Invoke propane to parse input file

src/fart.propane

@@ -1,4 +1,5 @@
 tree;
+tree_prefix P;
 
 drop /\s+/;
 

src/fart/Engine.cpp

@@ -1,4 +1,5 @@
 #include <fart/Engine.h>
+#include <fart/Parser.h>
 #include <errno.h>
 #include <stdio.h>
 #include <string.h>
@@ -8,6 +9,11 @@ Engine::Engine(const RenderParams & params)
 {
 }
 
+Engine::~Engine()
+{
+    delete scene;
+}
+
 int Engine::run(string_view input_file, opt<string_view> output_file)
 {
     string output_path;
@@ -49,5 +55,12 @@ int Engine::run(string_view input_file, opt<string_view> output_file)
         return 1;
     }
 
+    delete scene;
+    scene = Parser::load_scene(input_file);
+    if (!scene)
+    {
+        return 1;
+    }
+
     return 0;
 }

src/fart/Engine.h

@@ -2,15 +2,18 @@
 
 #include <fart/ImageWriter.h>
 #include <fart/RenderParams.h>
+#include <fart/Scene.h>
 #include <memory>
 
 class Engine
 {
 public:
     Engine(const RenderParams & params);
+    ~Engine();
     int run(string_view input_file, opt<string_view> output_file);
 
 protected:
     RenderParams params;
     std::unique_ptr<ImageWriter> image_writer;
+    Scene * scene = nullptr;
 };

src/fart/Parser.cpp

@@ -1,5 +1,7 @@
 #include <fart/Parser.h>
+#include <fart/propane.h>
 #include <fart/read_file.h>
+#include <stdio.h>
 
 Scene * Parser::load_scene(const string_view & input_file)
 {
@@ -8,5 +10,59 @@ Scene * Parser::load_scene(const string_view & input_file)
     {
         return nullptr;
     }
-    return nullptr;
+
+    p_context_t * context = p_context_new(input->data(), input->size());
+    size_t result = p_parse(context);
+    p_position_t pos = p_position(context);
+    int fname_len = (int)input_file.size();
+    const char * fname = input_file.data();
+    bool success = false;
+    switch (result)
+    {
+    case P_SUCCESS:
+        success = true;
+        break;
+
+    case P_DECODE_ERROR:
+        fprintf(stderr, "%.*s:%u:%u: error: invalid UTF-8 encoding\n",
+            fname_len, fname, pos.row, pos.col);
+        break;
+
+    case P_UNEXPECTED_INPUT:
+        fprintf(stderr, "%.*s:%u:%u: error: unexpected input\n",
+            fname_len, fname, pos.row, pos.col);
+        break;
+
+    case P_UNEXPECTED_TOKEN:
+    {
+        p_token_t token = p_token(context);
+        if (token == TOKEN___EOF)
+        {
+            fprintf(stderr, "%.*s:%u:%u: error: unexpected end of input\n",
+                fname_len, fname, pos.row, pos.col);
+        }
+        else
+        {
+            fprintf(stderr, "%.*s:%u:%u: error: unexpected token '%s'\n",
+                fname_len, fname, pos.row, pos.col, p_token_names[token]);
+        }
+        break;
+    }
+
+    default:
+        fprintf(stderr, "%.*s:%u:%u: internal error: unknown parser result %zu\n",
+            fname_len, fname, pos.row, pos.col, result);
+        break;
+    }
+
+    if (!success)
+    {
+        p_context_delete(context);
+        return nullptr;
+    }
+
+    /* TODO: populate the Scene from p_result(context). */
+    Scene * scene = new Scene();
+    p_context_delete(context);
+    return scene;
 }

src/fart/Parser.h

@@ -1,6 +1,6 @@
 #pragma once
 
-#include <fart/propane.h>
+#include <fart/Scene.h>
 
 class Parser
 {