src/lexer.cpp

@@ -2,20 +2,33 @@
 
 #include <iostream>
 
+obelisk::Lexer::Lexer(const std::string& sourceFile)
+{
+    fileStream_.open(sourceFile, std::ifstream::in);
+    if (!fileStream_)
+    {
+        throw obelisk::LexerException("could not open source file " + sourceFile);
+    }
+}
+
+obelisk::Lexer::~Lexer()
+{
+    fileStream_.close();
+    fileStream_.clear();
+}
+
 int obelisk::Lexer::getToken()
 {
-    static int lastChar = ' ';
-
     while (isspace(lastChar))
     {
-        lastChar = std::getc(stdin);
+        lastChar = fileStream_.get();
     }
 
     if (isalpha(lastChar))
     {
         eraseIdentifier();
         appendIdentifier(lastChar);
-        while (isalnum((lastChar = getchar())))
+        while (isalnum((lastChar = fileStream_.get())))
         {
             appendIdentifier(lastChar);
         }
@@ -63,7 +76,7 @@ int obelisk::Lexer::getToken()
                 firstPeriod = true;
             }
             numberStr += lastChar;
-            lastChar = getchar();
+            lastChar = fileStream_.get();
         }
         while (isdigit(lastChar) || lastChar == '.');
 
@@ -83,7 +96,7 @@ int obelisk::Lexer::getToken()
     }
     else if (lastChar == '/')
     {
-        lastChar = getchar();
+        lastChar = fileStream_.get();
         if (lastChar == '/')
         {
             commentLine(&lastChar);
@@ -101,7 +114,7 @@ int obelisk::Lexer::getToken()
     }
 
     int thisChar = lastChar;
-    lastChar     = getchar();
+    lastChar     = fileStream_.get();
     return thisChar;
 }
 
@@ -109,7 +122,7 @@ void obelisk::Lexer::commentLine(int* lastChar)
 {
     do
     {
-        *lastChar = getchar();
+        *lastChar = fileStream_.get();
     }
     while (*lastChar != EOF && *lastChar != '\n' && *lastChar != '\r');
 }

src/lexer.h

@@ -1,6 +1,7 @@
 #ifndef OBELISK_LEXER_H
 #define OBELISK_LEXER_H
 
+#include <fstream>
 #include <string>
 
 namespace obelisk
@@ -12,6 +13,12 @@ namespace obelisk
     class Lexer
     {
         private:
+            int lastChar = ' ';
+            /**
+             * @brief The stream of the source file being read.
+             *
+             */
+            std::ifstream fileStream_;
             /**
              * @brief The last found identifier.
              *
@@ -21,7 +28,7 @@ namespace obelisk
              * @brief The last found number.
              *
              */
-            double numberValue_;
+            double numberValue_ = 0;
 
             /**
              * @brief Set the identifier.
@@ -113,6 +120,19 @@ namespace obelisk
                 kTokenString     = -9
             };
 
+            /**
+             * @brief Construct a new Lexer object.
+             *
+             * @param[in] sourceFile The source file to read.
+             */
+            Lexer(const std::string& sourceFile);
+
+            /**
+             * @brief Destroy the Lexer object.
+             *
+             */
+            ~Lexer();
+
             /**
              * @brief Gets the next token in the source code.
              *

src/models/fact.cpp

@@ -7,8 +7,8 @@ const char* obelisk::Fact::createTable()
         CREATE TABLE "fact" (
             "id"           INTEGER NOT NULL UNIQUE,
             "left_entity"  INTEGER NOT NULL,
-            "right_entity" INTEGER NOT NULL,
             "verb"         INTEGER NOT NULL,
+            "right_entity" INTEGER NOT NULL,
             "is_true"      INTEGER NOT NULL DEFAULT 0,
             PRIMARY KEY("id" AUTOINCREMENT),
             UNIQUE("left_entity", "right_entity", "verb")

src/obelisk.cpp

@@ -9,9 +9,8 @@
 #include <limits>
 #include <memory>
 
-static int obelisk::mainLoop(const std::vector<std::string>& sourceFiles, const std::string& kbFile)
+int obelisk::mainLoop(const std::vector<std::string>& sourceFiles, const std::string& kbFile)
 {
-    auto parser = std::unique_ptr<obelisk::Parser> {new obelisk::Parser()};
     std::unique_ptr<obelisk::KnowledgeBase> kb;
 
     try
@@ -24,8 +23,20 @@ static int obelisk::mainLoop(const std::vector<std::string>& sourceFiles, const
         return EXIT_FAILURE;
     }
 
-    // Prime the first token.
-    fprintf(stderr, "ready> ");
+    size_t file = 0;
+    std::shared_ptr<obelisk::Lexer> lexer;
+    try
+    {
+        lexer = std::shared_ptr<obelisk::Lexer> {new obelisk::Lexer(sourceFiles[file++])};
+    }
+    catch (obelisk::LexerException& exception)
+    {
+        std::cout << exception.what() << std::endl;
+        return EXIT_FAILURE;
+    }
+    auto parser = std::unique_ptr<obelisk::Parser> {new obelisk::Parser(lexer)};
+
+    // prime the first token
     try
     {
         parser->getNextToken();
@@ -38,14 +49,29 @@ static int obelisk::mainLoop(const std::vector<std::string>& sourceFiles, const
 
     while (true)
     {
-        fprintf(stderr, "ready> ");
         switch (parser->getCurrentToken())
         {
             case obelisk::Lexer::kTokenEof :
-                return EXIT_SUCCESS;
-            case ';' : // ignore top-level semicolons.
-                std::cout << "Identifier: " << parser->getLexer()->getIdentifier() << std::endl;
-                std::cout << "Num: " << parser->getLexer()->getNumberValue() << std::endl;
+                // end of source file found, create a new lexer and pass it to the parser to use
+                if (file >= sourceFiles.size())
+                {
+                    return EXIT_SUCCESS;
+                }
+                try
+                {
+                    lexer = std::shared_ptr<obelisk::Lexer> {new obelisk::Lexer(sourceFiles[file++])};
+                    parser->setLexer(lexer);
+                    // prime the first token in the parser
+                    parser->getNextToken();
+                }
+                catch (obelisk::LexerException& exception)
+                {
+                    std::cout << exception.what() << std::endl;
+                    return EXIT_FAILURE;
+                }
+                break;
+            case ';' :
+                // semicolon found, the end of a statement
                 try
                 {
                     parser->getNextToken();
@@ -74,7 +100,7 @@ static int obelisk::mainLoop(const std::vector<std::string>& sourceFiles, const
     return EXIT_SUCCESS;
 }
 
-void obelisk::showUsage()
+static void obelisk::showUsage()
 {
     std::cout << obelisk::usageMessage << std::endl;
 }
@@ -126,10 +152,5 @@ int main(int argc, char** argv)
         return EXIT_FAILURE;
     }
 
-    std::cout << sourceFiles[0] << std::endl;
-    std::cout << kbFile << std::endl;
-
-    return 0;
-
     return obelisk::mainLoop(sourceFiles, kbFile);
 }

src/obelisk.h

@@ -42,5 +42,5 @@ Options:
      *
      * @return int Returns EXIT_SUCCESS or EXIT_FAILURE.
      */
-    static int mainLoop(const std::vector<std::string> &sourceFiles, const std::string &kbFile);
+    int mainLoop(const std::vector<std::string> &sourceFiles, const std::string &kbFile);
 } // namespace obelisk

src/parser.cpp

@@ -11,16 +11,17 @@
 #include <string>
 #include <vector>
 
-obelisk::Parser::Parser()
-{
-    lexer_ = std::unique_ptr<obelisk::Lexer> {new obelisk::Lexer()};
-}
-
-std::unique_ptr<obelisk::Lexer>& obelisk::Parser::getLexer()
+std::shared_ptr<obelisk::Lexer> obelisk::Parser::getLexer()
 {
     return lexer_;
 }
 
+void obelisk::Parser::setLexer(std::shared_ptr<obelisk::Lexer> lexer)
+{
+    lexer_        = lexer;
+    currentToken_ = 0;
+}
+
 int obelisk::Parser::getNextToken()
 {
     try

src/parser.h

@@ -15,8 +15,8 @@ namespace obelisk
     class Parser
     {
         private:
-            std::unique_ptr<obelisk::Lexer> lexer_;
-            int currentToken_;
+            std::shared_ptr<obelisk::Lexer> lexer_;
+            int currentToken_ = 0;
 
             void setCurrentToken(int currentToken);
 
@@ -37,9 +37,13 @@ namespace obelisk
             void parseFact(std::vector<obelisk::Fact>& facts);
 
         public:
-            Parser();
+            Parser(std::shared_ptr<obelisk::Lexer> lexer) :
+                lexer_(lexer)
+            {
+            }
 
-            std::unique_ptr<obelisk::Lexer>& getLexer();
+            std::shared_ptr<obelisk::Lexer> getLexer();
+            void setLexer(std::shared_ptr<obelisk::Lexer> lexer);
 
             int getCurrentToken();