Added pattern preprocessor and #define and #include support

source/lang/preprocessor.cpp

@@ -0,0 +1,120 @@
+#include "lang/preprocessor.hpp"
+
+namespace hex::lang {
+
+    Preprocessor::Preprocessor() {
+
+    }
+
+    std::pair<Result, std::string> Preprocessor::preprocess(const std::string& code, bool applyDefines) {
+        u32 offset = 0;
+
+        if (applyDefines)
+            this->m_defines.clear();
+
+        std::string output;
+        output.reserve(code.length());
+
+        while (offset < code.length()) {
+            if (code[offset] == '#') {
+                offset += 1;
+
+                if (code.substr(offset, 7) == "include") {
+                    offset += 7;
+
+                    while (std::isblank(code[offset]) || std::isspace(code[offset]))
+                        offset += 1;
+
+                    if (code[offset] != '<' && code[offset] != '"')
+                        return { ResultPreprocessingError, "" };
+
+                    char endChar = code[offset];
+                    if (endChar == '<') endChar = '>';
+
+                    offset += 1;
+
+                    std::string includeFile;
+                    while (code[offset] != endChar) {
+                        includeFile += code[offset];
+                        offset += 1;
+
+                        if (offset >= code.length())
+                            return { ResultPreprocessingError, "" };
+                    }
+                    offset += 1;
+
+                    if (includeFile[0] != '/')
+                        includeFile = "include/" + includeFile;
+
+                    FILE *file = fopen(includeFile.c_str(), "r");
+                    if (file == nullptr)
+                        return { ResultPreprocessingError, "" };
+
+                    fseek(file, 0, SEEK_END);
+                    size_t size = ftell(file);
+                    char *buffer = new char[size + 1];
+                    rewind(file);
+
+                    fread(buffer, size, 1, file);
+                    buffer[size] = 0x00;
+
+                    auto [result, preprocessedInclude] = this->preprocess(buffer, false);
+                    if (result.failed())
+                        return { ResultPreprocessingError, "" };
+
+                    output += preprocessedInclude;
+
+                    delete[] buffer;
+
+                    fclose(file);
+                } else if (code.substr(offset, 6) == "define") {
+                    offset += 6;
+
+                    while (std::isblank(code[offset]))
+                        offset += 1;
+
+                    std::string defineName;
+                    while (!std::isblank(code[offset])) {
+                        defineName += code[offset];
+                        offset += 1;
+
+                        if (offset >= code.length() || code[offset] == '\n' || code[offset] == '\r')
+                            return { ResultPreprocessingError, "" };
+                    }
+
+                    while (std::isblank(code[offset]))
+                        offset += 1;
+
+                    std::string replaceValue;
+                    do {
+                        if (offset >= code.length())
+                            return { ResultPreprocessingError, "" };
+
+                        replaceValue += code[offset];
+                        offset += 1;
+                    } while (code[offset] != '\n' && code[offset] != '\r');
+
+                    this->m_defines.emplace(defineName, replaceValue);
+                }
+            }
+
+            output += code[offset];
+            offset += 1;
+        }
+
+        if (applyDefines) {
+            for (const auto &[define, value] : this->m_defines) {
+                s32 index = 0;
+                while((index = output.find(define, index)) != std::string::npos) {
+                    if (index > 0) {
+                        output.replace(index, define.length(), value);
+                        index += value.length();
+                    }
+                }
+            }
+        }
+
+        return { ResultSuccess, output };
+    }
+
+}