Golang bindings initial working version(#534)

* WIP

* Fix includes

* Try to fix linking issues

* Refinements

* allow to load MPT and llama models too

* cleanup, add example, add README

gpt4all-bindings/golang/example/main.go

@@ -0,0 +1,82 @@
+package main
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"runtime"
+	"strings"
+
+	gpt4all "github.com/nomic-ai/gpt4all/gpt4all-bindings/golang"
+)
+
+var (
+	threads = 4
+	tokens  = 128
+)
+
+func main() {
+	var model string
+
+	flags := flag.NewFlagSet(os.Args[0], flag.ExitOnError)
+	flags.StringVar(&model, "m", "./models/7B/ggml-model-q4_0.bin", "path to q4_0.bin model file to load")
+	flags.IntVar(&threads, "t", runtime.NumCPU(), "number of threads to use during computation")
+	flags.IntVar(&tokens, "n", 512, "number of tokens to predict")
+
+	err := flags.Parse(os.Args[1:])
+	if err != nil {
+		fmt.Printf("Parsing program arguments failed: %s", err)
+		os.Exit(1)
+	}
+	l, err := gpt4all.New(model, gpt4all.SetModelType(gpt4all.GPTJType), gpt4all.SetThreads(threads))
+	if err != nil {
+		fmt.Println("Loading the model failed:", err.Error())
+		os.Exit(1)
+	}
+	fmt.Printf("Model loaded successfully.\n")
+
+	l.SetTokenCallback(func(token string) bool {
+		fmt.Print(token)
+		return true
+	})
+
+	reader := bufio.NewReader(os.Stdin)
+
+	for {
+		text := readMultiLineInput(reader)
+
+		_, err := l.Predict(text, gpt4all.SetTokens(tokens), gpt4all.SetTopK(90), gpt4all.SetTopP(0.86))
+		if err != nil {
+			panic(err)
+		}
+		fmt.Printf("\n\n")
+	}
+}
+
+// readMultiLineInput reads input until an empty line is entered.
+func readMultiLineInput(reader *bufio.Reader) string {
+	var lines []string
+	fmt.Print(">>> ")
+
+	for {
+		line, err := reader.ReadString('\n')
+		if err != nil {
+			if err == io.EOF {
+				os.Exit(0)
+			}
+			fmt.Printf("Reading the prompt failed: %s", err)
+			os.Exit(1)
+		}
+
+		if len(strings.TrimSpace(line)) == 0 {
+			break
+		}
+
+		lines = append(lines, line)
+	}
+
+	text := strings.Join(lines, "")
+	return text
+}