or split the string into rows of strings and rows into individual value-keeper strings and put that into a matrix of strings and process the matrix, tracking row and col and checking for "error"
On Thursday, November 3, 2016 at 5:15:06 AM UTC-4, Jeffrey Sarnoff wrote: > > Or, redefine the question :> > > If you are not tied to string processing, reading the test_file as a > string (if it is) and then splitting the string > ```julia > rowstrings = map(String, split(test_file, '\n')) # need the map to > avoid SubString results, if it matters > # then split the rows on ';' and convert to ?Float64 with NaN for error > or ?Nullable Ints > # and put the values in a matrix, processing the matrix you have the > rows and cols > ``` > > > On Thursday, November 3, 2016 at 4:34:53 AM UTC-4, Tamas Papp wrote: >> >> Jeffrey, >> >> Thanks, but my question was about how to have line and column in the >> error message. So I would like to have an error message like this: >> >> ERROR: Failed to parse "error" as type Int64 in column 2, line 3. >> >> My best idea so far: catch the error at each level, and add i and line >> number. But this requires two try-catch-end blocks with rethrow. >> >> Extremely convoluted mess with rethrow here: >> https://gist.github.com/tpapp/6f67ff36a228f47a1792e011d9b0fc13 >> >> It does what I want, but it is ugly. A simpler solution would be >> appreciated. I am sure I am missing something. >> >> Best, >> >> Tamas >> >> On Thu, Nov 03 2016, Jeffrey Sarnoff wrote: >> >> > Tamas, >> > >> > running this >> > >> > >> > >> > typealias AkoString Union{String, SubString{String}} >> > >> > function parsefield{T <: Real, S <: AkoString}(::Type{T}, str::S) >> > result = T(0) >> > try >> > result = parse(T, str) >> > catch ArgumentError >> > errormsg = string("Failed to parse \"",str,"\" as type ", T) >> > throw(ErrorException(errormsg)) >> > end >> > return result >> > end >> > >> > function parserow(schema, strings) >> > # keep i for reporting column, currently not used >> > [parsefield(T, string) for (i, (T, string)) in >> enumerate(zip(schema, >> > strings))] >> > end >> > >> > function parsefile(io, schema) >> > line = 1 >> > while !eof(io) >> > strings = split(chomp(readline(io)), ';') >> > parserow(schema, strings) >> > line += 1 # currently not used, use for error reporting >> > end >> > end >> > >> > test_file = """ >> > 1;2;3 >> > 4;5;6 >> > 7;8;error >> > """ >> > >> > parsefile(IOBuffer(test_file), fill(Int, 3)) >> > >> > >> > >> > >> > by evaluating parsefile(...), results in >> > >> > >> > >> > julia> parsefile(IOBuffer(test_file), fill(Int, 3)) >> > ERROR: Failed to parse "error" as type Int64 >> > in parsefield(::Type{Int64}, ::SubString{String}) at ./REPL[2]:7 >> > in (::##1#2)(::Tuple{Int64,Tuple{DataType,SubString{String}}}) at >> > ./<missing>:0 >> > in collect_to!(::Array{Int64,1}, >> > >> ::Base.Generator{Enumerate{Base.Zip2{Array{DataType,1},Array{SubString{String},1}}},##1#2}, >> >> >> > ::Int64, ::Tuple{Int64,Tuple{Int64,Int64}}) at ./array.jl:340 >> > in >> > >> collect(::Base.Generator{Enumerate{Base.Zip2{Array{DataType,1},Array{SubString{String},1}}},##1#2}) >> >> >> > at ./array.jl:308 >> > in parsefile(::Base.AbstractIOBuffer{Array{UInt8,1}}, >> ::Array{DataType,1}) >> > at ./REPL[4]:5 >> > >> > >> > >> > >> > >> > On Wednesday, November 2, 2016 at 1:01:30 PM UTC-4, Tamas Papp wrote: >> >> >> >> This is a conceptual question. Consider the following (extremely >> >> stylized, but self-contained) code >> >> >> >> parsefield{T <: Real}(::Type{T}, string) = parse(T, string) >> >> >> >> function parserow(schema, strings) >> >> # keep i for reporting column, currently not used >> >> [parsefield(T, string) for (i, (T, string)) in >> enumerate(zip(schema, >> >> strings))] >> >> end >> >> >> >> function parsefile(io, schema) >> >> line = 1 >> >> while !eof(io) >> >> strings = split(chomp(readline(io)), ';') >> >> parserow(schema, strings) >> >> line += 1 # currently not used, use for error reporting >> >> end >> >> end >> >> >> >> test_file = """ >> >> 1;2;3 >> >> 4;5;6 >> >> 7;8;error >> >> """ >> >> >> >> parsefile(IOBuffer(test_file), fill(Int, 3)) >> >> >> >> This will fail with an error message >> >> >> >> ERROR: ArgumentError: invalid base 10 digit 'e' in "error" >> >> in tryparse_internal(::Type{Int64}, ::SubString{String}, ::Int64, >> >> ::Int64, ::Int64 >> >> , ::Bool) at ./parse.jl:88 >> >> in parse(::Type{Int64}, ::SubString{String}) at ./parse.jl:152 >> >> in parsefield(::Type{Int64}, ::SubString{String}) at ./REPL[152]:1 >> >> in (::##5#6)(::Tuple{Int64,Tuple{DataType,SubString{String}}}) at >> >> ./<missing>:0 >> >> in collect_to!(::Array{Int64,1}, >> >> ::Base.Generator{Enumerate{Base.Zip2{Array{DataTy >> >> pe,1},Array{SubString{String},1}}},##5#6}, ::Int64, >> >> ::Tuple{Int64,Tuple{Int64,Int64 >> >> }}) at ./array.jl:340 >> >> in >> >> >> collect(::Base.Generator{Enumerate{Base.Zip2{Array{DataType,1},Array{SubString{ >> >> >> >> >> >> String},1}}},##5#6}) at ./array.jl:308 >> >> in parsefile(::Base.AbstractIOBuffer{Array{UInt8,1}}, >> >> ::Array{DataType,1}) at ./RE >> >> PL[154]:5 >> >> >> >> Instead, I would like to report something like this: >> >> >> >> ERROR: Failed to parse "error" as Int on line 3, column 3. >> >> >> >> What's the idiomatic way of doing this in Julia? My problem is that >> >> parsefield fails without knowing line or column (i in parserow). I >> could >> >> catch and rethrow, constructing an error object gradually. Or I could >> >> pass line and column numbers to parserow and parsefield for error >> >> reporting, but that seems somehow inelegant (I have seen it in code >> >> though). >> >> >> >> Best, >> >> >> >> Tamas >> >> >> >
