skime should be a fairly feature-complete pure-Python Scheme fallback for Schemepy after that. I’ve moved the source to the Schemepy repository. And now the backend wrapper (yes, pure-Python fallback still need backend wrapper) is also finished and most of the existing test cases have passed on that.
I committed almost nothing to the Thousand Parsec repository this week. That’s because I’m mainly working on skime — a pure-Python VM for Scheme. After one-week hard working, the basic shape of the VM is already there.
Although there are still many work (e.g. the macro system) to do before it can be a really useful VM, I decide to write a simple layer to fit the Schemepy API and run the benchmarks to see whether the time spent on a new fallback is worth.
I came across a very strange error when tweaking the skime compiler. I decided to use the more specific push_0 and push_1 instruction instead of the general push_literal when the literal is 0 and 1 respectively. However, after added this code, several test cases was broken immediately.
After examining the execution of the failing test cases, I found that I got a 0 when expecting a False. And I finally found the problem is that I use if literal == 0 to test whether I got a literal 0. But unfortunately, False == 0 (as well as True == 1) evaluates to True in Python. So there’s the bug.
I’m feeling rather surprised when I found False == 0. Yes, I know we use 0 to represent a false value in C, but I really don’t expect it to be in Python — such a high-level and duck-typing language. However, since it is already there, I have to remember.
其实我也不会写什么“导读”，只是今天在 newsmth 的 FuncProgram 版看到这篇文章的链接，读了一下，有种强烈地想要推荐给别人读一下的冲动。
，而现在变成了这样：
，我倒是不关心两个哪个寓意更深一些，既然各个人的品味不同，我也一定想坚持一下我觉得前者更好看的观点。
I came across a very strange error when tweaking the 
再过几天就要搬家了，离开紫金港，去玉泉。两个室友已经整理好行李回家了，寝室也略显的有些空空荡荡。虽然从小就经常搬家，但是搬家的时候我一般都在外面读书，只是回家以后发现目的地变成了另外一个地方了，自己却没有多少体会过搬家的过程，而且对于我来说，也只是位置变了一下，因为即使搬家，父母也不会轻易丢掉我的任何东西。我是一个倔强的人，你如果想通过某种强制的方式把你的观点加到我身上，必定会造成不愉快，但是父母一直都很尊重我自己的观点，这让我一直觉得是很幸福的。