Fixing the Piping/Chaining Issue (Rev 3)

Internals & Design
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27

Update: added type assertions and [experimental] special do statement syntax.

Not my finest work, but it’ll have to do for now:

# experimental `do` statement syntax
open("./input/2.txt") do {
    ::IO # new optional arg type assertion

    # setup
    oppmoves = (rock='A', paper='B', scissors='C')
    mymoves = (rock='X', paper='Y', scissors='Z')
    outcome(oppmove, mymove) = begin
        (oppmove, mymove) ∈ ((:rock, :paper), (:paper, :scissors), (:scissors, :rock)) && return 1
        (oppmove, mymove) ∈ ((:paper, :rock), (:scissors, :paper), (:rock, :scissors)) && return -1
        0
    end

    # process
    read(it, String)
    split(it, "\n")
    map(it) do {
        try 
            oppmove = findfirst(==(it[1]), oppmoves)
            mymove = findfirst(==(it[3]), mymoves)
            score = findfirst(==(it[3]), values(mymoves))
            score += 3 + outcome(oppmove, mymove) * 3
        catch; 0 end
    } end
    sum
} end

(my preference of course, would be for f(arg) do {stuff} not to require an end keyword, but I can’t do that without parser changes.)