goreq | simple Go HTTP request client library | REST library

Since the Timeout method sets the dealines for dial, read, and write, you can use os.IsTimeout (all error types in the net and net/url packages implement Timeout() bool). Contexts are not supported by gorequest, so context.Canceled doesn't have to be considered:

You can use fileObj.WriteAt(content, offSet) to append content to the file.

By calling res.Body.ToString() you read the whole body of the response. Next, when you call res.Body.FromJsonTo(), body is empty and therefore EOF error is returned. Removing ToString() from your code should help.

TL;DR

Can I write it in one struct

Yes

or do I need to use maps for the bid and ask arrays, and yet another struct for the bid and ask objects?

Yes

Before I actually do the hand holding here, I'm gonna recommend that you actually spend some more time getting used to the way things are done in Go. This might be tedious work but it is very simple.

Long Version

I'm not sure how I would create a struct which represents this complex structure.

You are going to do it the same way if you just had to represent this in your program, without any JSON.

Let's explain what you have in that message in English before we translate it to Go:

You have a struct with the fields:

• Success - Boolean
• Message - String
• Result - Struct

Now, Result is also a struct, so we need to describe it:

• Bids - Array of Struct
• Asks - Array of Struct
• Slip - Integer

Let's do the same for Bids and Asks (the look the same so I'll save space)

• Quantity - Integer
• Price - Float64
• Cm - String

Now let's define our struct:

Let's call the container struct "Response" and the result one "Result"

You're sending a json body with your Go code, but an application/x-www-form-urlencoded body with curl.

You can encode the string manually as you've done with curl: