Replit Model (#713)

* porting over replit code model to gpt4all

* replaced memory with kv_self struct

* continuing debug

* welp it built but lot of sus things

* working model loading and somewhat working generate.. need to format response?

* revert back to semi working version

* finally got rid of weird formatting

* figured out problem is with python bindings - this is good to go for testing

* addressing PR feedback

* output refactor

* fixed prompt reponse collection

* cleanup

* addressing PR comments

* building replit backend with new ggmlver code

* chatllm replit and clean python files

* cleanup

* updated replit to match new llmodel api

* match llmodel api and change size_t to Token

* resolve PR comments

* replit model commit comment

gpt4all-backend/replit_impl.h

@@ -0,0 +1,40 @@
+#ifndef REPLIT_H_I_KNOW_WHAT_I_AM_DOING_WHEN_INCLUDING_THIS_FILE
+#error This file is NOT meant to be included outside of replit.cpp. Doing so is DANGEROUS. Be sure to know what you are doing before proceeding to #define REPLIT_H_I_KNOW_WHAT_I_AM_DOING_WHEN_INCLUDING_THIS_FILE
+#endif
+#ifndef REPLIT_H
+#define REPLIT_H
+
+#include <string>
+#include <functional>
+#include <vector>
+#include "llmodel.h"
+
+#define GGML_QNT_VERSION_FACTOR 1000 // do not change this
+
+struct ReplitPrivate;
+class Replit : public LLModel {
+public:
+    Replit();
+    ~Replit();
+
+    bool loadModel(const std::string &modelPath) override;
+    bool isModelLoaded() const override;
+    size_t stateSize() const override;
+    size_t saveState(uint8_t *dest) const override;
+    size_t restoreState(const uint8_t *src) override;
+    void setThreadCount(int32_t n_threads) override;
+    int32_t threadCount() const override;
+
+private:
+    ReplitPrivate *d_ptr;
+
+protected:
+    std::vector<Token> tokenize(PromptContext &, const std::string&) const override;
+    std::string_view tokenToString(Token) const override;
+    Token sampleToken(PromptContext &ctx) const override;
+    bool evalTokens(PromptContext &ctx, const std::vector<int32_t> &tokens) const override;
+    int32_t contextLength() const override;
+    const std::vector<Token>& endTokens() const override;
+};
+
+#endif // REPLIT_H