diff --git a/examples/grammars/json.hpp b/examples/grammars/json.hpp
index 9a5e6cf5..9bd1364d 100644
--- a/examples/grammars/json.hpp
+++ b/examples/grammars/json.hpp
@@ -36,12 +36,12 @@ namespace test_grammars {
                 comma_sep(sym("value")),
                 _sym("right_bracket"), }) },
             { "string", seq({
-                character({ '"' }),
+                str("\""),
                 repeat(choice({
                     pattern("[^\"]"),
                     str("\\\""),
                 })),
-                character({ '"' }) }) },
+                str("\"") }) },
             { "number", pattern("\\d+") },
             { "comma", str(",") },
             { "colon", str(":") },
diff --git a/include/tree_sitter/compiler.h b/include/tree_sitter/compiler.h
index dbd72e4e..8e1c5767 100644
--- a/include/tree_sitter/compiler.h
+++ b/include/tree_sitter/compiler.h
@@ -3,7 +3,6 @@
 
 #include <vector>
 #include <map>
-#include <set>
 #include <string>
 #include <memory>
 
@@ -11,47 +10,20 @@ namespace tree_sitter {
     namespace rules {
         class Rule;
         class Symbol;
-        
-        struct CharacterRange {
-            char min;
-            char max;
-            CharacterRange(char);
-            CharacterRange(char, char);
-            bool operator==(const CharacterRange &) const;
-            bool operator<(const CharacterRange &) const;
-            std::string to_string() const;
-        };
-    }
-}
-
-namespace std {
-    template<>
-    struct hash<tree_sitter::rules::CharacterRange> {
-        size_t operator()(const tree_sitter::rules::CharacterRange &range) const {
-            return (hash<char>()(range.min) ^ hash<char>()(range.max));
-        }
-    };
-}
-
-namespace tree_sitter {
-    namespace rules {
         typedef std::shared_ptr<Rule> rule_ptr;
+        
         std::ostream& operator<<(std::ostream& stream, const rule_ptr &rule);
         
         rule_ptr blank();
-        rule_ptr character(const std::set<CharacterRange> &matches);
-        rule_ptr character(const std::set<CharacterRange> &matches, bool);
         rule_ptr choice(const std::vector<rule_ptr> &rules);
-        rule_ptr pattern(const std::string &value);
         rule_ptr repeat(const rule_ptr content);
         rule_ptr seq(const std::vector<rule_ptr> &rules);
-        rule_ptr str(const std::string &value);
         rule_ptr sym(const std::string &name);
         rule_ptr _sym(const std::string &name);
+        rule_ptr pattern(const std::string &value);
+        rule_ptr str(const std::string &value);
     }
-}
 
-namespace tree_sitter {
     class Grammar {
     public:
         Grammar(std::string start_rule_name, const std::map<const std::string, const rules::rule_ptr> &rules);
@@ -61,7 +33,7 @@ namespace tree_sitter {
     };
     
     std::ostream& operator<<(std::ostream &stream, const Grammar &grammar);
-    
+
     std::string compile(const Grammar &grammar, std::string name);
 }
 
diff --git a/spec/spec_helper.cpp b/spec/spec_helper.cpp
index dae44a92..0266266c 100644
--- a/spec/spec_helper.cpp
+++ b/spec/spec_helper.cpp
@@ -1,7 +1,23 @@
 #include "spec_helper.h"
+#include "rules/character_set.h"
 
 string src_dir() {
     const char * dir = getenv("TREESITTER_DIR");
     if (!dir) dir = getenv("PWD");
     return dir;
+}
+
+namespace tree_sitter {
+    namespace rules {
+        rule_ptr character(const set<CharacterRange> &ranges) {
+            return make_shared<CharacterSet>(ranges);
+        }
+        
+        rule_ptr character(const set<CharacterRange> &ranges, bool sign) {
+            if (sign)
+                return character(ranges);
+            else
+                return CharacterSet(ranges).complement().copy();
+        }
+    }
 }
\ No newline at end of file
diff --git a/spec/spec_helper.h b/spec/spec_helper.h
index 8deb0e52..954be878 100644
--- a/spec/spec_helper.h
+++ b/spec/spec_helper.h
@@ -6,6 +6,7 @@
 #include "helpers/equals_pointer.h"
 #include "tree_sitter/compiler.h"
 #include "tree_sitter/runtime.h"
+#include "rules/character_range.h"
 
 using namespace tree_sitter;
 using namespace std;
@@ -16,4 +17,11 @@ using namespace bandit;
 
 string src_dir();
 
+namespace tree_sitter {
+    namespace rules {
+        rule_ptr character(const std::set<CharacterRange> &matches);
+        rule_ptr character(const std::set<CharacterRange> &matches, bool);
+    }
+}
+
 #endif
diff --git a/src/compiler/rules/character_range.cpp b/src/compiler/rules/character_range.cpp
index 635583d6..b654ad90 100644
--- a/src/compiler/rules/character_range.cpp
+++ b/src/compiler/rules/character_range.cpp
@@ -1,4 +1,5 @@
-#include "tree_sitter/compiler.h"
+#include "character_range.h"
+#include <string>
 
 namespace tree_sitter {
     using std::string;
diff --git a/src/compiler/rules/character_range.h b/src/compiler/rules/character_range.h
new file mode 100644
index 00000000..bb6fe2db
--- /dev/null
+++ b/src/compiler/rules/character_range.h
@@ -0,0 +1,29 @@
+#ifndef __tree_sitter_character_range_h__
+#define __tree_sitter_character_range_h__
+
+#include <map>
+
+namespace tree_sitter {
+    namespace rules {
+        struct CharacterRange {
+            char min;
+            char max;
+            CharacterRange(char);
+            CharacterRange(char, char);
+            bool operator==(const CharacterRange &) const;
+            bool operator<(const CharacterRange &) const;
+            std::string to_string() const;
+        };
+    }
+}
+
+namespace std {
+    template<>
+    struct hash<tree_sitter::rules::CharacterRange> {
+        size_t operator()(const tree_sitter::rules::CharacterRange &range) const {
+            return (hash<char>()(range.min) ^ hash<char>()(range.max));
+        }
+    };
+}
+
+#endif
diff --git a/src/compiler/rules/character_set.h b/src/compiler/rules/character_set.h
index 98734df8..975df757 100644
--- a/src/compiler/rules/character_set.h
+++ b/src/compiler/rules/character_set.h
@@ -1,8 +1,8 @@
 #ifndef __tree_sitter__character_set__
 #define __tree_sitter__character_set__
 
-#include "tree_sitter/compiler.h"
 #include "rule.h"
+#include "./character_range.h"
 #include <set>
 #include <initializer_list>
 
diff --git a/src/compiler/rules/rules.cpp b/src/compiler/rules/rules.cpp
index db7352b6..68f78e7e 100644
--- a/src/compiler/rules/rules.cpp
+++ b/src/compiler/rules/rules.cpp
@@ -20,17 +20,6 @@ namespace tree_sitter {
             return make_shared<Blank>();
         }
   
-        rule_ptr character(const set<CharacterRange> &ranges) {
-            return make_shared<CharacterSet>(ranges);
-        }
-
-        rule_ptr character(const set<CharacterRange> &ranges, bool sign) {
-            if (sign)
-                return character(ranges);
-            else
-                return CharacterSet(ranges).complement().copy();
-        }
-
         rule_ptr choice(const vector<rule_ptr> &rules) {
             return Choice::Build(rules);
         }
diff --git a/tree_sitter.xcodeproj/project.pbxproj b/tree_sitter.xcodeproj/project.pbxproj
index 6c50a75e..a1ba2c9f 100644
--- a/tree_sitter.xcodeproj/project.pbxproj
+++ b/tree_sitter.xcodeproj/project.pbxproj
@@ -105,6 +105,7 @@
 		1236A7CE18B3CC4800593ABB /* .travis.yml */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text; path = .travis.yml; sourceTree = "<group>"; };
 		1236A7D018B554C800593ABB /* prepared_grammar.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = prepared_grammar.cpp; sourceTree = "<group>"; };
 		1236A7D118B554C800593ABB /* prepared_grammar.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = prepared_grammar.h; sourceTree = "<group>"; };
+		1236A7D418B72EB400593ABB /* character_range.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = character_range.h; sourceTree = "<group>"; };
 		1251209A1830145300C9B56A /* rule.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = rule.cpp; sourceTree = "<group>"; };
 		125120A3183083BD00C9B56A /* arithmetic.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; lineEnding = 0; path = arithmetic.hpp; sourceTree = "<group>"; xcLanguageSpecificationIdentifier = xcode.lang.cpp; };
 		12661BF318A1505A00A259FB /* character_set_spec.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = character_set_spec.cpp; path = spec/compiler/rules/character_set_spec.cpp; sourceTree = SOURCE_ROOT; };
@@ -198,6 +199,7 @@
 				1213060F182C3A1100FCF928 /* blank.cpp */,
 				12130610182C3A1100FCF928 /* blank.h */,
 				1236A7C318B287DC00593ABB /* character_range.cpp */,
+				1236A7D418B72EB400593ABB /* character_range.h */,
 				12130603182C348F00FCF928 /* character_set.cpp */,
 				12130604182C348F00FCF928 /* character_set.h */,
 				1213060C182C398300FCF928 /* choice.cpp */,