Organize source into compiler and runtime dirs

src/compiler/rules/choice.cpp

@@ -0,0 +1,32 @@
+#include "choice.h"
+#include "transition_map.h"
+
+namespace tree_sitter  {
+    namespace rules {
+        Choice::Choice(rule_ptr left, rule_ptr right) : left(left), right(right) {};
+        
+        rule_ptr choice(const std::initializer_list<rule_ptr> &rules) {
+            rule_ptr result;
+            for (auto rule : rules)
+                result = result.get() ? std::make_shared<Choice>(result, rule) : rule;
+            return result;
+        }
+
+        TransitionMap<Rule> Choice::transitions() const {
+            auto result = left->transitions();
+            result.merge(right->transitions(), [&](rule_ptr left, rule_ptr right) -> rule_ptr {
+                return choice({ left, right });
+            });
+            return result;
+        }
+
+        bool Choice::operator==(const Rule &rule) const {
+            const Choice *other = dynamic_cast<const Choice *>(&rule);
+            return other && (*other->left == *left) && (*other->right == *right);
+        }
+
+        std::string Choice::to_string() const {
+            return std::string("(choice ") + left->to_string() + " " + right->to_string() + ")";
+        }
+    }
+}