Start of variadic printf post

projects/Idris/Idris.ipkg

@@ -18,6 +18,7 @@ authors = "Nathan McCarty"
 -- modules to install
 modules = Idris
         , Posts.HelloWorld
+        , LessMacrosMoreTypes.Printf
 
 -- main file (i.e. file to load at REPL)
 -- main =

projects/Idris/src/LessMacrosMoreTypes/Printf.md

@@ -0,0 +1,45 @@
+# Type Safe Variadic printf
+
+```idris hide
+module LessMacrosMoreTypes.Printf
+
+%default total
+```
+
+While C can provide convenient string formatting by having hideously memory
+unsafe variadics, and dynamic languages, like python, can do the same while
+being memory safe by not being type safe, many type safe languages, such as
+Rust, are forced to provide such functionality through the use of a macro.
+Dependently typed languages, like Idris, can provide a printf like formatting
+interface, while maintaining both memory and type saftey, without the need for
+the macro. We will explore this by implementing a simplified version of `printf`
+in Idris from scratch.
+
+This article is inspired by an exercise from chapter 6 of [Type Driven
+Development with
+Idris](https://www.manning.com/books/type-driven-development-with-idris), and is
+written as a literate Idris file.
+
+## Gameplan
+
+Our goal is to provide a printf function that can be called, much like it's C equivlant, like so:
+
+> [!NOTE]
+> As this is a literate Idris document, and we haven't defined our `printf`
+> function yet, we have to use a `failing` block to ask the compiler to check
+> that this code parses, and syntax highlight it for us, but not attempt to
+> actually compile it.
+
+```idris
+failing
+  example_usage : String
+  example_usage = printf "%s %d %02d" "hello" 1 2
+```
+
+
+
+## Parsing a Format String
+
+## Calculating a Type From a Format String
+
+## printf