Consolidate logic for making shared pointers to rules

src/compiler/rules/rules.cpp

@@ -0,0 +1,53 @@
+#include "rules.h"
+
+using std::make_shared;
+using std::string;
+using std::initializer_list;
+
+namespace tree_sitter {
+    namespace rules {
+        rule_ptr blank() {
+            return make_shared<Blank>();
+        }
+  
+        rule_ptr character(char value) {
+            return make_shared<Char>(value);
+        }
+        
+        rule_ptr char_class(CharClassType type) {
+            return make_shared<CharClass>(type);
+        }
+        
+        rule_ptr choice(const initializer_list<rule_ptr> &rules) {
+            rule_ptr result;
+            for (auto rule : rules)
+                result = result.get() ? make_shared<Choice>(result, rule) : rule;
+            return result;
+        }
+        
+        rule_ptr pattern(const string &value) {
+            return make_shared<Pattern>(value);
+        }
+        
+        rule_ptr repeat(const rule_ptr content) {
+            return std::make_shared<Repeat>(content);
+        }
+        
+        rule_ptr seq(const initializer_list<rule_ptr> &rules) {
+            rule_ptr result = blank();
+            for (auto rule : rules)
+                result = (typeid(*result) != typeid(Blank)) ?
+                    make_shared<Seq>(result, rule) :
+                    rule;
+            return result;
+        }
+
+        rule_ptr str(const string &value) {
+            return make_shared<String>(value);
+        }
+
+        rule_ptr sym(const string &name) {
+            return make_shared<Symbol>(name);
+        }
+    }
+}