Rename ^ to syms

[pdeffebach]

^() is currently used to refer to a symbol on its own. for example,

df @> transform(x = :b) will make a new column :x which looks like the column :b, while

df @> transform(x = ^(:b)) makes a new column :x and fills it with the symbol :b. There is nothing about ^() that indicates this behavior. I propose renaming it to syms, because it escapes Symbols and has the same number of letters as cols.

[nalimilan]

Doesn't JuliaDBMeta use cols for this? Cc: @piever

[piever]

cols is used to recognize things that evaluate to a symbol, say::

a = :SepalLength
@with iris cols(a)

Whereas ^ is to escape something to be used as a symbol, for example @map iris ^(:a) will return a column full of the symbol :a.

I'm not sure I agree with the proposed renaming. ^ can escape a whole expression and not only a symbol (it basically takes it out of the macro and evaluates it as is), so the name syms is not completely correct. If anything, for consistency I'd be in favor of adding a infix operator version of cols, say @with iris $a, which is in some sense interpolation, in that a is evaluated before replacing symbols with columns.

[nalimilan]

Got it. Yes, $ for cols kind of makes sense. Maybe we could use esc for ^?

(I still kind of wish we treated all names as columns by default, so that we wouldn't need to escape symbols...)

[pdeffebach]

Got it. Yes, $ for cols kind of makes sense. Maybe we could use esc for ^?

This is okay, but cols also "escapes" the input by evaluating what's inside.

a = :x 
@transform(df, newcol = cols(a)

which is the same as

@transform(df, newcol = :x) # the column `:x` in df. 

Basically we have two divergent ways to escape the variable a.

(I still kind of wish we treated all names as columns by default, so that we wouldn't need to escape symbols...)

Don't we do this already? Or do you mean full tidy evaluation?

[nalimilan]

So what's the conclusion here?

[pdeffebach]

It's weird that we have cols instead of col... But we should rename this to syms for consistency.

[pdeffebach]

Closing this, ^() is fine, and now that we use $ intead of cols it doesn't make sense to have syms.