Possible Bug in Displaying Generator Exprs

General Usage
1 
    [Error showing value of type Expr:
ERROR: type LineNumberNode has no field args
Stacktrace:
 [1] getproperty(::Any, ::Symbol) at ./Base.jl:20
 [2] show_generator(::IOContext{REPL.Terminals.TTYTerminal}, ::Expr, ::Int64) at ./array.jl:0
 [3] show_unquoted(::IOContext{REPL.Terminals.TTYTerminal}, ::Expr, ::Int64, ::Int64) at ./show.jl:1248
 [4] show_block(::IOContext{REPL.Terminals.TTYTerminal}, ::String, ::Array{Any,1}, ::Expr, ::Int64) at ./show.jl:936
 [5] show_block(::IOContext{REPL.Terminals.TTYTerminal}, ::String, ::Expr, ::Int64) at ./show.jl:940
 [6] show_unquoted_quote_expr(::IOContext{REPL.Terminals.TTYTerminal}, ::Any, ::Int64, ::Int64) at ./show.jl:1055
 [7] show at ./show.jl:766 [inlined]
 [8] show(::IOContext{REPL.Terminals.TTYTerminal}, ::MIME{Symbol("text/plain")}, ::Expr) at ./multimedia.jl:47
 [9] display(::REPL.REPLDisplay, ::MIME{Symbol("text/plain")}, ::Any) at /Users/sabae/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.2/REPL/src/REPL.jl:132
 [10] display(::REPL.REPLDisplay, ::Any) at /Users/sabae/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.2/REPL/src/REPL.jl:136
 [11] display(::Any) at ./multimedia.jl:323
 [12] #invokelatest#1 at ./essentials.jl:790 [inlined]
 [13] invokelatest at ./essentials.jl:789 [inlined]
 [14] print_response(::IO, ::Any, ::Bool, ::Bool, ::Any) at /Users/sabae/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.2/REPL/src/REPL.jl:156
 [15] print_response(::REPL.AbstractREPL, ::Any, ::Bool, ::Bool) at /Users/sabae/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.2/REPL/src/REPL.jl:141
 [16] (::getfield(REPL, Symbol("#do_respond#38")){Bool,getfield(REPL, Symbol("##48#57")){REPL.LineEditREPL,REPL.REPLHistoryProvider},REPL.LineEditREPL,REPL.LineEdit.Prompt})(::Any, ::Any, ::Any) at /Users/sabae/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.2/REPL/src/REPL.jl:718
 [17] #invokelatest#1 at ./essentials.jl:790 [inlined]
 [18] invokelatest at ./essentials.jl:789 [inlined]
 [19] run_interface(::REPL.Terminals.TextTerminal, ::REPL.LineEdit.ModalInterface, ::REPL.LineEdit.MIState) at /Users/sabae/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.2/REPL/src/LineEdit.jl:2306
 [20] run_frontend(::REPL.LineEditREPL, ::REPL.REPLBackendRef) at /Users/sabae/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.2/REPL/src/REPL.jl:1038
 [21] run_repl(::REPL.AbstractREPL, ::Any) at /Users/sabae/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.2/REPL/src/REPL.jl:201
 [22] (::getfield(Base, Symbol("##737#739")){Bool,Bool,Bool,Bool})(::Module) at ./client.jl:390
 [23] #invokelatest#1 at ./essentials.jl:790 [inlined]
 [24] invokelatest at ./essentials.jl:789 [inlined]
 [25] run_main_repl(::Bool, ::Bool, ::Bool, ::Bool, ::Bool) at ./client.jl:374
 [26] exec_options(::Base.JLOptions) at ./client.jl:312
 [27] _start() at ./client.jl:464
2

Well - what have you been trying to display?

3 
[(i,j) for i=1:3 for j=1:i if i+j == 4]

with some extra Line info inside…
when I strip the lines before I show it, it works fine…

4

I can’t reproduce the error with just the snippet you provided:

julia> [(i,j) for i in 1:3 for j in 1:i if i+j == 4 ]
2-element Array{Tuple{Int64,Int64},1}:
 (2, 2)
 (3, 1)

julia> versioninfo()
Julia Version 1.2.0
Commit c6da87ff4b (2019-08-20 00:03 UTC)
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: Intel(R) Core(TM) i7-6600U CPU @ 2.60GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-6.0.1 (ORCJIT, skylake)
Environment:
  JULIA_NUM_THREADS = 4

Perhaps there’s some more context needed?

5

don’t worry , I think it was a malformed expression…