From de7f9efd5403d42139c143fd6664f3b2c313b4c7 Mon Sep 17 00:00:00 2001
From: Aviv Palivoda <palaviv@gmail.com>
Date: Fri, 13 Dec 2019 11:33:19 +0200
Subject: [PATCH] Support expression in f-strings spec

---
 src/compile.rs | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/compile.rs b/src/compile.rs
index 24df923..d02d3d3 100644
--- a/src/compile.rs
+++ b/src/compile.rs
@@ -2108,10 +2108,17 @@ impl<O: OutputStream> Compiler<O> {
                     conversion,
                     spec,
                 } => {
+                    match spec {
+                        Some(spec) => self.compile_string(spec)?,
+                        None => self.emit(Instruction::LoadConst {
+                            value: bytecode::Constant::String {
+                                value: String::new(),
+                            },
+                        }),
+                    };
                     self.compile_expression(value)?;
                     self.emit(Instruction::FormatValue {
                         conversion: conversion.map(compile_conversion_flag),
-                        spec: spec.clone(),
                     });
                 }
             }