crib/include/syntax/decl.h

#ifndef SYNTAX_DECL_H
#define SYNTAX_DECL_H

#include "io/knot.h"
#include "io/sysio.h"

struct Trie {
  struct TrieNode {
    bool is_word = false;
    std::array<TrieNode *, 128> children{};
    TrieNode() { children.fill(nullptr); }
  };

  Trie() : root(new TrieNode()) {}
  ~Trie() { clear_trie(root); }

  void build(const std::vector<std::string> &words) {
    for (const auto &word : words) {
      TrieNode *node = root;
      for (char c : word) {
        unsigned char uc = static_cast<unsigned char>(c);
        if (!node->children[uc])
          node->children[uc] = new TrieNode();
        node = node->children[uc];
      }
      node->is_word = true;
    }
  }

  uint32_t match(const char *text, uint32_t pos, uint32_t len,
                 bool (*is_word_char)(char c)) const {
    const TrieNode *node = root;
    uint32_t max_len = 0;
    for (uint32_t i = pos; i < len; ++i) {
      unsigned char uc = static_cast<unsigned char>(text[i]);
      if (uc >= 128)
        return 0;
      if (!node->children[uc]) {
        if (node->is_word && !is_word_char(text[i]))
          return i - pos;
        break;
      }
      node = node->children[uc];
      if (node->is_word)
        max_len = i - pos + 1;
    }
    if (max_len > 0)
      if (pos + max_len < len && is_word_char(text[pos + max_len]))
        return 0;
    return max_len;
  }

  void clear() {
    clear_trie(root);
    root = new TrieNode();
  }

private:
  TrieNode *root;

  void clear_trie(TrieNode *node) {
    if (!node)
      return;
    for (auto *child : node->children)
      clear_trie(child);
    delete node;
  }
};

struct Highlight {
  uint32_t fg;
  uint32_t bg;
  uint8_t flags;
};

enum struct TokenKind : uint8_t {
#define ADD(name) name,
#include "syntax/tokens.def"
#undef ADD
  Count
};

constexpr size_t TOKEN_KIND_COUNT = static_cast<size_t>(TokenKind::Count);

const std::unordered_map<std::string, TokenKind> kind_map = {
#define ADD(name) {#name, TokenKind::name},
#include "syntax/tokens.def"
#undef ADD
};

extern std::array<Highlight, TOKEN_KIND_COUNT> highlights;

inline void load_theme(std::string filename) {
  uint32_t len = 0;
  char *raw = load_file(filename.c_str(), &len);
  if (!raw)
    return;
  std::string data(raw, len);
  free(raw);
  json j = json::parse(data);
  Highlight default_hl = {0xFFFFFF, 0, 0};
  if (j.contains("Default")) {
    auto def = j["Default"];
    if (def.contains("fg") && def["fg"].is_string())
      default_hl.fg = HEX(def["fg"]);
    if (def.contains("bg") && def["bg"].is_string())
      default_hl.bg = HEX(def["bg"]);
    if (def.contains("italic") && def["italic"].get<bool>())
      default_hl.flags |= CF_ITALIC;
    if (def.contains("bold") && def["bold"].get<bool>())
      default_hl.flags |= CF_BOLD;
    if (def.contains("underline") && def["underline"].get<bool>())
      default_hl.flags |= CF_UNDERLINE;
    if (def.contains("strikethrough") && def["strikethrough"].get<bool>())
      default_hl.flags |= CF_STRIKETHROUGH;
  }
  for (auto &hl : highlights)
    hl = default_hl;
  for (auto &[key, value] : j.items()) {
    if (key == "Default")
      continue;
    auto it = kind_map.find(key);
    if (it == kind_map.end())
      continue;
    Highlight hl = {0xFFFFFF, 0, 0};
    if (value.contains("fg") && value["fg"].is_string())
      hl.fg = HEX(value["fg"]);
    if (value.contains("bg") && value["bg"].is_string())
      hl.bg = HEX(value["bg"]);
    if (value.contains("italic") && value["italic"].get<bool>())
      hl.flags |= CF_ITALIC;
    if (value.contains("bold") && value["bold"].get<bool>())
      hl.flags |= CF_BOLD;
    if (value.contains("underline") && value["underline"].get<bool>())
      hl.flags |= CF_UNDERLINE;
    if (value.contains("strikethrough") && value["strikethrough"].get<bool>())
      hl.flags |= CF_STRIKETHROUGH;
    highlights[static_cast<uint8_t>(it->second)] = hl;
  }
}

struct Token {
  uint32_t start;
  uint32_t end;
  TokenKind type;
};

struct LineData {
  std::shared_ptr<void> in_state{nullptr};
  std::vector<Token> tokens;
  std::shared_ptr<void> out_state{nullptr};
};

#endif