core: vm: sqlvm: remove optional interface and add print tag for detail

There are some changes in print ast utility.
1. instead of using optional interface to get detail, use reflect
2. implement a `print` field tag for printer switching detail mode or
not

3 files changed, 49 insertions, 99 deletions

diff --git a/core/vm/sqlvm/ast/ast.go b/core/vm/sqlvm/ast/ast.go
index 61a990e20..654e778e4 100644
--- a/core/vm/sqlvm/ast/ast.go
+++ b/core/vm/sqlvm/ast/ast.go
@@ -239,29 +239,11 @@ type FunctionOperatorNode struct{ BinaryOperatorNode }
 // Options
 // ---------------------------------------------------------------------------
 
-// Optional defines the interface for printing AST.
-type Optional interface {
-	GetOption() map[string]interface{}
-}
-
-// NilOptionNode is a base struct implementing Optional interface.
-type NilOptionNode struct{}
-
-// GetOption returns a value for printing AST.
-func (n NilOptionNode) GetOption() map[string]interface{} { return nil }
-
 // WhereOptionNode is 'WHERE' used in SELECT, UPDATE, DELETE.
 type WhereOptionNode struct {
 	Condition interface{}
 }
 
-// GetOption returns a value for printing AST.
-func (n WhereOptionNode) GetOption() map[string]interface{} {
-	return map[string]interface{}{
-		"Condition": n.Condition,
-	}
-}
-
 // OrderOptionNode is an expression in 'ORDER BY' used in SELECT.
 type OrderOptionNode struct {
 	Expr       interface{}
@@ -269,106 +251,53 @@ type OrderOptionNode struct {
 	NullsFirst bool
 }
 
-// GetOption returns a value for printing AST.
-func (n OrderOptionNode) GetOption() map[string]interface{} {
-	return map[string]interface{}{
-		"Expr":       n.Expr,
-		"Desc":       n.Desc,
-		"NullsFirst": n.NullsFirst,
-	}
-}
-
 // GroupOptionNode is 'GROUP BY' used in SELECT.
 type GroupOptionNode struct {
 	Expr interface{}
 }
 
-// GetOption returns a value for printing AST.
-func (n GroupOptionNode) GetOption() map[string]interface{} {
-	return map[string]interface{}{
-		"Expr": n.Expr,
-	}
-}
-
 // OffsetOptionNode is 'OFFSET' used in SELECT.
 type OffsetOptionNode struct {
 	Value IntegerValueNode
 }
 
-// GetOption returns a value for printing AST.
-func (n OffsetOptionNode) GetOption() map[string]interface{} {
-	return map[string]interface{}{
-		"Value": n.Value,
-	}
-}
-
 // LimitOptionNode is 'LIMIT' used in SELECT.
 type LimitOptionNode struct {
 	Value IntegerValueNode
 }
 
-// GetOption returns a value for printing AST.
-func (n LimitOptionNode) GetOption() map[string]interface{} {
-	return map[string]interface{}{
-		"Value": n.Value,
-	}
-}
-
 // InsertWithColumnOptionNode stores columns and values used in INSERT.
 type InsertWithColumnOptionNode struct {
 	Column []interface{}
 	Value  []interface{}
 }
 
-// GetOption returns a value for printing AST.
-func (n InsertWithColumnOptionNode) GetOption() map[string]interface{} {
-	return map[string]interface{}{
-		"Column": n.Column,
-		"Value":  n.Value,
-	}
-}
-
 // InsertWithDefaultOptionNode is 'DEFAULT VALUES' used in INSERT.
-type InsertWithDefaultOptionNode struct{ NilOptionNode }
+type InsertWithDefaultOptionNode struct{}
 
 // PrimaryOptionNode is 'PRIMARY KEY' used in CREATE TABLE.
-type PrimaryOptionNode struct{ NilOptionNode }
+type PrimaryOptionNode struct{}
 
 // NotNullOptionNode is 'NOT NULL' used in CREATE TABLE.
-type NotNullOptionNode struct{ NilOptionNode }
+type NotNullOptionNode struct{}
 
 // UniqueOptionNode is 'UNIQUE' used in CREATE TABLE and CREATE INDEX.
-type UniqueOptionNode struct{ NilOptionNode }
+type UniqueOptionNode struct{}
 
 // AutoIncrementOptionNode is 'AUTOINCREMENT' used in CREATE TABLE.
-type AutoIncrementOptionNode struct{ NilOptionNode }
+type AutoIncrementOptionNode struct{}
 
 // DefaultOptionNode is 'DEFAULT' used in CREATE TABLE.
 type DefaultOptionNode struct {
 	Value interface{}
 }
 
-// GetOption returns a value for printing AST.
-func (n DefaultOptionNode) GetOption() map[string]interface{} {
-	return map[string]interface{}{
-		"Value": n.Value,
-	}
-}
-
 // ForeignOptionNode is 'REFERENCES' used in CREATE TABLE.
 type ForeignOptionNode struct {
 	Table  IdentifierNode
 	Column IdentifierNode
 }
 
-// GetOption returns a value for printing AST.
-func (n ForeignOptionNode) GetOption() map[string]interface{} {
-	return map[string]interface{}{
-		"Table":  n.Table,
-		"Column": n.Column,
-	}
-}
-
 // ---------------------------------------------------------------------------
 // Statements
 // ---------------------------------------------------------------------------
diff --git a/core/vm/sqlvm/ast/printer.go b/core/vm/sqlvm/ast/printer.go
index 25f04e863..e8c612637 100644
--- a/core/vm/sqlvm/ast/printer.go
+++ b/core/vm/sqlvm/ast/printer.go
@@ -3,10 +3,11 @@ package ast
 import (
 	"fmt"
 	"reflect"
+	"unicode/utf8"
 )
 
 // PrintAST prints ast to stdout.
-func PrintAST(n interface{}, indent string) {
+func PrintAST(n interface{}, indent string, detail bool) {
 	if n == nil {
 		fmt.Printf("%snil\n", indent)
 		return
@@ -25,38 +26,28 @@ func PrintAST(n interface{}, indent string) {
 	}
 	name = name + typeOf.Name()
 
-	if op, ok := n.(Optional); ok {
-		fmt.Printf("%s%s", indent, name)
-		m := op.GetOption()
-		if m == nil {
-			fmt.Printf("\n")
-			return
-		}
-		fmt.Printf(":\n")
-		for k := range m {
-			fmt.Printf("%s  %s:\n", indent, k)
-			PrintAST(m[k], indent+"    ")
-		}
-		return
-	}
 	if op, ok := n.(UnaryOperator); ok {
 		fmt.Printf("%s%s:\n", indent, name)
 		fmt.Printf("%s  Target:\n", indent)
-		PrintAST(op.GetTarget(), indent+"    ")
+		PrintAST(op.GetTarget(), indent+"    ", detail)
 		return
 	}
 	if op, ok := n.(BinaryOperator); ok {
 		fmt.Printf("%s%s:\n", indent, name)
 		fmt.Printf("%s  Object:\n", indent)
-		PrintAST(op.GetObject(), indent+"    ")
+		PrintAST(op.GetObject(), indent+"    ", detail)
 		fmt.Printf("%s  Subject:\n", indent)
-		PrintAST(op.GetSubject(), indent+"    ")
+		PrintAST(op.GetSubject(), indent+"    ", detail)
 		return
 	}
 	if arr, ok := n.([]interface{}); ok {
+		if len(arr) == 0 {
+			fmt.Printf("%s[]\n", indent)
+			return
+		}
 		fmt.Printf("%s[\n", indent)
 		for idx := range arr {
-			PrintAST(arr[idx], indent+"  ")
+			PrintAST(arr[idx], indent+"  ", detail)
 		}
 		fmt.Printf("%s]\n", indent)
 		return
@@ -65,5 +56,29 @@ func PrintAST(n interface{}, indent string) {
 		fmt.Printf("%s%s: %s\n", indent, name, stringer.String())
 		return
 	}
-	fmt.Printf("%s%s: %+v\n", indent, name, valueOf.Interface())
+	if typeOf.Kind() == reflect.Struct {
+		fmt.Printf("%s%s", indent, name)
+		l := typeOf.NumField()
+		if l == 0 {
+			fmt.Printf(" {}\n")
+			return
+		}
+		fmt.Printf(" {\n")
+		for i := 0; i < l; i++ {
+			if !detail && typeOf.Field(i).Tag.Get("print") == "-" {
+				continue
+			}
+			fmt.Printf("%s  %s:\n", indent, typeOf.Field(i).Name)
+			PrintAST(valueOf.Field(i).Interface(), indent+"    ", detail)
+		}
+		fmt.Printf("%s}\n", indent)
+		return
+	}
+	if bs, ok := n.([]byte); ok {
+		if utf8.Valid(bs) {
+			fmt.Printf("%s%s\n", indent, bs)
+			return
+		}
+	}
+	fmt.Printf("%s%+v\n", indent, valueOf.Interface())
 }
diff --git a/core/vm/sqlvm/cmd/ast-printer/main.go b/core/vm/sqlvm/cmd/ast-printer/main.go
index 4911273c5..200f47173 100644
--- a/core/vm/sqlvm/cmd/ast-printer/main.go
+++ b/core/vm/sqlvm/cmd/ast-printer/main.go
@@ -1,17 +1,23 @@
 package main
 
 import (
+	"flag"
 	"fmt"
-	"os"
 
 	"github.com/dexon-foundation/dexon/core/vm/sqlvm/ast"
 	"github.com/dexon-foundation/dexon/core/vm/sqlvm/parser"
 )
 
 func main() {
-	n, err := parser.ParseString(os.Args[1])
+	var detail bool
+	flag.BoolVar(&detail, "detail", false, "print struct detail")
+
+	flag.Parse()
+
+	n, err := parser.ParseString(flag.Arg(0))
+	fmt.Printf("detail: %t\n", detail)
 	fmt.Printf("err: %+v\n", err)
 	if err == nil {
-		ast.PrintAST(n, "")
+		ast.PrintAST(n, "", detail)
 	}
 }