Add pawn, knight, and king attack move caches

makefile

@@ -0,0 +1,46 @@
+# Makefile at project root
+
+CC       := gcc
+CFLAGS   := -O3 -fPIC -Wall -Wextra
+LDFLAGS  := -shared
+
+SRCDIR   := engine/src
+INCDIR   := engine/include
+BUILDDIR := build
+LIBNAME  := libchess
+
+UNAME_S  := $(shell uname -s)
+ifeq ($(UNAME_S),Darwin)
+  SOEXT := dylib
+else
+  SOEXT := so
+endif
+
+SRC := $(wildcard $(SRCDIR)/*.c)
+OBJ := $(patsubst $(SRCDIR)/%.c,$(BUILDDIR)/%.o,$(SRC))
+LIB := $(BUILDDIR)/$(LIBNAME).$(SOEXT)
+
+.PHONY: all clean clean-pycache test
+
+all: $(LIB)
+
+$(BUILDDIR):
+	@mkdir -p $(BUILDDIR)
+
+# compile each .c into build/*.o
+$(BUILDDIR)/%.o: $(SRCDIR)/%.c | $(BUILDDIR)
+	$(CC) $(CFLAGS) -I$(INCDIR) -c $< -o $@
+
+# link shared library
+$(LIB): $(OBJ)
+	$(CC) $(LDFLAGS) -o $@ $^
+
+clean:
+	@echo "Cleaning Python caches..."
+	@find . -type d -name "__pycache__"  -exec rm -rf {} +
+	@find . -type d -name ".pytest_cache" -exec rm -rf {} +
+	@find . -type f \( -name "*.pyc" -o -name "*.pyo" \) -delete
+
+# run Python unit tests
+test: all
+	python3 -m unittest -v && $(MAKE) clean