tkelman / helpme.jl

Provides the @helpme macro, a machine-learning based suggestion engine for your troubled code.

Helpme

Frustrating error messages getting you down? Wrap the code giving you problems in a call to the @helpme macro like so:

julia> Pkg.add("Helpme")
julia> using Helpme
julia> @helpme begin
       merge(["foo"=>"Hello World!"], ["bar"=>1337])
       end
INFO: Julia attempts to choose the proper type for Dicts when [...] is used, and functions like merge(collection, others...) can be fussy when types don't match up. To force Julia to assign the type Dict{Any,Any}, use {...}. More info at <http://bit.ly/1nUDhyc>.

Helpme will attempt to find a suggestion based on the exception raised and the code passed. If one is found, it will print a friendly message to INFO.

Usage

When @helpme is passed an expression, it executes it, catching any errors raised. It then breaks these errors and the expression down into a list of features. Finally, it searches through an in-memory database with similar sets of features to determine which suggestions to provide.

It's important to know a few tips to get the most out of this package.

Expression Size

Expressions that are very large can confuse the feature-search. The best way to use @helpme is to pass it a smallish expression that raises the error you are getting.

Syntax Errors

If you are trying to figure out a syntax error, @helpme can't help normally because Julia will raise the error before the macro has the chance to examine it. To work around this, wrap your troublesome code up like so:

julia> @helpme eval(parse("a .=== b"))

Note that there are serious issues with using eval: it always uses global scope. Take care with this workaround.

Retraining

Helpme's database needs to be trained when it first loads (which only takes a few seconds). Furthermore, because each verson of Julia may have different syntax trees and/or error messages, each requires its own database file.

I'll attempt to include an appropriate pre-trained database for each Julia version in Helpme/src/database.VERSION.jl so that training only needs to be done on my machine.

However, if you want to retrain your database manually for any reason, delete Helpme/src/database.VERSION.jl, open the Julia REPL, and run julia> using Helpme.