1 files changed, 14 insertions, 0 deletions
diff --git a/const.go b/const.go
new file mode 100644
index 0000000..60bae20
--- /dev/null
+++ b/const.go
@@ -0,0 +1,14 @@
+package main
+
+import "math"
+
+// parseConstant returns nil if s is not a valid constant.
+func parseConstant(s string) *float64 {
+	switch s {
+	case "pi":
+		// Assign to variable because can't take address of constant.
+		var pi float64 = math.Pi
+		return &pi
+	}
+	return nil
+}