metaprogramming - Dealing with end keyword in macros for array indices -


suppose have array of composite type follows:

type mytype a::int b::float end  myarray=mytype[]

for obvious reasons, able use simple indexing access fields of composite types follows:

avals=myarray[1:3].a

the following macro can accomplish type of indexing, long have numeric iterable array:

macro getarray(exp)         iter=eval(exp.args[1].args[2]) exp.args[1].args[2]=:i; :[$(esc(exp)) $(esc(:i)) in $iter] end

how can write similar macro capable of dealing array indices end keyword, i.e.:

avals=@getarray myarray[1:end].a

the following macro solves not indexing problem sets correct output type:

macro getarray(exp)     quote         ftype=typeof($(esc(exp.args[1]))[1].($(esc(exp.args[2]))));         ftype[item.($(exp.args[2])) item in $(esc(exp.args[1]))]     end end

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