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1 files changed, 194 insertions, 0 deletions

diff --git a/llama.cpp/src/llama-grammar.h b/llama.cpp/src/llama-grammar.h
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+++ b/llama.cpp/src/llama-grammar.h
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+#pragma once
+
+#include "llama.h"
+
+#include <map>
+#include <regex>
+#include <string>
+#include <vector>
+
+struct llama_vocab;
+
+// grammar element type
+enum llama_gretype {
+    // end of rule definition
+    LLAMA_GRETYPE_END            = 0,
+
+    // start of alternate definition for rule
+    LLAMA_GRETYPE_ALT            = 1,
+
+    // non-terminal element: reference to rule
+    LLAMA_GRETYPE_RULE_REF       = 2,
+
+    // terminal element: character (code point)
+    LLAMA_GRETYPE_CHAR           = 3,
+
+    // inverse char(s) ([^a], [^a-b] [^abc])
+    LLAMA_GRETYPE_CHAR_NOT       = 4,
+
+    // modifies a preceding LLAMA_GRETYPE_CHAR or LLAMA_GRETYPE_CHAR_ALT to
+    // be an inclusive range ([a-z])
+    LLAMA_GRETYPE_CHAR_RNG_UPPER = 5,
+
+    // modifies a preceding LLAMA_GRETYPE_CHAR or
+    // LLAMA_GRETYPE_CHAR_RNG_UPPER to add an alternate char to match ([ab], [a-zA])
+    LLAMA_GRETYPE_CHAR_ALT       = 6,
+
+    // any character (.)
+    LLAMA_GRETYPE_CHAR_ANY       = 7,
+
+    // terminal element: token (<[token-id]>)
+    LLAMA_GRETYPE_TOKEN          = 8,
+
+    // inverse token (!<[token-id]>)
+    LLAMA_GRETYPE_TOKEN_NOT      = 9,
+};
+
+typedef struct llama_grammar_element {
+    enum llama_gretype type;
+    uint32_t           value; // Unicode code point, rule ID, or token ID
+} llama_grammar_element;
+
+struct llama_partial_utf8 {
+    uint32_t value;    // bit value so far (unshifted)
+    int      n_remain; // num bytes remaining; -1 indicates invalid sequence
+};
+
+struct llama_grammar_candidate {
+    size_t               index;
+    const uint32_t     * code_points;
+    llama_partial_utf8   partial_utf8;
+    llama_token          id;
+};
+
+using llama_grammar_rule  = std::vector<      llama_grammar_element>;
+using llama_grammar_stack = std::vector<const llama_grammar_element *>;
+
+using llama_grammar_rules      = std::vector<llama_grammar_rule>;
+using llama_grammar_stacks     = std::vector<llama_grammar_stack>;
+using llama_grammar_candidates = std::vector<llama_grammar_candidate>;
+
+// TODO: remove, needed for tests atm
+const llama_grammar_rules  & llama_grammar_get_rules (const struct llama_grammar * grammar);
+      llama_grammar_stacks & llama_grammar_get_stacks(      struct llama_grammar * grammar);
+
+// takes a set of possible pushdown stacks on a grammar, which are required to
+// be positioned at a character range (see `llama_grammar_advance_stack`), and
+// produces the N possible stacks if the given char is accepted at those
+// positions
+void llama_grammar_accept(struct llama_grammar * grammar, uint32_t chr);
+
+std::vector<llama_grammar_candidate> llama_grammar_reject_candidates_for_stack(
+        const llama_grammar_rules      & rules,
+        const llama_grammar_stack      & stack,
+        const llama_grammar_candidates & candidates);
+
+struct llama_grammar_parser {
+    const llama_vocab * vocab;
+    std::map<std::string, uint32_t> symbol_ids;
+
+    llama_grammar_rules rules;
+
+    llama_grammar_parser(const struct llama_vocab * vocab = nullptr) : vocab(vocab) {}
+
+    llama_grammar_stack c_rules() const;
+
+    uint32_t get_symbol_id(const char * src, size_t len);
+    uint32_t generate_symbol_id(const std::string & base_name);
+
+    void add_rule(uint32_t rule_id, const llama_grammar_rule & rule);
+
+    const char * parse_alternates(
+            const char        * src,
+            const std::string & rule_name,
+            uint32_t            rule_id,
+            bool                is_nested);
+
+    const char * parse_sequence(
+            const char         * src,
+            const std::string  & rule_name,
+            llama_grammar_rule & rule,
+            bool               is_nested);
+
+    const char * parse_rule(const char * src);
+
+    bool parse(const char * src);
+    void print(FILE * file);
+};
+
+struct llama_grammar_trigger_pattern {
+    std::string pattern;
+    std::regex  regex;
+
+    size_t find(const std::string & input) const;
+};
+
+struct llama_grammar {
+    // maintain a list of llama_tokens and their positions in the trigger_buffer
+    using token_pos = std::pair<llama_token, std::pair<size_t, size_t>>;
+
+    // note: allow null vocab for testing (not great)
+    const llama_vocab * vocab;
+
+    const llama_grammar_rules  rules;  // TODO: shared ptr
+          llama_grammar_stacks stacks;
+
+    // buffer for partially generated UTF-8 sequence from accepted tokens
+    llama_partial_utf8 partial_utf8;
+
+    // lazy grammars wait for trigger words or tokens before constraining the sampling.
+    // we still have trigger_tokens for non-lazy grammars to force printing of special trigger tokens.
+    // (useful e.g. for tool_choice=required)
+    bool                     lazy             = false;
+    bool                     awaiting_trigger = false; // Initialized to true for lazy grammars only
+    std::string              trigger_buffer;           // Output buffered by lazy grammar. Will be cleared once trigger is found.
+    std::vector<token_pos>   trigger_buffer_positions; // Tokens buffered by lazy grammar. Used to replay when a trigger is found.
+    std::vector<llama_token> trigger_tokens;           // Tokens that trigger a lazy grammar, or tokens to force printing of (even if special).
+    std::vector<llama_grammar_trigger_pattern>
+                             trigger_patterns;         // Regular expressions that trigger a lazy grammar. Must be a full match of the entire generated
+                                                       // string, and the grammar will be given the string from the first match group onwards.
+
+};
+
+//
+// internal API
+//
+
+// note: needed for tests (not great)
+struct llama_grammar * llama_grammar_init_impl(
+        const struct llama_vocab * vocab,
+        const llama_grammar_element ** rules,
+        size_t n_rules,
+        size_t start_rule_index);
+
+struct llama_grammar * llama_grammar_init_impl(
+        const struct llama_vocab * vocab,
+                      const char * grammar_str,
+                      const char * grammar_root,
+                              bool lazy,
+                     const char ** trigger_patterns,
+                            size_t num_trigger_patterns,
+               const llama_token * trigger_tokens,
+                            size_t num_trigger_tokens);
+
+void llama_grammar_free_impl(struct llama_grammar * grammar);
+
+struct llama_grammar * llama_grammar_clone_impl(const struct llama_grammar & grammar);
+
+// TODO: move the API below as member functions of llama_grammar
+void llama_grammar_apply_impl(
+        const struct llama_grammar & grammar,
+            llama_token_data_array * cur_p);
+
+void llama_grammar_accept_impl(
+              struct llama_grammar & grammar,
+                       llama_token   token);
+
+void llama_grammar_accept_str(
+              struct llama_grammar & grammar,
+                 const std::string & piece);
+
+void llama_grammar_accept_token(
+              struct llama_grammar & grammar,
+                       llama_token   token,
+                 const std::string & piece);