Propose a new 5th page to introduce argument counting

book/pages/05_range.md

@@ -0,0 +1,58 @@
+# Optional arguments: General case
+
+:::{admonition} Work In Progress
+:class: warning
+This page is a draft
+:::
+
+OK so we now know how to have a few optional arguments with a default value, but what if we want to do something entierly different depending on the number of arguments provided ?
+
+## Objective
+
+A `range` macro similar to the python builtin function, that allows one to iterate over a range of integers:
+- `range(STOP)`{l=python} iterates from 0 to _STOP_, _STOP_ excluded
+- `range(START, STOP)`{l=python} iterates from _START_ to _STOP_, _STOP_ excluded
+- `range(START, STOP, STEP)`{l=python} iterates from _START_ to _STOP_ by steps of _STEP_, _STOP_ excluded
+
+Examples:
+- `range(5)`: `0 1 2 3 4`
+- `range(3, 8)`: `3 4 5 6 7`
+- `range(2, 7, 3)`: `2 5`
+
+How will it look like in C ? Well it's up to you, here are a few propositions:
+:::::{tab-set}
+::::{tab-item} Syntax 1
+```{code-block} C
+:caption: Indented correctly by you text editor by default
+for (int in_range(i, 5))
+	/* 0 1 2 3 4 */;
+for (int in_range(i, 3, 8))
+	/* 3 4 5 6 7 */;
+for (int in_range(i, 2, 7, 3))
+	/* 2 5 */;
+```
+::::
+::::{tab-item} Syntax 2
+```{code-block} C
+:caption: Single parenthesis level
+for_in_range(int, i, 5)
+	/* 0 1 2 3 4 */;
+for_in_range(int, i, 3, 8)
+	/* 3 4 5 6 7 */;
+for_in_range(int, i, 2, 7, 3)
+	/* 2 5 */;
+```
+::::
+::::{tab-item} Syntax 3
+```{code-block} C
+:caption: Explicit variable declaration
+int i;
+for_in_range(i, 5)
+	/* 0 1 2 3 4 */;
+for_in_range(i, 3, 8)
+	/* 3 4 5 6 7 */;
+for_in_range(i, 2, 7, 3)
+	/* 2 5 */;
+```
+::::
+:::::

book/pages/index.rst

@@ -15,5 +15,5 @@ Black Magic
    02_use
    03_log
    04_default
-   05_argcount
+   05_range
    quotes

book/samples/03_stringline3.c

@@ -11,10 +11,10 @@
 
 #define log_log(LEVEL, MESSAGE, ...)                                                         \
 	printf("|" LEVEL "|`" __FILE__ "`|`%s`|" STRINGIZE_EVALUATED(__LINE__) "|" MESSAGE "\n", \
-	       __func__ __VA_OPT__(, ) __VA_ARGS__)
+	       __func__ __VA_OPT__(,) __VA_ARGS__)
 
-#define log_debug(MESSAGE, ...) log_log("DEBUG", MESSAGE __VA_OPT__(, ) __VA_ARGS__)
-#define log_error(MESSAGE, ...) log_log("ERROR", MESSAGE __VA_OPT__(, ) __VA_ARGS__)
+#define log_debug(MESSAGE, ...) log_log("DEBUG", MESSAGE __VA_OPT__(,) __VA_ARGS__)
+#define log_error(MESSAGE, ...) log_log("ERROR", MESSAGE __VA_OPT__(,) __VA_ARGS__)
 
 void foobar(const char* file_name)
 {

book/samples/05_limitation.c

@@ -0,0 +1,22 @@
+#include <stdio.h>
+
+#define ARG_10(A, B, C, D, E, F, G, H, I, J, ...) J
+#define ARG_COUNT(...) ARG_10(__VA_ARGS__ __VA_OPT__(,) 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
+
+#define FOO(...) printf("FOO was called with %i arguments\n", ARG_COUNT(__VA_ARGS__))
+
+#define SPELL_0 "zero"
+#define SPELL_1 "one"
+#define SPELL_2 "two"
+#define SPELL_3 "three"
+#define SPELL_4 "four"
+
+#define SPELL(N) SPELL_ ## N
+
+int main()
+{
+	FOO();
+	FOO(1, 2, 3, 4, 5);
+
+	printf("%s %s\n", SPELL(4), SPELL(2));
+}