4 ms·

Makes a lot of sense. You have 2 scenarios; 1) old code base in C, rewrite in language du jour. 2) new functionality in either C or spiffy lang 2.0 (SPIFFY).

Makes a lot of sense. You have 2 scenarios; 1) old code base in C, rewrite in language du jour. 2) new functionality in either C or spiffy lang 2.0 (SPIFFY). For scenario 1, all that functionality has to be duplicated, including "defects". Are you sure that the functionality is 100% there or did you miss any use cases? Decision for leaving it. Scenario 2, new widget. Most likely, coding in SPIFFY will be a better choice.

sitkack 9y ago
Run old anomalous traffic on old codebase that can handle the corner cases. Run the new traffic over the safe code that covers 80% of the use cases. Slowly expand the percentage of traffic coverable by the new safe code. The 80 percent case can be written and coded in a small amount of time. In curls example, it is fetching a file over http 1.1 using an encoding, possibly following some redirects. Then post and put requests, then chunked uploads, downloads, then? Need gopher and ftp? Run the old codepath.
- mediocrejoker 9y ago
  If you had a list of all the corner cases from the start, wouldn't it be easy to just cover them in the new code? I thought the point of corner cases was that they introduce bugs because we don't think of them when we design the system.
  - sitkack 9y ago
    If you could infer a spec from the existing code, you have at least a 100M product on your hands.
    - SCHiM 9y ago
      And probably solved the halting problem too ;)
StavrosK 9y ago
Is that because C is a "good language", or just because rewrites are error prone?