Crystal AST dump

ast_dump.cr

require "compiler/crystal/**"

class Object
  def dump_inspect(io, level)
    io << "  " * level
    to_s(io)
    io << " :: " << self.class
  end
end

macro dump_prop(name)
  io << "  " * (level+1) << {{name.stringify}} << ":\n"
  if v = {{name}}
    if v.is_a?(Array)
      if v.empty?
        io << "  " * (level+2) << "[]"
      end
      v.each_with_index do |e, i|
        io << "  " * (level+2) << "[" << i << "]\n"
        e.dump_inspect(io, level + 2)
      end
    else
      v.dump_inspect(io, level + 2)
    end
  else
    io << "  " * (level+2) << "nil"
  end
  io << '\n'
end

module Crystal
  abstract class ASTNode
    macro def dump_inspect(io, level) : Int32
      io << "  " * level << {{@type.name}} << '\n'

      {% for ivar, i in @type.instance_vars %}
        {% unless {
            "is_expansion": true,
            "has_parenthesis": true,
            "location": true,
            "type": true,
            "dirty": true,
            "uses_with_scope": true,
            "global": true,
            "visited": true,
            "name_column_number": true,
            "name_length": true,
            "doc": true,
          }[ivar.stringify]  %}
        dump_prop @{{ivar}}
        {% end %}
      {% end %}

      0
    end

    def dump_inspect(io)
      dump_inspect(io, 0)
    end
  end
end

def dump(code)
  parser = Crystal::Parser.new(code)
  parser.parse.dump_inspect(STDOUT)
end

main.cr

require "./ast_dump"

dump "[1,2,3].each do |e|
  puts e
end"

With the current crystal this does not link, on osx at least:

crystal build main.cr 
Undefined symbols for architecture x86_64:
  "_LLVMInitializeX86AsmParser", referenced from:
      _*LLVM::init_x86:Void? in LLVM.o
  "_LLVMInitializeX86AsmPrinter", referenced from:
      _*LLVM::init_x86:Void? in LLVM.o
  "_LLVMInitializeX86Target", referenced from:
      _*LLVM::init_x86:Void? in LLVM.o
  "_LLVMInitializeX86TargetInfo", referenced from:
      _*LLVM::init_x86:Void? in LLVM.o
  "_LLVMInitializeX86TargetMC", referenced from:
      _*LLVM::init_x86:Void? in LLVM.o
  "_LLVMLinkInMCJIT", referenced from:
      _*LLVM::init_x86:Void? in LLVM.o
ld: symbol(s) not found for architecture x86_64

what am I doing wrong?

@radiospiel, sorry I've just notice your message. Take a look at crystal-lang/crystal#438 This involves almost the same requirement as building the crystal compiler, so checking if you are able to build a compiler is a good step for using this snippet.

Hello,

I just tried this sample and I have the following error
Syntax error in src/crystal/ast_dump.cr:33: unexpected token: dump_inspect (parentheses are mandatory for macro arguments)

macro def dump_inspect(io, level) : Int32

The error is when I import the ast_dump file (require "./crystal/ast_dump"), which is a copy/paste of the snippet.