You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: visitor.go
    path of file: ./repos/gotosocial/vendor/github.com/bytedance/sonic/ast
    
    the code of the file until where you have to start completion: /*
 * Copyright 2021 ByteDance Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package ast

import (
    `encoding/json`

    `github.com/bytedance/sonic/internal/native/types`
)

// Visitor handles the callbacks during preorder traversal of a JSON AST.
//
// According to the JSON RFC8259, a JSON AST can be defined by
// the following rules without seperator / whitespace tokens.
//
//  JSON-AST  = value
//  value     = false / null / true / object / array / number / string
//  object    = begin-object [ member *( member ) ] end-object
//  member    = string value
//  array     = begin-array [ value *( value ) ] end
    
func (self *traverser) decodeArray() error {
    sp := self.parser.p
    ns := len(self.parser.s)

    /* check for EOF */
    self.parser.p = self.parser.lspace(sp)
    if self.parser.p >= ns {
        return types.ERR_EOF
    }

    /* check for empty array */
    if self.parser.s[self.parser.p] == ']' {
        self.parser.p++
        if err := self.visitor.OnArrayBegin(0); err != nil {
            return err
        }
        return self.visitor.OnArrayEnd()
    }

    /* allocate array space and parse every element */
    if err := self.visitor.OnArrayBegin(_DEFAULT_NODE_CAP); err != nil {
        return err
    }
    for {
        /* decode the value */
        if err := self.decodeValue(); err != nil {
            return err
        }
        self.parser.p = self.parser.lspace(self.parser.p)

        /* check for EOF */
        if self.parser.p >= ns {
            return types.ERR_EOF
        }

        /* check for the next character */
        switch self.parser.s[self.parser.p] {
        case ',':
            self.parser.p++
        case ']':
            self.parser.p++
            return self.visitor.OnArrayEnd()
        default:
            return types.ERR_INVALID_CHAR
        }
    }
}