sampling : refactor init to use llama_sampling_params (#3696)

* sampling : refactor init to use llama_sampling_params

* llama : combine repetition, frequency and presence penalties in 1 call

* examples : remove embd-input and gptneox-wip

* sampling : rename penalty params + reduce size of "prev" vector

* sampling : add llama_sampling_print helper

* sampling : hide prev behind API and apply #3661

ggml-ci

common/sampling.h

@@ -10,30 +10,30 @@
 
 // sampling parameters
 typedef struct llama_sampling_params {
+    int32_t n_prev            = 64;    // number of previous tokens to remember
+    int32_t n_probs           = 0;     // if greater than 0, output the probabilities of top n_probs tokens.
     int32_t top_k             = 40;    // <= 0 to use vocab size
     float   top_p             = 0.95f; // 1.0 = disabled
     float   tfs_z             = 1.00f; // 1.0 = disabled
     float   typical_p         = 1.00f; // 1.0 = disabled
     float   temp              = 0.80f; // 1.0 = disabled
-    float   repeat_penalty    = 1.10f; // 1.0 = disabled
-    int32_t repeat_last_n     = 64;    // last n tokens to penalize (0 = disable penalty, -1 = context size)
-    float   frequency_penalty = 0.00f; // 0.0 = disabled
-    float   presence_penalty  = 0.00f; // 0.0 = disabled
+    int32_t penalty_last_n    = 64;    // last n tokens to penalize (0 = disable penalty, -1 = context size)
+    float   penalty_repeat    = 1.10f; // 1.0 = disabled
+    float   penalty_freq      = 0.00f; // 0.0 = disabled
+    float   penalty_present   = 0.00f; // 0.0 = disabled
     int32_t mirostat          = 0;     // 0 = disabled, 1 = mirostat, 2 = mirostat 2.0
     float   mirostat_tau      = 5.00f; // target entropy
     float   mirostat_eta      = 0.10f; // learning rate
-
     bool    penalize_nl       = true;  // consider newlines as a repeatable token
 
-    int32_t n_probs           = 0;     // if greater than 0, output the probabilities of top n_probs tokens.
+    std::string grammar;  // optional BNF-like grammar to constrain sampling
 
     // Classifier-Free Guidance
     // https://arxiv.org/abs/2306.17806
-    std::string cfg_negative_prompt;   // string to help guidance
-    float       cfg_scale     = 1.f;   // How strong is guidance
+    std::string cfg_negative_prompt; // string to help guidance
+    float       cfg_scale     = 1.f; // how strong is guidance
 
     std::unordered_map<llama_token, float> logit_bias; // logit bias for specific tokens
-
 } llama_sampling_params;
 
 // general sampler context
@@ -58,7 +58,7 @@ struct llama_sampling_context {
 #include "common.h"
 
 // Create a new sampling context instance.
-struct llama_sampling_context * llama_sampling_init(const struct gpt_params & params);
+struct llama_sampling_context * llama_sampling_init(const struct llama_sampling_params & params);
 
 void llama_sampling_free(struct llama_sampling_context * ctx);
 
@@ -70,6 +70,15 @@ void llama_sampling_reset(llama_sampling_context * ctx);
 // Copy the sampler context
 void llama_sampling_cp(llama_sampling_context * src, llama_sampling_context * dst);
 
+// Get the last sampled token
+llama_token llama_sampling_last(llama_sampling_context * ctx);
+
+// Get a string representation of the last sampled tokens
+std::string llama_sampling_prev_str(llama_sampling_context * ctx_sampling, llama_context * ctx_main, int n);
+
+// Print sampling parameters into a string
+std::string llama_sampling_print(const llama_sampling_params & params);
+
 // this is a common sampling function used across the examples for convenience
 // it can serve as a starting point for implementing your own sampling function
 // Note: When using multiple sequences, it is the caller's responsibility to call
@@ -96,4 +105,5 @@ llama_token llama_sampling_sample(
 void llama_sampling_accept(
         struct llama_sampling_context * ctx_sampling,
         struct llama_context * ctx_main,
-        llama_token id);
+        llama_token id,
+        bool apply_grammar);