4
在10 Things You Didn't Know Ruby Could Do,滑动30,詹姆斯·爱德华·格雷II提到信息显示在ruby --dump在运行时是否可用?
ruby -e 'puts { is_this_a_block }' --dump parsetree
产生
###########################################################
## Do NOT use this node dump for any purpose other than ##
## debug and research. Compatibility is not guaranteed. ##
###########################################################
# @ NODE_SCOPE (line: 1)
# +- nd_tbl: (empty)
# +- nd_args:
# | (null node)
# +- nd_body:
# @ NODE_ITER (line: 1)
# +- nd_iter:
# | @ NODE_FCALL (line: 1)
# | +- nd_mid: :puts
# | +- nd_args:
# | (null node)
# +- nd_body:
# @ NODE_SCOPE (line: 1)
# +- nd_tbl: (empty)
# +- nd_args:
# | (null node)
# +- nd_body:
# @ NODE_VCALL (line: 1)
# +- nd_mid: :is_this_a_block
这里输出在运行时可用的信息?如果是这样,那么这些信息仅代表哪些代码已被写下,或者它是否也具有已完成的任何元编程的结果?