gistfile1.txt

~ maglev ✔ maglev-irb -f
irb(main):001:0> b = proc { p 1 }
=> #<Proc>
irb(main):002:0> b.instance_variable_get("@_st_block")
=> #<ExecBlock:0x561a6201 
irb(main):003:0> block = b.instance_variable_get("@_st_block")
=> #<ExecBlock:0x561a6201 
irb(main):004:0> block.class
=> ExecBlock
irb(main):005:0> block.class.primitive '_sourceString', '_sourceString'
=> ExecBlock
irb(main):006:0> block._sourceString
=> "\"This is source for a block.  \" \n ^  { p 1 }"