Add string rules

src/rules.h

@@ -7,5 +7,6 @@
 #include "rules/symbol.h"
 #include "rules/choice.h"
 #include "rules/seq.h"
+#include "rules/string.h"
 
 #endif

src/rules/char.cpp

@@ -21,7 +21,7 @@ namespace tree_sitter  {
         }
         
         string Char::to_string() const {
-            return std::to_string(value);
+            return std::string("'") + &value + "'";
         }
     }
 }

src/rules/string.cpp

@@ -0,0 +1,31 @@
+#include "string.h"
+#include "transition_map.h"
+#include "char.h"
+#include "seq.h"
+
+namespace tree_sitter  {
+    namespace rules {
+        String::String(std::string value) : value(value) {};
+        
+        TransitionMap<Rule> String::transitions() const {
+            rule_ptr result = rule_ptr(new Char(value[0]));
+            for (int i = 1; i < value.length(); i++) {
+                result = rule_ptr(new Seq(result, rule_ptr(new Char(value[i]))));
+            }
+            return result->transitions();
+        }
+        
+        bool String::operator==(const Rule &rule) const {
+            const String *other = dynamic_cast<const String *>(&rule);
+            return (other != NULL) && (other->value == value);
+        }
+        
+        String * String::copy() const {
+            return new String(value);
+        }
+        
+        std::string String::to_string() const {
+            return value;
+        }        
+    }
+}

src/rules/string.h

@@ -0,0 +1,21 @@
+#ifndef __tree_sitter__string__
+#define __tree_sitter__string__
+
+#include "rule.h"
+
+namespace tree_sitter  {
+    namespace rules {
+        class String : public Rule {
+        public:
+            String(std::string value);
+            TransitionMap<Rule> transitions() const;
+            String * copy() const;
+            bool operator==(const Rule& other) const;
+            std::string to_string() const;
+        private:
+            std::string value;
+        };
+    }
+}
+
+#endif