diff --git a/lang/lua-ast.lua b/lang/lua-ast.lua
index 6f4c7a2..db4f79c 100644
--- a/lang/lua-ast.lua
+++ b/lang/lua-ast.lua
@@ -9,6 +9,26 @@ local function ident(name, line)
     return build("Identifier", { name = name, line = line })
 end
 
+local function literal(value, line)
+    return build("Literal", { value = value, line = line })
+end
+
+local function field(obj, name, line)
+    return build("MemberExpression", { object = obj, property = ident(name), computed = false, line = line })
+end
+
+local function logical_binop(op, left, right, line)
+    return build("LogicalExpression", { operator = op, left = left, right = right, line = line })
+end
+
+local function binop(op, left, right, line)
+    return build("BinaryExpression", { operator = op, left = left, right = right, line = line })
+end
+
+local function empty_table(line)
+    return build("Table", { keyvals = { }, line = line })
+end
+
 local function does_multi_return(expr)
     local k = expr.kind
     return k == "CallExpression" or k == "SendExpression" or k == "Vararg"