This is a bootstrap of Parrot's nqp in nqp
Perl Parrot
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NQP - Not Quite Perl (6)

This is "Not Quite Perl" -- a compiler for quickly generating PIR routines from Perl6-like code. The key feature of NQP is that it's designed to be a very small compiler (as compared with, say, perl6 or Rakudo) and is focused on being a high-level way to create transformers for Parrot (especially hll compilers). In addition, unlike Rakudo, NQP attempts to restrict itself to generating code that can run in Parrot without the existence of any NQP-specific runtime libraries.

One way that NQP aims to be a lighter version of Perl 6 is by avoiding syntactic sugar and "dwimminess" that isn't needed for the types of routines that are written. Sometimes this makes coding a bit more work, but it also lowers the learning curve somewhat.

Things that NQP has (or should have)

This list isn't exhaustive; for now it's intended to identify the language constructs that we explicitly know will be supported

  • scalars
  • binding
  • lexical 'my', package 'our'
  • method calls (including named, optional, and slurpy arguments)
  • subroutine calls (including named, optional, and slurpy arguments)
  • method definitions
  • subroutine definitions
  • '...' # string constants
  • "..." # string value with escapes (non-interpolating)
  • postcircumfix:<[ ]> # array subscript
  • postcircumfix:<{ }> # hash subscript
  • postcircumfix:«< >» # constant hash subscript
  • $<...> # constant hash subscript of $/
  • $(...) # scalar context
  • prefix:~ # string context
  • prefix:+ # numeric context
  • say(), print() # output
  • if/unless # conditional
  • for # iterative loop
  • PIR q<>, PIR q:to:<END> # inline PIR

Things that aren't in NQP

There are a large number of Perl 6 constructs and idioms that aren't supported or expected to be supported in NQP. This is by design -- the point of NQP is to provide a lightweight HLL for generating PIR subroutines while adhering to a Perl 6 syntax.

Some items not planned for NQP:

  • string interpolation
  • listops
  • quoted lists
  • array and hash slices

Of course, if we later decide that some item is vitally important for NQP programs, we can add it -- but for now the point is to maintain a minimal set of constructs.