1 files changed, 28 insertions, 0 deletions
diff --git a/third_party/rust/jsparagus/jsparagus/main.py b/third_party/rust/jsparagus/jsparagus/main.py
new file mode 100755
index 0000000000..f54827099f
--- /dev/null
+++ b/third_party/rust/jsparagus/jsparagus/main.py
@@ -0,0 +1,28 @@
+#!/usr/bin/env python3
+
+"""jsparagus/main.py - Generate a parser from a pgen grammar.
+
+(This is for testing. pgen will likely go away. Ignore this for now.)
+"""
+
+import sys
+import argparse
+from . import parse_pgen
+from . import gen
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Generate a parser.")
+    parser.add_argument('--target', choices=['python', 'rust'], default='rust',
+                        help="target language to use when printing the parser tables")
+    parser.add_argument('grammar', metavar='FILE', nargs=1,
+                        help=".pgen file containing the grammar")
+    options = parser.parse_args()
+
+    [pgen_filename] = options.grammar
+    grammar = parse_pgen.load_grammar(pgen_filename)
+    gen.generate_parser(sys.stdout, grammar, target=options.target)
+
+
+if __name__ == '__main__':
+    main()