1 files changed, 20 insertions, 0 deletions
diff --git a/src/cmd/yacc/testdata/expr/README b/src/cmd/yacc/testdata/expr/README
new file mode 100644
index 000000000..302ef57a7
--- /dev/null
+++ b/src/cmd/yacc/testdata/expr/README
@@ -0,0 +1,20 @@
+This directory contains a simple program demonstrating how to use
+the Go version of yacc.
+
+To build it:
+
+	$ go generate
+	$ go build
+
+or
+
+	$ go generate
+	$ go run expr.go
+
+The file main.go contains the "go generate" command to run yacc to
+create expr.go from expr.y. It also has the package doc comment,
+as godoc will not scan the .y file.
+
+The actual implementation is in expr.y.
+
+The program is not installed in the binary distributions of Go.