Put extensions in Lua module instead of sneaking them in environment

Note that neither .cache/config.lua nor .cache/site-tree.json get
updated when EXTENSIONS changes.  This could be hacked as follows:

    config = EXTENSIONS="$(EXTENSIONS)"

    ifneq "$(shell test -f $(config_token) && cat $(config_token))"     \
    "$(shell ./generate-config-token.py $(config))"

    .PHONY: $(lua_config) $(site_tree) $(config_token)
    endif

Plus a recipe for config_token, and some dependencies on it.

1 files changed, 34 insertions, 0 deletions

diff --git a/repo/www/generate-lua-config.py b/repo/www/generate-lua-config.py
new file mode 100755
index 0000000..0a00443
--- /dev/null
+++ b/repo/www/generate-lua-config.py
@@ -0,0 +1,34 @@
+#!/usr/bin/env python3
+
+from sys import argv
+
+
+TEMPLATE = '''\
+local config = {{}}
+
+config.EXTENSIONS = {{ {EXTENSIONS} }}
+
+return config
+'''
+
+
+def _quote(s):
+    return f"'{s}'"
+
+
+def main(arguments):
+    pairs = (arg.split('=') for arg in arguments)
+
+    formatters = {
+        'EXTENSIONS': lambda v: ', '.join(map(_quote, v.split()))
+    }
+
+    parameters = {
+        key: formatters[key](value) for (key, value) in pairs
+    }
+
+    print(TEMPLATE.format_map(parameters), end='')
+
+
+if __name__ == '__main__':
+    main(argv[1:])