Create UPGRADE.md

Author: antonmedv

UPGRADE.md

@@ -0,0 +1,29 @@
+# Upgrade
+
+This file contains information on how to upgrade between major versions.
+
+## 0.x → 1.x
+
+### Deprecated `expr.Names` and `expr.Funcs`
+
+Use `expr.Define` or `expr.With` instead of.
+
+In new version you can specify types of variables, if you don't need type info use `interface{}`:
+
+```go
+expr.Parse(code, expr.Names('Foo', 'Bar'))
+
+// Change to
+
+var foo, bar interface{}
+expr.Parse(code, expr.Define('Foo', foo), expr.Define('Bar', bar))
+
+// Or
+
+type params struct {
+    Foo interface{}
+    Bar interface{}
+}
+expr.Parse(code, expr.With(params{}))
+```
+