto error;
+	if (used_next_orig_arg) {
+		iter->i += 2;
+	} else {
+		iter->i++;
 	}
 
+	*item = &opt_item->base;
 	goto end;
 
 error:
-	if (ret == PARSE_ORIG_ARG_OPT_RET_OK) {
-		ret = PARSE_ORIG_ARG_OPT_RET_ERROR;
-	}
+	ARGPAR_ASSERT(ret != PARSE_ORIG_ARG_OPT_RET_OK);
 
 end:
 	return ret;
@@ -473,8 +605,8 @@ static
 enum parse_orig_arg_opt_ret parse_orig_arg_opt(const char * const orig_arg,
 		const char * const next_orig_arg,
 		const struct argpar_opt_descr * const descrs,
-		struct argpar_parse_ret * const parse_ret,
-		bool * const used_next_orig_arg)
+		struct argpar_iter * const iter, char ** const error,
+		struct argpar_item ** const item)
 {
 	enum parse_orig_arg_opt_ret ret = PARSE_ORIG_ARG_OPT_RET_OK;
 
@@ -483,28 +615,29 @@ enum parse_orig_arg_opt_ret parse_orig_arg_opt(const char * const orig_arg,
 	if (orig_arg[1] == '-') {
 		/* Long option */
 		ret = parse_long_opt(&orig_arg[2],
-			next_orig_arg, descrs, parse_ret,
-			used_next_orig_arg);
+			next_orig_arg, descrs, iter, error, item);
 	} else {
 		/* Short option */
 		ret = parse_short_opts(&orig_arg[1],
-			next_orig_arg, descrs, parse_ret,
-			used_next_orig_arg);
+			next_orig_arg, descrs, iter, error, item);
 	}
 
 	return ret;
 }
 
 static
-bool prepend_while_parsing_arg_to_error(char **error,
+bool try_prepend_while_parsing_arg_to_error(char ** const error,
 		const unsigned int i, const char * const arg)
 {
 	char *new_error;
 	bool success;
 
-	ARGPAR_ASSERT(error);
-	ARGPAR_ASSERT(*error);
+	if (!error) {
+		success = true;
+		goto end;
+	}
 
+	ARGPAR_ASSERT(*error);
 	new_error = argpar_asprintf("While parsing argument #%u (`%s`): %s",
 		i + 1, arg, *error);
 	if (!new_error) {
@@ -521,104 +654,206 @@ end:
 }
 
 ARGPAR_HIDDEN
-struct argpar_parse_ret argpar_parse(unsigned int argc,
-		const char * const *argv,
-		const struct argpar_opt_descr * const descrs,
-		bool fail_on_unknown_opt)
+struct argpar_iter *argpar_iter_create(const unsigned int argc,
+		const char * const * const argv,
+		const struct argpar_opt_descr * const descrs)
 {
-	struct argpar_parse_ret parse_ret = { 0 };
-	unsigned int i;
-	unsigned int non_opt_index = 0;
+	struct argpar_iter * const iter = ARGPAR_ZALLOC(struct argpar_iter);
 
-	parse_ret.items = new_item_array();
-	if (!parse_ret.items) {
-		goto error;
+	if (!iter) {
+		goto end;
 	}
 
-	for (i = 0; i < argc; i++) {
-		enum parse_orig_arg_opt_ret parse_orig_arg_opt_ret;
-		bool used_next_orig_arg = false;
-		const char * const orig_arg = argv[i];
-		const char * const next_orig_arg =
-			i < argc - 1 ? argv[i + 1] : NULL;
+	iter->argc = argc;
+	iter->argv = argv;
+	iter->descrs = descrs;
 
-		if (orig_arg[0] != '-') {
-			/* Non-option argument */
-			struct argpar_item_non_opt *non_opt_item =
-				create_non_opt_item(orig_arg, i, non_opt_index);
+end:
+	return iter;
+}
 
-			if (!non_opt_item) {
-				goto error;
-			}
+ARGPAR_HIDDEN
+void argpar_iter_destroy(struct argpar_iter * const iter)
+{
+	free(iter);
+}
+
+ARGPAR_HIDDEN
+enum argpar_iter_next_status argpar_iter_next(
+		struct argpar_iter * const iter,
+		const struct argpar_item ** const item, char ** const error)
+{
+	enum argpar_iter_next_status status;
+	enum parse_orig_arg_opt_ret parse_orig_arg_opt_ret;
+	const char *orig_arg;
+	const char *next_orig_arg;
 
-			non_opt_index++;
+	ARGPAR_ASSERT(iter->i <= iter->argc);
 
-			if (!push_item(parse_ret.items, &non_opt_item->base)) {
-				goto error;
-			}
+	if (error) {
+		*error = NULL;
+	}
 
-			continue;
+	if (iter->i == iter->argc) {
+		status = ARGPAR_ITER_NEXT_STATUS_END;
+		goto end;
+	}
+
+	orig_arg = iter->argv[iter->i];
+	next_orig_arg =
+		iter->i < (iter->argc - 1) ? iter->argv[iter->i + 1] : NULL;
+
+	if (orig_arg[0] != '-') {
+		/* Non-option argument */
+		struct argpar_item_non_opt * const non_opt_item =
+			create_non_opt_item(orig_arg, iter->i,
+				iter->non_opt_index);
+
+		if (!non_opt_item) {
+			status = ARGPAR_ITER_NEXT_STATUS_ERROR_MEMORY;
+			goto end;
 		}
 
-		/* Option argument */
-		parse_orig_arg_opt_ret = parse_orig_arg_opt(orig_arg,
-			next_orig_arg, descrs, &parse_ret, &used_next_orig_arg);
+		iter->non_opt_index++;
+		iter->i++;
+		*item = &non_opt_item->base;
+		status = ARGPAR_ITER_NEXT_STATUS_OK;
+		goto end;
+	}
+
+	/* Option argument */
+	parse_orig_arg_opt_ret = parse_orig_arg_opt(orig_arg,
+		next_orig_arg, iter->descrs, iter, error,
+		(struct argpar_item **) item);
+	switch (parse_orig_arg_opt_ret) {
+	case PARSE_ORIG_ARG_OPT_RET_OK:
+		status = ARGPAR_ITER_NEXT_STATUS_OK;
+		break;
+	case PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT:
+	case PARSE_ORIG_ARG_OPT_RET_ERROR_MISSING_OPT_ARG:
+	case PARSE_ORIG_ARG_OPT_RET_ERROR_INVALID_ARG:
+	case PARSE_ORIG_ARG_OPT_RET_ERROR_UNEXPECTED_OPT_ARG:
+		try_prepend_while_parsing_arg_to_error(error, iter->i,
+			orig_arg);
+
 		switch (parse_orig_arg_opt_ret) {
-		case PARSE_ORIG_ARG_OPT_RET_OK:
-			break;
 		case PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT:
-			ARGPAR_ASSERT(!used_next_orig_arg);
+			status = ARGPAR_ITER_NEXT_STATUS_ERROR_UNKNOWN_OPT;
+			break;
+		case PARSE_ORIG_ARG_OPT_RET_ERROR_MISSING_OPT_ARG:
+			status = ARGPAR_ITER_NEXT_STATUS_ERROR_MISSING_OPT_ARG;
+			break;
+		case PARSE_ORIG_ARG_OPT_RET_ERROR_INVALID_ARG:
+			status = ARGPAR_ITER_NEXT_STATUS_ERROR_INVALID_ARG;
+			break;
+		case PARSE_ORIG_ARG_OPT_RET_ERROR_UNEXPECTED_OPT_ARG:
+			status = ARGPAR_ITER_NEXT_STATUS_ERROR_UNEXPECTED_OPT_ARG;
+			break;
+		default:
+			abort();
+		}
 
+		break;
+	case PARSE_ORIG_ARG_OPT_RET_ERROR_MEMORY:
+		status = ARGPAR_ITER_NEXT_STATUS_ERROR_MEMORY;
+		break;
+	default:
+		abort();
+	}
+
+end:
+	return status;
+}
+
+ARGPAR_HIDDEN
+unsigned int argpar_iter_ingested_orig_args(
+		const struct argpar_iter * const iter)
+{
+	return iter->i;
+}
+
+ARGPAR_HIDDEN
+struct argpar_parse_ret argpar_parse(const unsigned int argc,
+		const char * const * const argv,
+		const struct argpar_opt_descr * const descrs,
+		const bool fail_on_unknown_opt)
+{
+	struct argpar_parse_ret parse_ret = { 0 };
+	const struct argpar_item *item = NULL;
+	struct argpar_iter *iter = NULL;
+
+	parse_ret.items = create_item_array();
+	if (!parse_ret.items) {
+		parse_ret.error = strdup("Failed to create items array.");
+		ARGPAR_ASSERT(parse_ret.error);
+		goto error;
+	}
+
+	iter = argpar_iter_create(argc, argv, descrs);
+	if (!iter) {
+		parse_ret.error = strdup("Failed to create argpar iter.");
+		ARGPAR_ASSERT(parse_ret.error);
+		goto error;
+	}
+
+	while (true) {
+		const enum argpar_iter_next_status status =
+			argpar_iter_next(iter, &item, &parse_ret.error);
+
+		switch (status) {
+		case ARGPAR_ITER_NEXT_STATUS_ERROR_MISSING_OPT_ARG:
+		case ARGPAR_ITER_NEXT_STATUS_ERROR_INVALID_ARG:
+		case ARGPAR_ITER_NEXT_STATUS_ERROR_UNEXPECTED_OPT_ARG:
+		case ARGPAR_ITER_NEXT_STATUS_ERROR_MEMORY:
+			goto error;
+		case ARGPAR_ITER_NEXT_STATUS_ERROR_UNKNOWN_OPT:
 			if (fail_on_unknown_opt) {
-				prepend_while_parsing_arg_to_error(
-					&parse_ret.error, i, orig_arg);
+				parse_ret.ingested_orig_args =
+					argpar_iter_ingested_orig_args(iter);
 				goto error;
 			}
 
-			/*
-			 * The current original argument is not
-			 * considered ingested because it triggered an
-			 * unknown option.
-			 */
-			parse_ret.ingested_orig_args = i;
 			free(parse_ret.error);
 			parse_ret.error = NULL;
-			goto end;
-		case PARSE_ORIG_ARG_OPT_RET_ERROR:
-			prepend_while_parsing_arg_to_error(
-				&parse_ret.error, i, orig_arg);
-			goto error;
+			goto success;
+		case ARGPAR_ITER_NEXT_STATUS_END:
+			goto success;
 		default:
-			abort();
+			ARGPAR_ASSERT(status == ARGPAR_ITER_NEXT_STATUS_OK);
+			break;
 		}
 
-		if (used_next_orig_arg) {
-			i++;
+		if (!push_item(parse_ret.items, item)) {
+			goto error;
 		}
+
+		item = NULL;
 	}
 
-	parse_ret.ingested_orig_args = argc;
-	free(parse_ret.error);
-	parse_ret.error = NULL;
+success:
+	ARGPAR_ASSERT(!parse_ret.error);
+	parse_ret.ingested_orig_args = argpar_iter_ingested_orig_args(iter);
 	goto end;
 
 error:
-	/* That's how we indicate that an error occured */
+	ARGPAR_ASSERT(parse_ret.error);
+
+	/* That's how we indicate that an error occurred */
 	destroy_item_array(parse_ret.items);
 	parse_ret.items = NULL;
 
 end:
+	argpar_iter_destroy(iter);
+	argpar_item_destroy(item);
 	return parse_ret;
 }
 
 ARGPAR_HIDDEN
-void argpar_parse_ret_fini(struct argpar_parse_ret *ret)
+void argpar_parse_ret_fini(struct argpar_parse_ret * const ret)
 {
 	ARGPAR_ASSERT(ret);
-
 	destroy_item_array(ret->items);
 	ret->items = NULL;
-
 	free(ret->error);
 	ret->error = NULL;
 }