From 1161a6e822d2461aff7240503437078a841f62f6 Mon Sep 17 00:00:00 2001
From: "Ben L. Titzer" <ben.titzer@gmail.com>
Date: Thu, 27 Jun 2024 15:46:34 -0400
Subject: [PATCH] [ideas] Ideas for matching ranges

---
 doc/ideas/MatchRange.v3 | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 doc/ideas/MatchRange.v3

diff --git a/doc/ideas/MatchRange.v3 b/doc/ideas/MatchRange.v3
new file mode 100644
index 000000000..6934b367f
--- /dev/null
+++ b/doc/ideas/MatchRange.v3
@@ -0,0 +1,36 @@
+//Idea: allow matching within a range and the rest of a range
+
+type T {
+	case A(f: int);
+	case B(g: int);
+}
+
+def m(t: Range<T>) -> (int, Range<T>) {
+	match (t) {
+		A(f) ... rest => return (f + 77, rest); // "rest" has type Range<T>
+		B(g) ... rest => return (g + 99, rest); // "rest" has type Range<T>
+	}
+}
+
+def keywords(str: Range<byte>) -> (int, Range<T>) {
+	match(str) {
+		"if" ... rest => return (11, rest);
+		"case" ... rest => return (12, rest);
+		"match" ... rest => return (13, rest);
+	}
+	return (-1, str);
+}
+
+def parse_literal(str: Range<byte>) -> (Lit, Range<T>) {
+	match (str) {
+		IntLiteralMatch(x) ... rest => (Lit.Int(x), rest);
+		BoolLiteralMatch(x) ... rest => (Lit.Bool(x), rest);
+		"case ${x: int} of foo" ... rest => (Lit.CaseInt(x), rest);
+	}
+}
+
+def match(str: Range<byte>) -> IntLiteralMatch(x: int) {
+	for (i < str.length) ...
+	return false;
+	return (true, length, val)
+}