accounts/abi: added output parsing & added call mechanism

Added calling mechanism and return value parsing

accounts/abi/argument.go

@@ -0,0 +1,48 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+// Argument holds the name of the argument and the corresponding type.
+// Types are used when packing and testing arguments.
+type Argument struct {
+	Name string
+	Type Type
+}
+
+func (a *Argument) UnmarshalJSON(data []byte) error {
+	var extarg struct {
+		Name string
+		Type string
+	}
+	err := json.Unmarshal(data, &extarg)
+	if err != nil {
+		return fmt.Errorf("argument json err: %v", err)
+	}
+
+	a.Type, err = NewType(extarg.Type)
+	if err != nil {
+		return err
+	}
+	a.Name = extarg.Name
+
+	return nil
+}