[Bug] Incorrect JSON serialization tag

[Vasco-jofra]

Hi! While doing a quick code search, I found that the code incorrectly exposes the MaxTokens field with the - key during JSON marshaling and unmarshaling. This is caused by the json:"-,omitempty" tag; by adding the , after the -, the - becomes the field key.

langchaingo/llms/openai/internal/openaiclient/chat.go

Line 37 in d3e43b6

MaxTokens int `json:"-,omitempty"`

langchaingo/llms/openai/internal/openaiclient/completions.go

Line 13 in d3e43b6

MaxTokens int `json:"-,omitempty"`

You can confirm this Go behavior with the following script:

package main

import (
	"encoding/json"
	"fmt"
)


func main() {
	type Test struct {
		MaxTokens string `json:"-,omitempty"`
	}
	u := Test{}
	_ = json.Unmarshal([]byte(`{"-": "asd"}`), &u)
	fmt.Printf("Result: %#v\n", u)
	// Result: main.Test{MaxTokens:"asd"}
}