From fce9b28f6d0eae01719977962f9aff14f39a9d1a Mon Sep 17 00:00:00 2001
From: Charles Iliya Krempeaux <iamreiver@gmail.com>
Date: Wed, 4 Oct 2023 17:36:57 +0900
Subject: [PATCH] initial commits

---
 digit.go      |  8 ++++++++
 digit_test.go | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+)
 create mode 100644 digit.go
 create mode 100644 digit_test.go

diff --git a/digit.go b/digit.go
new file mode 100644
index 0000000..0e510d6
--- /dev/null
+++ b/digit.go
@@ -0,0 +1,8 @@
+package rfc2234
+
+// IsDigit returns true if value of 'r' matches 'ALPHA' as defined in IETF RFC-2234:
+//
+//	DIGIT =  %30-%39   ; 0-9
+func IsDigit(r rune) bool {
+	return '0' <= r && r <= '9'
+}
diff --git a/digit_test.go b/digit_test.go
new file mode 100644
index 0000000..939eaba
--- /dev/null
+++ b/digit_test.go
@@ -0,0 +1,57 @@
+package rfc2234_test
+
+import (
+	"testing"
+
+	"sourcecode.social/reiver/go-rfc2234"
+)
+
+func TestIsDigit(t *testing.T) {
+
+	tests := []struct{
+		Rune rune
+		Expected bool
+	}{
+	}
+
+	for r:=rune(0); r < '0'; r++ {
+		tests = append(tests, struct{
+			Rune rune
+			Expected bool
+		}{
+			Rune: r,
+			Expected: false,
+		})
+	}
+	for r:='0'; r <= '9'; r++ {
+		tests = append(tests, struct{
+			Rune rune
+			Expected bool
+		}{
+			Rune: r,
+			Expected: true,
+		})
+	}
+	for r:='9'+1; r <= rune(127); r++ {
+		tests = append(tests, struct{
+			Rune rune
+			Expected bool
+		}{
+			Rune: r,
+			Expected: false,
+		})
+	}
+
+	for testNumber, test := range tests {
+		actual := rfc2234.IsDigit(test.Rune)
+		expected := test.Expected
+
+		if expected != actual {
+			t.Errorf("For test #%d, the actual value for rfc2234.IsDigit() is not what was expected.", testNumber)
+			t.Logf("EXPECTED: %t", expected)
+			t.Logf("ACTUAL:   %t", actual)
+			t.Logf("RUNE: (%U) %q", test.Rune, string(test.Rune))
+			continue
+		}
+	}
+}