[builtins/dict] add => values() method

[Melkor333]

C++ probably fails because I don't wrap the elements in a value.X but we'll see :)

[Melkor333]

btw the X is already missing in the doc/ref/toc-ysh.md

[andychu]

Great, thank you!

How about filling in a one line description for keys() and values() in doc/ref/chap-type-method.md ?

And perhaps 2 examples like the ones in start() end() etc.

I've been doing that lately, we are slowly creeping up :-)

[andychu]

should be called values or v or vals :-)

[andychu]

reminder :)

Oh also I think it should just be

vals = dictionary.values()

No need for list comprehension

In the keys() case we need the list comprehension, because we have to add the value.Str() wrapper

[Melkor333]

I hated the emptiness of that page so I added more examples…

Used = for the value() to show that it's not strictly strings (as it is with keys())

[andychu]

Thanks for adding the documentation! much appreciated

[andychu]

I think we want to encourage a style of no space for ->, but spaces for =>` to make it look more different?

call fruits->append('orange')

vs.

var v = d => values() => reversed()

Because => can be chained and -> can't. -> generally has no return value

What do you think?

[andychu]

reminder :)

Oh also I think it should just be

vals = dictionary.values()

No need for list comprehension

In the keys() case we need the list comprehension, because we have to add the value.Str() wrapper

[andychu]

Oh just to clarify the types a bit, there are extra "wrappers" for YSH level vs. "mycpp" level:

Here's the type of a mycpp str:

s = 'foo'  # type: str

and mycpp dict:

d = {'foo': 42}   # type:  Dict[str, int]  

From core/value.asdl, here's are YSH wrappers

ysh_str = value.Str('foo')  # type: value.Str

And then a mycpp Dict with a value.Str:

var mycpp_dict = {'key': value.Str('foo')}  # type: Dict[str, value_t]

And then a YSH dict!

var ysh_dict = value.Dict(mycpp_dict)  # type: value.Dict

So yeah these extra wrappers take a bit of getting used to!

[Melkor333]

Thanks for your patience with me!
I hope the styling is now a bit better :)

[andychu]

Thank you! I'm going to put this on #help-wanted as another great example