+/// numberexpr ::= number
+static std::unique_ptr<ExprAST> ParseNumberExpr() {
+ auto Result = helper::make_unique<NumberExprAST>(NumVal);
+ getNextToken(); // consume the number
+ return std::move(Result);
+}
+
+/// parenexpr ::= '(' expression ')'
+static std::unique_ptr<ExprAST> ParseParenExpr() {
+ getNextToken(); // eat (.
+ auto V = ParseExpression();
+ if (!V)
+ return nullptr;
+
+ if (CurTok != ')')
+ return Error("expected ')'");
+ getNextToken(); // eat ).
+ return V;
+}