From 29deffdce9749aa2e4b99dfa3f542c684a5834fc Mon Sep 17 00:00:00 2001
From: Camden Dixie O'Brien <cdo@wip.sh>
Date: Thu, 24 Oct 2024 13:52:50 +0100
Subject: [PATCH] Implement number evaluation

---
 lib/evaluator.c         |  8 ++++++++
 lib/include/evaluator.h |  8 ++++++++
 scripts/build.sh        |  6 +++++-
 scripts/test.sh         |  1 +
 tests/evaluator_tests.c | 33 +++++++++++++++++++++++++++++++++
 5 files changed, 55 insertions(+), 1 deletion(-)
 create mode 100644 lib/evaluator.c
 create mode 100644 lib/include/evaluator.h
 create mode 100644 tests/evaluator_tests.c

diff --git a/lib/evaluator.c b/lib/evaluator.c
new file mode 100644
index 0000000..a40d6cd
--- /dev/null
+++ b/lib/evaluator.c
@@ -0,0 +1,8 @@
+#include "evaluator.h"
+
+int evaluate(const expression_t *expression)
+{
+	if (expression->is_number)
+		return expression->number;
+	return 0;
+}
diff --git a/lib/include/evaluator.h b/lib/include/evaluator.h
new file mode 100644
index 0000000..e08f9bf
--- /dev/null
+++ b/lib/include/evaluator.h
@@ -0,0 +1,8 @@
+#ifndef EVALUATOR_H
+#define EVALUATOR_H
+
+#include "expression.h"
+
+int evaluate(const expression_t *expression);
+
+#endif
diff --git a/scripts/build.sh b/scripts/build.sh
index 72b388b..83f6da8 100644
--- a/scripts/build.sh
+++ b/scripts/build.sh
@@ -7,12 +7,16 @@ CFLAGS="$CFLAGS -Ilib/include"
 mkdir -p build
 
 # Build library
+clang $CFLAGS -c -o build/evaluator.o lib/evaluator.c
 clang $CFLAGS -c -o build/memory_pool.o lib/memory_pool.c
 clang $CFLAGS -c -o build/reader.o lib/reader.c
-ar -crs build/lib.a build/memory_pool.o build/reader.o
+ar -crs build/lib.a build/evaluator.o build/memory_pool.o build/reader.o
 
 # Build tests
 clang $CFLAGS -Itests -c -o build/testing.o tests/testing.c
+clang $CFLAGS -Itests -c -o build/evaluator_tests.o tests/evaluator_tests.c
+clang $CFLAGS -o build/evaluator_tests \
+	  build/evaluator_tests.o build/lib.a build/testing.o
 clang $CFLAGS -Itests -c -o build/reader_tests.o tests/reader_tests.c
 clang $CFLAGS -o build/reader_tests \
 	  build/reader_tests.o build/lib.a build/testing.o
diff --git a/scripts/test.sh b/scripts/test.sh
index 5723764..c631822 100644
--- a/scripts/test.sh
+++ b/scripts/test.sh
@@ -1,2 +1,3 @@
 cd "$(git rev-parse --show-toplevel)"
+echo ":: Evaluator tests ::" && build/evaluator_tests
 echo ":: Reader tests ::" && build/reader_tests
diff --git a/tests/evaluator_tests.c b/tests/evaluator_tests.c
new file mode 100644
index 0000000..dfc2361
--- /dev/null
+++ b/tests/evaluator_tests.c
@@ -0,0 +1,33 @@
+#include "evaluator.h"
+#include "memory_pool.h"
+#include "testing.h"
+
+static memory_pool_t pool;
+
+static void number_1234_is_evaluated_as_1234(void)
+{
+	init_memory_pool(&pool);
+	expression_t *expression = allocate_expression(&pool);
+	expression->is_number = true;
+	expression->number = 1234;
+	const int result = evaluate(expression);
+	ASSERT_EQUAL(1234, result);
+}
+
+static void number_4321_is_evaluated_as_4321(void)
+{
+	init_memory_pool(&pool);
+	expression_t *expression = allocate_expression(&pool);
+	expression->is_number = true;
+	expression->number = 4321;
+	const int result = evaluate(expression);
+	ASSERT_EQUAL(4321, result);
+}
+
+int main(void)
+{
+	TESTING_BEGIN();
+	RUN_TEST(number_1234_is_evaluated_as_1234);
+	RUN_TEST(number_4321_is_evaluated_as_4321);
+	TESTING_END();
+}