Add makefile

Makefile

@@ -0,0 +1,32 @@
+# phony trick from https://keleshev.com/my-book-writing-setup/
+.PHONY: phony
+
+install: phony
+ifndef VIRTUAL_ENV
+	$(error install can only be run inside a Python virtual environment)
+endif
+	@echo Installing dependencies...
+	pip install -r requirements-dev.txt
+	pip install -e .
+
+lint: phony lint-flake lint-mypy
+
+lint-flake: phony
+	flake8
+
+lint-flake-pre310: phony
+	# Python <3.10 doesn't support pattern matching.
+	flake8 --extend-exclude tests/test_pattern_matching.py
+
+lint-mypy: phony
+	mypy
+
+test: phony
+	pytest
+
+docs: phony
+	lazydocs \
+		--overview-file README.md \
+		--src-base-url https://github.com/rustedpy/maybe/blob/main/ \
+		./src/maybe
+