Start work on lexing

src/compiler/lr/lex_table.cpp

@@ -0,0 +1,67 @@
+#include "lex_table.h"
+
+using std::string;
+using std::to_string;
+using std::unordered_map;
+using std::unordered_set;
+using std::vector;
+
+namespace tree_sitter {
+    namespace lr {
+
+        // Action
+        LexAction::LexAction(LexActionType type, size_t state_index, std::string symbol_name) :
+            type(type),
+            state_index(state_index),
+            symbol_name(symbol_name) {}
+        
+        LexAction LexAction::Error() {
+            return LexAction(LexActionTypeError, -1, "");
+        }
+        
+        LexAction LexAction::Advance(size_t state_index) {
+            return LexAction(LexActionTypeAdvance, state_index, "");
+        }
+        
+        LexAction LexAction::Accept(std::string symbol_name) {
+            return LexAction(LexActionTypeAccept, -1, symbol_name);
+        }
+        
+        bool LexAction::operator==(const LexAction &other) const {
+            return
+                (type == other.type) &&
+                (state_index == other.state_index) &&
+                (symbol_name == other.symbol_name);
+        }
+        
+        std::ostream& operator<<(std::ostream &stream, const LexAction &action) {
+            switch (action.type) {
+                case LexActionTypeError:
+                    return stream << string("(error)");
+                case LexActionTypeAccept:
+                    return stream << string("(accept ") + action.symbol_name + ")";
+                case LexActionTypeAdvance:
+                    return stream << string("(advance ") + to_string(action.state_index) + ")";
+            }
+        }
+        
+        // State
+        LexState::LexState() : actions(unordered_map<CharMatch, unordered_set<LexAction>>()) {}
+
+        // Table
+        LexTable::LexTable(vector<string> rule_names) : symbol_names(rule_names) {}
+
+        size_t LexTable::add_state() {
+            states.push_back(LexState());
+            return states.size() - 1;
+        }
+        
+        void LexTable::add_action(size_t state_index, CharMatch match, LexAction action) {
+            states[state_index].actions[match].insert(action);
+        }
+
+        void LexTable::add_default_action(size_t state_index, LexAction action) {
+            states[state_index].default_actions.insert(action);
+        }
+    }
+}