Program braces in phi-calculus expression

[maxonfjvipon]

This is a canonical phi-calculus EBNF:

Here we assume that program is a special alpha binding where attribute is Φ.
In order not to write such top level alpha binding explicitly in every expression we decided to replace it with { } brackets.
Current Phi.g4 has bindings rule between { } brackets which seems wrong (because object is not always bindings).

If we replace current rule program: '{' bindings '}' with program: '{' object '}' (to be more canonical) then we get not really pretty phi expression, for example: {[x -> y]}.

I suggest to get rid of { } brackets and write top level alpha binding with Φ explicitly.
@yegor256 WDYT?

[yegor256]

@maxonfjvipon how about program: '{' ( bindings | object ) '}' instead?

[maxonfjvipon]

@yegor256 I'm just trying to figure out what we're trying to replace with { } brackets.
In case: program: Φ -> formation => program: Φ -> [ bindings ] we replace Φ -> []
In case: program: Φ -> dispatch or program: Φ -> application we replace something else, because dispatch or application may contain no low level bindings at all.

I think we should decide what exactly syntax (or semantic) rule we replace with { } brackets.

UPD: Or we should change program rule with something like this:

program: Φ -> formation

[yegor256]

@maxonfjvipon what's wrong with program: Φ -> application? Something like this is valid: { $.int(42) }. It's similar to: Φ -> $.int(42). Dataization of Φ is the execution of a program. Thus, this program will fail, since there is no int in Φ, but syntactically it's correct.

[maxonfjvipon]

@yegor256 here Φ -> $.int(42) => { $.int(42) } brackets { } are replacing Φ ->
But here Φ -> [ x -> Φ.org.eolang.int ] => { x -> Φ.org.eolang.int } brackets { } are replacing Φ -> [].
I think it may confuse some devs who works with our interpretation of phi-calculus expression.

[yegor256]

@maxonfjvipon I agree. Let's make it this way: {[ x -> Φ.int(42) ]}, if they mean Φ -> [ x -> Φ.int(42) ]

[maxonfjvipon]

@yegor256 so we establish that brackets { } are replacing top level alpha binding Φ -> .

[yegor256]

@maxonfjvipon yes