new: release utility

release.py

@@ -0,0 +1,47 @@
+#!/usr/bin/env python3
+import subprocess
+import re
+
+# print changelog
+current_tag = subprocess.run(
+    ['git', 'describe', '--tags', '--abbrev=0'], capture_output=True, text=True).stdout.strip()
+if current_tag == "":
+    # os.system("git log HEAD --oneline")
+    interval = 'HEAD'
+else:
+    print("current tag: %s" % current_tag)
+    interval = '%s..HEAD' % current_tag
+
+print("CHANGELOG:\n\n%s\n" % subprocess.run(
+    ['git', 'log', interval, '--oneline'], capture_output=True, text=True).stdout.strip())
+
+version_match_re = r'^version\s*=\s*"([^"]+)"$'
+
+with open('Cargo.toml', 'rt') as fp:
+    manifest = fp.read()
+
+# parse current version and get next from user
+m = re.findall(version_match_re, manifest, re.MULTILINE)
+if len(m) != 1:
+    print("could not parse current version from Cargo.toml")
+    quit()
+
+current_ver = m[0]
+next_ver = input("current version is %s, enter next: " % current_ver)
+
+# generate new manifest
+result = re.sub(version_match_re, 'version = "%s"' %
+                next_ver, manifest, 0, re.MULTILINE)
+with open('Cargo.toml', 'w+t') as fp:
+    fp.write(result)
+
+# commit, push and create new tag
+print("git add Cargo.*")
+print("git commit -m 'releasing version %s'" % next_ver)
+print("git push")
+print("git tag -a v%s -m 'releasing v%s'" % (next_ver, next_ver))
+print("git push origin v%s" % next_ver)
+
+print()
+# publish on crates.io
+print("cargo publish")