On Wed, Dec 9, 2015 at 5:12 PM, <vish...@stanford.edu> wrote:
> sorry ok, I see - it's
> Expr.head
> and
> Expr.args
>
> Man, I really wish Julia had something like python's help(Expr) to see all
> the methods/fields of a class...
>
```
help?> Expr
search: Expr export nextprod expanduser expm exp2 exp expm1 exp10
expand exponent
No documentation found.
Summary:
type Expr <: Any
Fields:
head :: Symbol
args :: Array{Any,1}
typ :: Any
```
>
> On Tuesday, December 8, 2015 at 8:26:35 PM UTC-8, vis...@stanford.edu wrote:
>>
>> Situations where the printed form of an expression (i.e, what you'd type
>> into julia REPL, for example) are equivalent aren't "equal" per julia's
>> standards:
>>
>> Expr(:call, :<, 1, 2) --> :(1 < 2)
>> Meta.show_sexpr(:(1 < 2)) --> (:comparison, 1, :<, 2)
>> Expr(:call, :<, 1, 2) == :(1 < 2) --> FALSE
>>
>> I figure that's expected because the s-expressions behind the scenes
>> aren't accurate.
>> So the workaround is:
>>
>> Expr(:call, :<, 1, 2) == :(<(1,2)) --> TRUE
>>
>> This isn't ideal, but at least there's a way to express the Expr object I
>> want in terms of julia's syntax.
>> Is there another way to make these two semantically equivalent
>> representations actually be equal?
>>
>> Second - a much weirder problem:
>>
>> Meta.show_sexpr(:(symbol.x())) --> (:call, (:., :symbol, (:quote, :x)))
>>
>>
>> Ok, so make an expression:
>>
>> Meta.show_sexpr(Expr(:call, Expr(:., :symbol, Expr(:quote, :x)))) -->
>> (:call, (:., :symbol, (:quote, :x)))
>>
>>
>> Cool. So this time the expression object and the actual julia
>> representation are the exact same.
>>
>> However:
>>
>> Expr(:call, Expr(:., :symbol, Expr(:quote, :x))) == :(symbol.x()) -->
>> FALSE
>>
>>
>> And stragely
>>
>>
>> Meta.show_sexpr(Expr(:call, Expr(:., :symbol, Expr(:quote, :x)))) ==
>> Meta.show_sexpr(:(symbol.x())) --> TRUE
>>
>>
>> What is going on!? And how do I get these expressions to agree?
>>
>>
>> Vishesh
>>
>>
>>
>>
>>
>
