core: vm: sqlvm: add sql language parser prototyping

Add sql language parser prototyping along with

1. grammar file implemented with github.com/mna/pigeon
2. ast node struct definition
3. simple parser test which only test if error existed
4. ast printer utility for visualizing parsing result

1 files changed, 16 insertions, 0 deletions

diff --git a/core/vm/sqlvm/cmd/ast-printer/main.go b/core/vm/sqlvm/cmd/ast-printer/main.go
new file mode 100644
index 000000000..ad10a54ce
--- /dev/null
+++ b/core/vm/sqlvm/cmd/ast-printer/main.go
@@ -0,0 +1,16 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/dexon-foundation/dexon/core/vm/sqlvm"
+)
+
+func main() {
+	n, err := sqlvm.ParseString(os.Args[1])
+	fmt.Printf("err: %+v\n", err)
+	if err == nil {
+		sqlvm.PrintAST(n, "")
+	}
+}