create a C wrapper for obelisk

meson.build

@@ -1,4 +1,5 @@
 project('obelisk',
+    'c',
     'cpp',
     version : '1.0.0',
     license : 'BSD-3-Clause',

src/lib/include/obelisk.h

@@ -1,3 +1,6 @@
+#ifndef OBELISK_INCLUDE_OBELISK_H
+#define OBELISK_INCLUDE_OBELISK_H
+
 #include <string>
 
 /**
@@ -15,6 +18,18 @@ namespace obelisk
     class Obelisk
     {
         public:
+            /**
+             * @brief Construct a new Obelisk object.
+             *
+             */
+            Obelisk() = default;
+
+            /**
+             * @brief Destroy the Obelisk object.
+             *
+             */
+            ~Obelisk() = default;
+
             /**
              * @brief Get the obelisk version.
              *
@@ -28,5 +43,34 @@ namespace obelisk
              * @return int The version.
              */
             int getLibVersion();
+
+            /**
+             * @brief Query the Obelisk KnowledgeBase to see if the Fact is true
+             * or not.
+             *
+             * @param[in] leftEntity The left entity.
+             * @param[in] verb The verb.
+             * @param[in] rightEntity The right entity.
+             * @return double Returns a value between 0 and 1 depending on
+             * whether it is true or false.
+             */
+            double query(const std::string& leftEntity,
+                const std::string& verb,
+                const std::string& rightEntity);
+
+            /**
+             * @brief Query the Obelisk KnowledgeBase and return the suggested
+             * action to take.
+             *
+             * @param[in] leftEntity The left entity.
+             * @param[in] verb The verb.
+             * @param[in] rightEntity The right entity.
+             * @return std::string Returns the suggested action.
+             */
+            std::string query_action(const std::string& leftEntity,
+                const std::string& verb,
+                const std::string& rightEntity);
     };
 } // namespace obelisk
+
+#endif

src/lib/include/obelisk_c.h

@@ -0,0 +1,28 @@
+#ifndef OBELISK_INCLUDE_OBELISK_PROGRAM_H
+#define OBELISK_INCLUDE_OBELISK_PROGRAM_H
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+    /**
+     * @brief Get the obelisk version.
+     *
+     * @return const char* Returns a string containing the version. This must be
+     * freed by the caller.
+     */
+    extern const char* obelisk_get_version();
+
+    /**
+     * @brief Get the obelisk library so version.
+     *
+     * @return int Returns the so version.
+     */
+    extern int obelisk_get_lib_version();
+
+#ifdef __cplusplus
+};
+#endif
+
+#endif

src/lib/include/obelisk_wrapper.h

@@ -0,0 +1,45 @@
+#ifndef OBELISK_INCLUDE_OBELISK_WRAPPER_H
+#define OBELISK_INCLUDE_OBELISK_WRAPPER_H
+
+typedef struct CObelisk CObelisk;
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+    /**
+     * @brief Create a obelisk object.
+     *
+     * @return CObelisk* Returns the obelisk object.
+     */
+    CObelisk *create_obelisk();
+
+    /**
+     * @brief Calls the obelisk method getVersion.
+     *
+     * @param[in] p_obelisk The obelisk object pointer.
+     * @return const char* Returns the version. Must be freed by caller.
+     */
+    const char *call_obelisk_getVersion(CObelisk *p_obelisk);
+
+    /**
+     * @brief Calls the obelisk method getLibVersion.
+     *
+     * @param[in] p_obelisk The obelisk object pointer.
+     * @return int Returns the library so version.
+     */
+    int call_obelisk_getLibVersion(CObelisk *p_obelisk);
+
+    /**
+     * @brief Delete a obelisk object.
+     *
+     * @param[in] p_obelisk The obelisk object pointer.
+     */
+    void destroy_obelisk(CObelisk *p_obelisk);
+
+#ifdef __cplusplus
+};
+#endif
+
+#endif

src/lib/meson.build

@@ -10,6 +10,8 @@ subdir('models')
 
 obelisk_lib_sources = files(
     'obelisk.cpp',
+    'obelisk.c',
+    'obelisk_wrapper.cpp',
     'knowledge_base.cpp'
 )
 

src/lib/obelisk.c

@@ -0,0 +1,23 @@
+#include "obelisk_c.h"
+#include "obelisk_wrapper.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+const char* obelisk_get_version()
+{
+    CObelisk* obelisk = create_obelisk();
+    size_t len        = strlen(call_obelisk_getVersion(obelisk)) + 1;
+    char* version     = malloc(len);
+    memcpy(version, call_obelisk_getVersion(obelisk), len);
+    destroy_obelisk(obelisk);
+    return version;
+}
+
+int obelisk_get_lib_version()
+{
+    CObelisk* obelisk = create_obelisk();
+    int version       = call_obelisk_getLibVersion(obelisk);
+    destroy_obelisk(obelisk);
+    return version;
+}

src/lib/obelisk.cpp

@@ -10,3 +10,15 @@ int obelisk::Obelisk::getLibVersion()
 {
     return obelisk::soVersion;
 }
+
+double obelisk::Obelisk::query(const std::string& leftEntity,
+    const std::string& verb,
+    const std::string& rightEntity)
+{
+}
+
+std::string obelisk::Obelisk::query_action(const std::string& leftEntity,
+    const std::string& verb,
+    const std::string& rightEntity)
+{
+}

src/lib/obelisk_wrapper.cpp

@@ -0,0 +1,32 @@
+#include "obelisk.h"
+#include "obelisk_wrapper.h"
+
+extern "C"
+{
+    CObelisk* create_obelisk()
+    {
+        obelisk::Obelisk* obelisk = new obelisk::Obelisk();
+        return reinterpret_cast<CObelisk*>(obelisk);
+    }
+
+    const char* call_obelisk_getVersion(CObelisk* p_obelisk)
+    {
+        obelisk::Obelisk* obelisk
+            = reinterpret_cast<obelisk::Obelisk*>(p_obelisk);
+        return obelisk->getVersion().c_str();
+    }
+
+    int call_obelisk_getLibVersion(CObelisk* p_obelisk)
+    {
+        obelisk::Obelisk* obelisk
+            = reinterpret_cast<obelisk::Obelisk*>(p_obelisk);
+        return obelisk->getLibVersion();
+    }
+
+    void destroy_obelisk(CObelisk* p_obelisk)
+    {
+        obelisk::Obelisk* obelisk
+            = reinterpret_cast<obelisk::Obelisk*>(p_obelisk);
+        delete obelisk;
+    }
+};

src/lib/version.h.in

@@ -1,3 +1,6 @@
+#ifndef OBELISK_VERSION_H
+#define OBELISK_VERSION_H
+
 namespace obelisk
 {
     /**
@@ -14,3 +17,5 @@ namespace obelisk
     const int soVersion = @so_version@;
     // clang-format on
 } // namespace obelisk
+
+#endif

src/main.h

@@ -1,3 +1,6 @@
+#ifndef OBELISK_MAIN_H
+#define OBELISK_MAIN_H
+
 #include <getopt.h>
 
 /**
@@ -46,3 +49,5 @@ Options:
     int mainLoop(const std::vector<std::string> &sourceFiles,
         const std::string &kbFile);
 } // namespace obelisk
+
+#endif