From 3b73978f40c5b198b1769ffc6c67547afe535ec0 Mon Sep 17 00:00:00 2001
From: Luna <git@l4.pm>
Date: Fri, 31 May 2019 23:37:45 -0300
Subject: [PATCH] add make_exprs.py script

---
 scripts/make_exprs.py | 49 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100755 scripts/make_exprs.py

diff --git a/scripts/make_exprs.py b/scripts/make_exprs.py
new file mode 100755
index 0000000..97ed36f
--- /dev/null
+++ b/scripts/make_exprs.py
@@ -0,0 +1,49 @@
+#!/usr/bin/python3.6
+
+from pathlib import Path
+
+EXPR_TYPES = {
+    'Binary': ('left: Expr', 'operator: Token', 'right: Expr'),
+    'Grouping': ('expression: Expr'),
+    'Unary': ('operator: Token', 'right: Expr'),
+
+    # NOTE: when adding new Literals, add new Literal types, instead of just
+    # doing Literal with an 'Object value'. it won't work.
+}
+
+def _gen_expr_decls():
+    res = []
+
+    for expr_type, expr_params in EXPR_TYPES.items():
+        res.append(f'pub const {expr_type} = struct {{')
+
+        for param in expr_params:
+            res.append(f'{param},')
+
+    return '\n'.join(res)
+
+
+def do_base_union(union_name: str):
+    res = [
+        'const Token = @import("token.zig").Token;\n'
+    ]
+
+    res.extend(_gen_expr_decls())
+    res.append(f'pub const {union_name} = union {{')
+
+    for expr_type in EXPR_TYPES:
+        res.append(f'{expr_type}: {expr_type},')
+
+    res.append('}\n')
+
+    return '\n'.join(res)
+
+
+def main():
+    expr_file = Path('./src') / 'expr.zig'
+    expr_file.unlink()
+    expr_file.write_text(do_base_union('Expr'))
+
+
+if __name__ == '__main__':
+    main()