From 03e8366b7e11e1b6c971f70d22fef07f7ad32448 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yaroslav=20de=20la=20Pe=C3=B1a=20Smirnov?=
 <yps@yaroslavps.com>
Date: Tue, 20 Feb 2024 23:49:31 +0300
Subject: optionals v0.2.0: custom-named optionals

Can now declare custom named optionals, in order to declare optionals
for two-token type names.
---
 optional/optional-test.c | 12 ++++++++++--
 optional/optional.h      | 45 ++++++++++++++++++++++++++++++++-------------
 2 files changed, 42 insertions(+), 15 deletions(-)

(limited to 'optional')

diff --git a/optional/optional-test.c b/optional/optional-test.c
index 88577d3..73597e5 100644
--- a/optional/optional-test.c
+++ b/optional/optional-test.c
@@ -2,9 +2,11 @@
 #include "../utest/utest.h"
 
 #include <stdio.h>
+#include <string.h>
 
-OPTIONALDEC(int);
-OPTIONALDEC(char);
+DECL_OPTIONAL(int);
+DECL_OPTIONAL(char);
+DECL_NAMED_OPTIONAL(str, char *);
 
 struct my_struct {
 	OPTIONAL(int) a;
@@ -27,6 +29,12 @@ TEST_BEGIN(test_optional_example)
 
 	OPTIONAL(char) y = OPTNONE;
 	OPTIONAL(char) z = OPTSOME('z');
+
+	OPTIONAL(str) s = OPTSOME("hello, world!");
+
+	expect(!strcmp(opt_default(s, "NULL!"), "hello, world!"),
+		   "expected to contain string \"hello, world!\"");
+
 	float xy, xz;
 
 	expect(opt_has(my.a), "expected to contain something");
diff --git a/optional/optional.h b/optional/optional.h
index 6dcc3e2..4eb0e87 100644
--- a/optional/optional.h
+++ b/optional/optional.h
@@ -1,8 +1,8 @@
 /* SPDX-License-Identifier: MIT */
 /**
- * optional.h - Macros for optional types. v0.1.0
+ * optional.h - Macros for optional types. v0.2.0
  *
- * Copyright (C) 2023 Yaroslav de la Peña Smirnov
+ * Copyright (C) 2023-2024 Yaroslav de la Peña Smirnov
  *
  * Documentation
  * =============
@@ -13,9 +13,6 @@
  * a certain type inside itself at any time. Before declaring a variable of a
  * certain OPTIONAL type, said OPTIONAL type should be declared with the
  * OPTIONALDEC macro.
- *
- * Currently only supports types that are composed of one token, i.e. no
- * structs, enums, unions, etc. Might expand it in the future to support them.
  */
 
 #ifndef OPTIONAL_H
@@ -24,10 +21,28 @@
 #include <stdbool.h>
 
 /**
- * OPTIONALDEC - declare OPTIONAL type that holds data of type @T
+ * DECLARE_NAMED_OPTIONAL - declare OPTIONAL that holds type @T called @optname
+ * @optname:	name of Optional type.
+ * @T:			type to hold.
+ *
+ * This macro is used to give a custom name to the optional type. This is,
+ * unfortunately, needed due to the nature of C's type system and the fact that
+ * we have types in C that are made up of several tokens, which does not bode
+ * well for these kinds of macros.
+ */
+#define DECL_NAMED_OPTIONAL(optname, T) \
+	struct __OPTIONAL_##optname {       \
+		T	 data;                      \
+		bool has;                       \
+	}
+
+/**
+ * DECLARE_OPTIONAL - declare OPTIONAL "type" that holds data of type @T
  * @T:		the type of data to hold.
+ *
+ * The type @T also becomes the "name" of the optional type.
  */
-#define OPTIONALDEC(T) struct __OPTIONAL_##T { bool has; T data; }
+#define DECL_OPTIONAL(T) DECL_NAMED_OPTIONAL(T, T)
 
 /**
  * OPTIONAL - declare an object that optionally holds type @T
@@ -38,13 +53,19 @@
 /**
  * OPTNONE - initialize an OPTIONAL object to hold nothing.
  */
-#define OPTNONE { .has = false }
+#define OPTNONE      \
+	{                \
+		.has = false \
+	}
 
 /**
  * OPTSOME - initialize an OPTIONAL object to hold something.
  * @d:	data to hold.
  */
-#define OPTSOME(d) { .has = true, .data = d }
+#define OPTSOME(d)             \
+	{                          \
+		.has = true, .data = d \
+	}
 
 /**
  * opt_set_none - set an OPTIONAL object to hold nothing.
@@ -57,8 +78,7 @@
  * @opt:	OPTIONAL object.
  * @d:		data to hold.
  */
-#define opt_set_some(opt, d) \
-	((opt).has = true, (opt).data = d)
+#define opt_set_some(opt, d) ((opt).has = true, (opt).data = d)
 
 /**
  * opt_has - true if an OPTIONAL object has something.
@@ -79,8 +99,7 @@
  *
  * Returns true if there was something, false if there wasn't.
  */
-#define opt_unwrap(src, dst) \
-	(opt_has(src) ? (dst = (src).data, true) : (false))
+#define opt_unwrap(src, dst) (opt_has(src) ? (dst = (src).data, true) : (false))
 
 /**
  * opt_default - get something from @src or default to @def.
-- 
cgit v1.2.3