X-Git-Url: http://git.efficios.com/?p=argpar.git;a=blobdiff_plain;f=argpar%2Fargpar.c;h=82b561ceaae707002f36754c55e828d35b882206;hp=13f66812894037b669924eb4446fd3f5472e464b;hb=143cec42e14e050571be640cb2dfa5c5e0198d59;hpb=1ae22b5e8335dfe14b805404a16b90817f1a99e1

diff --git a/argpar/argpar.c b/argpar/argpar.c
index 13f6681..82b561c 100644
--- a/argpar/argpar.c
+++ b/argpar/argpar.c
@@ -1,26 +1,10 @@
 /*
- * Copyright 2019 Philippe Proulx <pproulx@efficios.com>
+ * SPDX-License-Identifier: MIT
  *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
+ * Copyright (c) 2019-2021 Philippe Proulx <pproulx@efficios.com>
+ * Copyright (c) 2020-2021 Simon Marchi <simon.marchi@efficios.com>
  */
 
-#include <assert.h>
 #include <stdarg.h>
 #include <stdbool.h>
 #include <stdio.h>
@@ -29,199 +13,203 @@
 
 #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_ASSERT(_cond) assert(_cond)
+#define ARGPAR_ZALLOC(_type) ARGPAR_CALLOC(_type, 1)
 
-#ifdef __MINGW_PRINTF_FORMAT
-# define ARGPAR_PRINTF_FORMAT __MINGW_PRINTF_FORMAT
+#ifdef NDEBUG
+/*
+ * Force usage of the assertion condition to prevent unused variable warnings
+ * when `assert()` are disabled by the `NDEBUG` definition.
+ */
+# define ARGPAR_ASSERT(_cond) ((void) sizeof((void) (_cond), 0))
 #else
-# define ARGPAR_PRINTF_FORMAT printf
+# include <assert.h>
+# define ARGPAR_ASSERT(_cond) assert(_cond)
 #endif
 
-static __attribute__((format(ARGPAR_PRINTF_FORMAT, 1, 0)))
-char *argpar_vasprintf(const char *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;
-		goto end;
-	}
-
-	str = malloc(len1 + 1);
-	if (!str) {
-		goto end;
-	}
-
-	len2 = vsnprintf(str, len1 + 1, fmt, args2);
+/*
+ * 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.
+	 */
+	struct {
+		unsigned int argc;
+		const char * const *argv;
+		const struct argpar_opt_descr *descrs;
+	} user;
+
+	/*
+	 * Index of the argument to process in the next
+	 * argpar_iter_next() call.
+	 */
+	unsigned int i;
 
-	ARGPAR_ASSERT(len1 == len2);
+	/* Counter of non-option arguments */
+	int non_opt_index;
+
+	/*
+	 * Current character within the current short option group: if
+	 * it's not `NULL`, the parser is within a short option group,
+	 * therefore it must resume there in the next argpar_iter_next()
+	 * call.
+	 */
+	const char *short_opt_group_ch;
+
+	/* Temporary character buffer which only grows */
+	struct {
+		size_t size;
+		char *data;
+	} tmp_buf;
+};
 
-end:
-	va_end(args2);
-	return str;
-}
+/* Base parsing item */
+struct argpar_item {
+	enum argpar_item_type type;
+};
 
+/* Option parsing item */
+struct argpar_item_opt {
+	struct argpar_item base;
 
-static __attribute__((format(ARGPAR_PRINTF_FORMAT, 1, 2)))
-char *argpar_asprintf(const char *fmt, ...)
-{
-	va_list args;
-	char *str;
+	/* Corresponding descriptor */
+	const struct argpar_opt_descr *descr;
 
-	va_start(args, fmt);
-	str = argpar_vasprintf(fmt, args);
-	va_end(args);
+	/* Argument, or `NULL` if none; owned by this */
+	char *arg;
+};
 
-	return str;
-}
+/* Non-option parsing item */
+struct argpar_item_non_opt {
+	struct argpar_item base;
 
-static __attribute__((format(ARGPAR_PRINTF_FORMAT, 2, 3)))
-bool argpar_string_append_printf(char **str, const char *fmt, ...)
-{
-	char *new_str = NULL;
-	char *addendum;
-	bool success;
-	va_list args;
+	/*
+	 * Complete argument, pointing to one of the entries of the
+	 * original arguments (`argv`).
+	 */
+	const char *arg;
 
-	ARGPAR_ASSERT(str);
+	/*
+	 * Index of this argument amongst all original arguments
+	 * (`argv`).
+	 */
+	unsigned int orig_index;
 
-	va_start(args, fmt);
-	addendum = argpar_vasprintf(fmt, args);
-	va_end(args);
+	/* Index of this argument amongst other non-option arguments */
+	unsigned int non_opt_index;
+};
 
-	if (!addendum) {
-		success = false;
-		goto end;
-	}
+/* Parsing error */
+struct argpar_error {
+	/* Error type */
+	enum argpar_error_type type;
 
-	new_str = argpar_asprintf("%s%s", *str ? *str : "", addendum);
-	if (!new_str) {
-		success = false;
-		goto end;
-	}
+	/* Original argument index */
+	unsigned int orig_index;
 
-	free(*str);
-	*str = new_str;
+	/* Name of unknown option; owned by this */
+	char *unknown_opt_name;
 
-	success = true;
+	/* Option descriptor */
+	const struct argpar_opt_descr *opt_descr;
 
-end:
-	free(addendum);
+	/* `true` if a short option caused the error */
+	bool is_short;
+};
 
-	return success;
+ARGPAR_HIDDEN
+enum argpar_item_type argpar_item_type(const struct argpar_item * const item)
+{
+	ARGPAR_ASSERT(item);
+	return item->type;
 }
 
-static
-void destroy_item(struct argpar_item * const item)
+ARGPAR_HIDDEN
+const struct argpar_opt_descr *argpar_item_opt_descr(
+		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;
-
-		free((void *) opt_item->arg);
-	}
-
-	free(item);
-
-end:
-	return;
+	ARGPAR_ASSERT(item);
+	ARGPAR_ASSERT(item->type == ARGPAR_ITEM_TYPE_OPT);
+	return ((const struct argpar_item_opt *) item)->descr;
 }
 
-static
-bool push_item(struct argpar_item_array * const array,
-		struct argpar_item * const item)
+ARGPAR_HIDDEN
+const char *argpar_item_opt_arg(const struct argpar_item * const item)
 {
-	bool success;
-
-	ARGPAR_ASSERT(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);
-		if (!new_items) {
-			success = false;
-			goto end;
-		}
-
-		array->n_alloc = new_n_alloc;
-		array->items = new_items;
-	}
-
-	array->items[array->n_items] = item;
-	array->n_items++;
-
-	success = true;
-
-end:
-	return success;
+	ARGPAR_ASSERT(item->type == ARGPAR_ITEM_TYPE_OPT);
+	return ((const struct argpar_item_opt *) item)->arg;
 }
 
-static
-void destroy_item_array(struct argpar_item_array * const array)
+ARGPAR_HIDDEN
+const char *argpar_item_non_opt_arg(const struct argpar_item * const item)
 {
-	if (array) {
-		unsigned int i;
-
-		for (i = 0; i < array->n_items; i++) {
-			destroy_item(array->items[i]);
-		}
+	ARGPAR_ASSERT(item);
+	ARGPAR_ASSERT(item->type == ARGPAR_ITEM_TYPE_NON_OPT);
+	return ((const struct argpar_item_non_opt *) item)->arg;
+}
 
-		free(array->items);
-		free(array);
-	}
+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;
 }
 
-static
-struct argpar_item_array *new_item_array(void)
+ARGPAR_HIDDEN
+unsigned int argpar_item_non_opt_non_opt_index(
+		const struct argpar_item * const item)
 {
-	struct argpar_item_array *ret;
-	const int initial_size = 10;
+	ARGPAR_ASSERT(item);
+	ARGPAR_ASSERT(item->type == ARGPAR_ITEM_TYPE_NON_OPT);
+	return ((const struct argpar_item_non_opt *) item)->non_opt_index;
+}
 
-	ret = argpar_zalloc(struct argpar_item_array);
-	if (!ret) {
+ARGPAR_HIDDEN
+void argpar_item_destroy(const struct argpar_item * const item)
+{
+	if (!item) {
 		goto end;
 	}
 
-	ret->items = argpar_calloc(struct argpar_item *, initial_size);
-	if (!ret->items) {
-		goto error;
-	}
-
-	ret->n_alloc = initial_size;
+	if (item->type == ARGPAR_ITEM_TYPE_OPT) {
+		struct argpar_item_opt * const opt_item =
+			(struct argpar_item_opt *) item;
 
-	goto end;
+		free(opt_item->arg);
+	}
 
-error:
-	destroy_item_array(ret);
-	ret = NULL;
+	free((void *) item);
 
 end:
-	return ret;
+	return;
 }
 
+/*
+ * Creates and returns an option parsing item for the descriptor `descr`
+ * and having the argument `arg` (copied; may be `NULL`).
+ *
+ * Returns `NULL` on memory error.
+ */
 static
 struct argpar_item_opt *create_opt_item(
 		const struct argpar_opt_descr * const descr,
 		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;
@@ -240,20 +228,27 @@ 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:
 	return opt_item;
 }
 
+/*
+ * Creates and returns a non-option parsing item for the original
+ * argument `arg` having the original index `orig_index` and the
+ * non-option index `non_opt_index`.
+ *
+ * Returns `NULL` on memory error.
+ */
 static
 struct argpar_item_non_opt *create_non_opt_item(const char * const arg,
 		const unsigned int orig_index,
 		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;
@@ -268,6 +263,126 @@ end:
 	return non_opt_item;
 }
 
+/*
+ * If `error` is not `NULL`, sets the error `error` to a new parsing
+ * error object, setting its `unknown_opt_name`, `opt_descr`, and
+ * `is_short` members from the parameters.
+ *
+ * `unknown_opt_name` is the unknown option name without any `-` or `--`
+ * prefix: `is_short` controls which type of unknown option it is.
+ *
+ * Returns 0 on success (including if `error` is `NULL`) or -1 on memory
+ * error.
+ */
+static
+int set_error(struct argpar_error ** const error,
+		enum argpar_error_type type,
+		const char * const unknown_opt_name,
+		const struct argpar_opt_descr * const opt_descr,
+		const bool is_short)
+{
+	int ret = 0;
+
+	if (!error) {
+		goto end;
+	}
+
+	*error = ARGPAR_ZALLOC(struct argpar_error);
+	if (!*error) {
+		goto error;
+	}
+
+	(*error)->type = type;
+
+	if (unknown_opt_name) {
+		(*error)->unknown_opt_name = ARGPAR_CALLOC(char,
+			strlen(unknown_opt_name) + 1 + (is_short ? 1 : 2));
+		if (!(*error)->unknown_opt_name) {
+			goto error;
+		}
+
+		if (is_short) {
+			strcpy((*error)->unknown_opt_name, "-");
+		} else {
+			strcpy((*error)->unknown_opt_name, "--");
+		}
+
+		strcat((*error)->unknown_opt_name, unknown_opt_name);
+	}
+
+	(*error)->opt_descr = opt_descr;
+	(*error)->is_short = is_short;
+	goto end;
+
+error:
+	argpar_error_destroy(*error);
+	ret = -1;
+
+end:
+	return ret;
+}
+
+ARGPAR_HIDDEN
+enum argpar_error_type argpar_error_type(
+		const struct argpar_error * const error)
+{
+	ARGPAR_ASSERT(error);
+	return error->type;
+}
+
+ARGPAR_HIDDEN
+unsigned int argpar_error_orig_index(const struct argpar_error * const error)
+{
+	ARGPAR_ASSERT(error);
+	return error->orig_index;
+}
+
+ARGPAR_HIDDEN
+const char *argpar_error_unknown_opt_name(
+		const struct argpar_error * const error)
+{
+	ARGPAR_ASSERT(error);
+	ARGPAR_ASSERT(error->type == ARGPAR_ERROR_TYPE_UNKNOWN_OPT);
+	ARGPAR_ASSERT(error->unknown_opt_name);
+	return error->unknown_opt_name;
+}
+
+ARGPAR_HIDDEN
+const struct argpar_opt_descr *argpar_error_opt_descr(
+		const struct argpar_error * const error, bool * const is_short)
+{
+	ARGPAR_ASSERT(error);
+	ARGPAR_ASSERT(error->type == ARGPAR_ERROR_TYPE_MISSING_OPT_ARG ||
+		error->type == ARGPAR_ERROR_TYPE_UNEXPECTED_OPT_ARG);
+	ARGPAR_ASSERT(error->opt_descr);
+
+	if (is_short) {
+		*is_short = error->is_short;
+	}
+
+	return error->opt_descr;
+}
+
+ARGPAR_HIDDEN
+void argpar_error_destroy(const struct argpar_error * const error)
+{
+	if (error) {
+		free(error->unknown_opt_name);
+		free((void *) error);
+	}
+}
+
+/*
+ * Finds and returns the _first_ descriptor having the short option name
+ * `short_name` or the long option name `long_name` within the option
+ * descriptors `descrs`.
+ *
+ * `short_name` may be `'\0'` to not consider it.
+ *
+ * `long_name` may be `NULL` to not consider it.
+ *
+ * Returns `NULL` if no descriptor is found.
+ */
 static
 const struct argpar_opt_descr *find_descr(
 		const struct argpar_opt_descr * const descrs,
@@ -291,106 +406,136 @@ end:
 	return !descr->short_name && !descr->long_name ? NULL : descr;
 }
 
+/* Return type of parse_short_opt_group() and parse_long_opt() */
 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_MEMORY = -2,
 };
 
+/*
+ * Parses the short option group argument `short_opt_group`, starting
+ * where needed depending on the state of `iter`.
+ *
+ * On success, sets `*item`.
+ *
+ * On error (except for `PARSE_ORIG_ARG_OPT_RET_ERROR_MEMORY`), sets
+ * `*error`.
+ */
 static
-enum parse_orig_arg_opt_ret parse_short_opts(const char * const short_opts,
+enum parse_orig_arg_opt_ret parse_short_opt_group(
+		const char * const short_opt_group,
 		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,
+		struct argpar_error ** 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");
-		goto error;
+	ARGPAR_ASSERT(strlen(short_opt_group) != 0);
+
+	if (!iter->short_opt_group_ch) {
+		iter->short_opt_group_ch = short_opt_group;
 	}
 
-	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;
-		}
+	/* Find corresponding option descriptor */
+	descr = find_descr(descrs, *iter->short_opt_group_ch, NULL);
+	if (!descr) {
+		const char unknown_opt_name[] =
+			{*iter->short_opt_group_ch, '\0'};
 
-		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;
-			}
+		ret = PARSE_ORIG_ARG_OPT_RET_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 (set_error(error, ARGPAR_ERROR_TYPE_UNKNOWN_OPT,
+				unknown_opt_name, NULL, true)) {
+			ret = PARSE_ORIG_ARG_OPT_RET_ERROR_MEMORY;
 		}
 
-		/* Create and append option argument */
-		opt_item = create_opt_item(descr, opt_arg);
-		if (!opt_item) {
-			goto error;
+		goto error;
+	}
+
+	if (descr->with_arg) {
+		if (iter->short_opt_group_ch[1]) {
+			/* `-oarg` form */
+			opt_arg = &iter->short_opt_group_ch[1];
+		} else {
+			/* `-o arg` form */
+			opt_arg = next_orig_arg;
+			used_next_orig_arg = true;
 		}
 
-		if (!push_item(parse_ret->items, &opt_item->base)) {
+		/*
+		 * We accept `-o ''` (empty option argument), but not
+		 * `-o` alone if an option argument is expected.
+		 */
+		if (!opt_arg || (iter->short_opt_group_ch[1] &&
+				strlen(opt_arg) == 0)) {
+			ret = PARSE_ORIG_ARG_OPT_RET_ERROR;
+
+			if (set_error(error, ARGPAR_ERROR_TYPE_MISSING_OPT_ARG,
+					NULL, descr, true)) {
+				ret = PARSE_ORIG_ARG_OPT_RET_ERROR_MEMORY;
+			}
+
 			goto error;
 		}
+	}
 
-		if (descr->with_arg) {
-			/* Option has an argument: no more options */
-			break;
-		}
+	/* 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;
+	}
+
+	*item = &opt_item->base;
+	iter->short_opt_group_ch++;
+
+	if (descr->with_arg || !*iter->short_opt_group_ch) {
+		/* Option has an argument: no more options */
+		iter->short_opt_group_ch = NULL;
 
-		/* Go to next short option */
-		short_opt_ch++;
+		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;
 }
 
+/*
+ * Parses the long option argument `long_opt_arg`.
+ *
+ * On success, sets `*item`.
+ *
+ * On error (except for `PARSE_ORIG_ARG_OPT_RET_ERROR_MEMORY`), sets
+ * `*error`.
+ */
 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,
+		struct argpar_error ** 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;
@@ -398,17 +543,10 @@ enum parse_orig_arg_opt_ret parse_long_opt(const char * const long_opt_arg,
 	/* Position of first `=`, if any */
 	const char *eq_pos;
 
-	/* Buffer holding option name when `long_opt_arg` contains `=` */
-	char buf[max_len + 1];
-
 	/* Option name */
 	const char *long_opt_name = long_opt_arg;
 
-	if (strlen(long_opt_arg) == 0) {
-		argpar_string_append_printf(&parse_ret->error,
-			"Invalid argument");
-		goto error;
-	}
+	ARGPAR_ASSERT(strlen(long_opt_arg) != 0);
 
 	/* Find the first `=` in original argument */
 	eq_pos = strchr(long_opt_arg, '=');
@@ -416,23 +554,31 @@ enum parse_orig_arg_opt_ret parse_long_opt(const char * const long_opt_arg,
 		const size_t long_opt_name_size = eq_pos - long_opt_arg;
 
 		/* Isolate the option name */
-		if (long_opt_name_size > max_len) {
-			argpar_string_append_printf(&parse_ret->error,
-				"Invalid argument `--%s`", long_opt_arg);
-			goto error;
+		while (long_opt_name_size > iter->tmp_buf.size - 1) {
+			iter->tmp_buf.size *= 2;
+			iter->tmp_buf.data = ARGPAR_REALLOC(iter->tmp_buf.data,
+				char, iter->tmp_buf.size);
+			if (!iter->tmp_buf.data) {
+				ret = PARSE_ORIG_ARG_OPT_RET_ERROR_MEMORY;
+				goto error;
+			}
 		}
 
-		memcpy(buf, long_opt_arg, long_opt_name_size);
-		buf[long_opt_name_size] = '\0';
-		long_opt_name = buf;
+		memcpy(iter->tmp_buf.data, long_opt_arg, long_opt_name_size);
+		iter->tmp_buf.data[long_opt_name_size] = '\0';
+		long_opt_name = iter->tmp_buf.data;
 	}
 
 	/* 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);
-		ret = PARSE_ORIG_ARG_OPT_RET_ERROR_UNKNOWN_OPT;
+		ret = PARSE_ORIG_ARG_OPT_RET_ERROR;
+
+		if (set_error(error, ARGPAR_ERROR_TYPE_UNKNOWN_OPT,
+				long_opt_name, NULL, false)) {
+			ret = PARSE_ORIG_ARG_OPT_RET_ERROR_MEMORY;
+		}
+
 		goto error;
 	}
 
@@ -444,15 +590,32 @@ 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,
-					"Missing required argument for option `--%s`",
-					long_opt_name);
+				ret = PARSE_ORIG_ARG_OPT_RET_ERROR;
+
+				if (set_error(error, ARGPAR_ERROR_TYPE_MISSING_OPT_ARG,
+						NULL, descr, false)) {
+					ret = PARSE_ORIG_ARG_OPT_RET_ERROR_MEMORY;
+				}
+
 				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.
+		 */
+		ret = PARSE_ORIG_ARG_OPT_RET_ERROR;
+
+		if (set_error(error, ARGPAR_ERROR_TYPE_UNEXPECTED_OPT_ARG,
+				NULL, descr, false)) {
+			ret = PARSE_ORIG_ARG_OPT_RET_ERROR_MEMORY;
+		}
+
+		goto error;
 	}
 
 	/* Create and append option argument */
@@ -461,27 +624,37 @@ 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;
 }
 
+/*
+ * Parses the original argument `orig_arg`.
+ *
+ * On success, sets `*item`.
+ *
+ * On error (except for `PARSE_ORIG_ARG_OPT_RET_ERROR_MEMORY`), sets
+ * `*error`.
+ */
 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,
+		struct argpar_error ** const error,
+		struct argpar_item ** const item)
 {
 	enum parse_orig_arg_opt_ret ret = PARSE_ORIG_ARG_OPT_RET_OK;
 
@@ -490,142 +663,127 @@ 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);
+		ret = parse_short_opt_group(&orig_arg[1],
+			next_orig_arg, descrs, iter, error, item);
 	}
 
 	return ret;
 }
 
-static
-bool prepend_while_parsing_arg_to_error(char **error,
-		const unsigned int i, const char * const arg)
+ARGPAR_HIDDEN
+struct argpar_iter *argpar_iter_create(const unsigned int argc,
+		const char * const * const argv,
+		const struct argpar_opt_descr * const descrs)
 {
-	char *new_error;
-	bool success;
+	struct argpar_iter *iter = ARGPAR_ZALLOC(struct argpar_iter);
 
-	ARGPAR_ASSERT(error);
-	ARGPAR_ASSERT(*error);
-
-	new_error = argpar_asprintf("While parsing argument #%u (`%s`): %s",
-		i + 1, arg, *error);
-	if (!new_error) {
-		success = false;
+	if (!iter) {
 		goto end;
 	}
 
-	free(*error);
-	*error = new_error;
-	success = true;
+	iter->user.argc = argc;
+	iter->user.argv = argv;
+	iter->user.descrs = descrs;
+	iter->tmp_buf.size = 128;
+	iter->tmp_buf.data = ARGPAR_CALLOC(char, iter->tmp_buf.size);
+	if (!iter->tmp_buf.data) {
+		argpar_iter_destroy(iter);
+		iter = NULL;
+		goto end;
+	}
 
 end:
-	return success;
+	return iter;
 }
 
 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)
+void argpar_iter_destroy(struct argpar_iter * const iter)
 {
-	struct argpar_parse_ret parse_ret = { 0 };
-	unsigned int i;
-	unsigned int non_opt_index = 0;
-
-	parse_ret.items = new_item_array();
-	if (!parse_ret.items) {
-		goto error;
+	if (iter) {
+		free(iter->tmp_buf.data);
+		free(iter);
 	}
+}
 
-	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;
-
-		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);
+ARGPAR_HIDDEN
+enum argpar_iter_next_status argpar_iter_next(
+		struct argpar_iter * const iter,
+		const struct argpar_item ** const item,
+		const struct argpar_error ** 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;
+	struct argpar_error ** const nc_error = (struct argpar_error **) error;
 
-			if (!non_opt_item) {
-				goto error;
-			}
+	ARGPAR_ASSERT(iter->i <= iter->user.argc);
 
-			non_opt_index++;
+	if (error) {
+		*nc_error = NULL;
+	}
 
-			if (!push_item(parse_ret.items, &non_opt_item->base)) {
-				goto error;
-			}
+	if (iter->i == iter->user.argc) {
+		status = ARGPAR_ITER_NEXT_STATUS_END;
+		goto end;
+	}
 
-			continue;
-		}
+	orig_arg = iter->user.argv[iter->i];
+	next_orig_arg =
+		iter->i < (iter->user.argc - 1) ?
+			iter->user.argv[iter->i + 1] : NULL;
 
-		/* Option argument */
-		parse_orig_arg_opt_ret = parse_orig_arg_opt(orig_arg,
-			next_orig_arg, descrs, &parse_ret, &used_next_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);
-
-			if (fail_on_unknown_opt) {
-				prepend_while_parsing_arg_to_error(
-					&parse_ret.error, i, orig_arg);
-				goto error;
-			}
+	if (strcmp(orig_arg, "-") == 0 || strcmp(orig_arg, "--") == 0 ||
+			orig_arg[0] != '-') {
+		/* Non-option argument */
+		const struct argpar_item_non_opt * const non_opt_item =
+			create_non_opt_item(orig_arg, iter->i,
+				iter->non_opt_index);
 
-			/*
-			 * 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;
+		if (!non_opt_item) {
+			status = ARGPAR_ITER_NEXT_STATUS_ERROR_MEMORY;
 			goto end;
-		case PARSE_ORIG_ARG_OPT_RET_ERROR:
-			prepend_while_parsing_arg_to_error(
-				&parse_ret.error, i, orig_arg);
-			goto error;
-		default:
-			abort();
 		}
 
-		if (used_next_orig_arg) {
-			i++;
-		}
+		iter->non_opt_index++;
+		iter->i++;
+		*item = &non_opt_item->base;
+		status = ARGPAR_ITER_NEXT_STATUS_OK;
+		goto end;
 	}
 
-	parse_ret.ingested_orig_args = argc;
-	free(parse_ret.error);
-	parse_ret.error = NULL;
-	goto end;
-
-error:
-	/* That's how we indicate that an error occured */
-	destroy_item_array(parse_ret.items);
-	parse_ret.items = NULL;
+	/* Option argument */
+	parse_orig_arg_opt_ret = parse_orig_arg_opt(orig_arg,
+		next_orig_arg, iter->user.descrs, iter, nc_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:
+		if (error) {
+			ARGPAR_ASSERT(*error);
+			(*nc_error)->orig_index = iter->i;
+		}
+		status = ARGPAR_ITER_NEXT_STATUS_ERROR;
+		break;
+	case PARSE_ORIG_ARG_OPT_RET_ERROR_MEMORY:
+		status = ARGPAR_ITER_NEXT_STATUS_ERROR_MEMORY;
+		break;
+	default:
+		abort();
+	}
 
 end:
-	return parse_ret;
+	return status;
 }
 
 ARGPAR_HIDDEN
-void argpar_parse_ret_fini(struct argpar_parse_ret *ret)
+unsigned int argpar_iter_ingested_orig_args(
+		const struct argpar_iter * const iter)
 {
-	ARGPAR_ASSERT(ret);
-
-	destroy_item_array(ret->items);
-	ret->items = NULL;
-
-	free(ret->error);
-	ret->error = NULL;
+	return iter->i;
 }