document arguments to exception constructors

[sjkelly]

in : http://docs.julialang.org/en/latest/manual/control-flow/#built-in-exceptions

julia> ArgumentError()
ERROR: `ArgumentError` has no method matching ArgumentError()

julia> BoundsError()
BoundsError()

julia> DivideError()
DivideError()

julia> DomainError()
DomainError()

julia> EOFError()
EOFError()

julia> ErrorException()
ERROR: `ErrorException` has no method matching ErrorException()

julia> InexactError()
InexactError()

julia> InterruptException()
InterruptException()

julia> KeyError()
ERROR: `KeyError` has no method matching KeyError()

julia> LoadError()
ERROR: `LoadError` has no method matching LoadError()

julia> MemoryError()
MemoryError()

julia> MethodError()
ERROR: `MethodError` has no method matching MethodError()

julia> OverflowError()
OverflowError()

julia> ParseError()
ERROR: `ParseError` has no method matching ParseError()

julia> SystemError()
ERROR: `SystemError` has no method matching SystemError()

julia> TypeError()
ERROR: `TypeError` has no method matching TypeError()

julia> UndefRefError()
UndefRefError()

It looks like these are all being exported in https://github.com/JuliaLang/julia/blob/c7fb8f5be03edd30598ef49f10d175601690f997/base/exports.jl

Am I doing something wrong?

[quinnj]

The no method errors are because some of them take string arguments as the error message to be shown to the user.

[sjkelly]

@quinnj That makes sense. I could either update the docs indicating which ones take strings, or add uninitialized constructors. The former sounds better to me. What do you think?

[quinnj]

Adding docs for how things are currently is always a 'yes' 😄 My guess is these methods weren't given a no-arg constructor on purpose; to make sure an explanation goes along with the exception. See also #4744 and a bunch of other threads linked to from there.

[JeffBezanson]

There are help entries for those exception types, but they're documented as variables instead of functions, so their arguments are not documented. This should be fixed in doc/stdlib/base.rst.