hare

commit 3363b79377b5361aead757769f12d394b94b3ee7
parent a3faae6f4b50c5b456a0be5ecc939f87f588ec95
Author: Drew DeVault <sir@cmpwn.com>
Date:   Mon,  1 Feb 2021 12:30:23 -0500

fmt: new module (WIP)

Diffstat:
A
fmt/fmt.ha
 | 
22
++++++++++++++++++++++

1 file changed, 22 insertions(+), 0 deletions(-)
diff --git a/fmt/fmt.ha b/fmt/fmt.ha
@@ -0,0 +1,22 @@
+// A format string consists of a string of literal characters, to be printed
+// verbatim, and format sequences, which describe how to format arguments from
+// a set of variadic parameters for printing.
+//
+// A format sequence is enclosed in curly braces '{}'. An empty sequence takes
+// the next argument from the parameter list, in order. A specific parameter can
+// be used by numbering it from zero: '{0}', '{1}', and so on. A colon may be
+// used to specify additional constraints on the format in a type-specific
+// manner: '{0:x} will print a number in hexadecimal.
+//
+// TODO: Document this more I guess
+use io;
+use types;
+
+// Tagged union of all types which are formattable.
+export type formattable = (...types::numeric | uintptr | str | *void);
+
+// Formats text for printing and writes it to an [io::stream].
+export fn fprintf(s: *io::stream, fmt: str,
+		args: formattable...) (io::error | size) = {
+	return io::unsupported: io::error; // TODO: Blocked on rune picking
+};