Compiling PHP's Eval() to .NET (peachpie.io)

As someone who began programming with PHP, and who programs professionally in C# now, PeachPIE has always been a fascinating project to me.

Glad to see Roslyn has made PeachPIE even more capable.

We do something very similar at work, but with runtime generated Java code for an in-memory column oriented database. Our data is analyzed before being loaded and we determine the range of numbers necessary to store the data: eg. If we only have bytes incoming, we generate a class that only stores bytes etc. On top of that all our strings are interned in a trie and then represented as ints, also run through above outlined code.

This works because we are mostly interested in equality of strings and other computation with strings (mostly prefix based classific) is done ahead of time.

For debugging we emit our generated code and both eclipse and intellij picked up our generated code without configuration. It's safed us a lot of headaches.

I needed the ability to safely execute formulas in my .NET app. My solution was to write a parser and interpreter. Here it is: https://github.com/Rajeev-K/formula-parser

  (latestquote - previousquote) / previousquote
  iif(isonlineorder, "Online", "Retail")
  FirstName & " " & LastName
  iif(IsNothing(Amount), "Amount missing",  Format(Amount, "c2"))
  "Q" & ((OrderDate.Month - 1) \ 3 + 1)
  MonthName(DatePart(DateInterval.Month, Today), false)
  DateAdd(DateInterval.Day, 1, Today)

These are the kinds of articles that make me never want to come to this site.

> we simply want to emit the debug information of eval() only if we are just debugging the program. Otherwise it’s just an unnecessary performance overhead.

This will not correctly handle the case when the user attaches a debugger after the eval has started, but before all execution artifacts (including callbacks/closures) are finished.