1 files changed, 49 insertions, 0 deletions
diff --git a/source/20-codegen-compiler/CodegenDecl.cpp b/source/20-codegen-compiler/CodegenDecl.cpp
new file mode 100644
index 0000000..7cf21ce
--- /dev/null
+++ b/source/20-codegen-compiler/CodegenDecl.cpp
@@ -0,0 +1,49 @@
+#include "CodegenDecl.hpp"
+
+#include <Utils.hpp>
+
+static EnumValuePattern NextPattern(EnumValuePattern val) {
+	return (EnumValuePattern)(val + 1);
+}
+
+EnumValuePattern DeclEnum::CalcPattern() const {
+	if (elements.empty()) return EVP_Continuous;
+
+	auto pattern = EVP_Continuous;
+restart:
+	auto lastVal = elements[0].value;
+	for (size_t i = 1; i < elements.size(); ++i) {
+		auto currVal = elements[i].value;
+		switch (pattern) {
+			case EVP_Continuous: {
+				bool satisfy = lastVal + 1 == currVal;
+				if (!satisfy) {
+					pattern = NextPattern(pattern);
+					goto restart;
+				}
+			} break;
+
+			case EVP_Bits: {
+				bool satisfy = (lastVal << 1) == currVal;
+				if (!satisfy) {
+					pattern = NextPattern(pattern);
+					goto restart;
+				}
+			} break;
+
+			// A random pattern can match anything
+			case EVP_Random:
+			case EVP_COUNT: break;
+		}
+		lastVal = currVal;
+	}
+
+	return pattern;
+}
+
+EnumValuePattern DeclEnum::GetPattern() const {
+	if (pattern == EVP_COUNT) {
+		pattern = CalcPattern();
+	}
+	return pattern;
+}