BUG in new parenthesis code

[EasyArray]

# The original rules: ",_a=_a" just passes along the assignment
rule TN  ⟦α⟧          = lex[α]        || α ∈ lex
rule NN  ⟦tree[_α β]⟧ = ⟦β,_a=_a⟧     || α != pro
rule FAR ⟦tree[γ β]⟧  = ⟦β,_a=_a⟧(⟦γ,_a=_a⟧) || isfun(⟦β,_a=_a⟧) and (⟦γ,_a=_a⟧∈dom(⟦β,_a=_a⟧))
rule FAL ⟦tree[β γ]⟧  = ⟦β,_a=_a⟧(⟦γ,_a=_a⟧) || isfun(⟦β,_a=_a⟧) and (⟦γ,_a=_a⟧∈dom(⟦β,_a=_a⟧))

# A revised PM rule: notice the new presupposition!
rule PM  ⟦tree[β γ]⟧  = [λx : ⟦β,_a=_a⟧(x) is not None and ⟦γ,_a=_a⟧(x) is not None . ⟦β,_a=_a⟧(x) ∧ ⟦γ,_a=_a⟧(x)] || τ(⟦γ,_a=_a⟧)==τ(⟦β,_a=_a⟧)==⟨e,t⟩

# New PA and TP rules
rule PA  ⟦tree[_CP β γ]⟧ = [λx : ⟦γ,_a=x⟧ is not None. ⟦γ,_a=x⟧]
rule TP  ⟦tree[_pro β]⟧  = _a

lex raining = 1
lex smokes = [λx . smokesʼ(x)]

⟦tree[_CP who [[_pro t] smokes]],True⟧

adds extra parens around the sentence in the output:

[λx∈e: ⟦(tree[tree[_pro t] smokes]),_a=x⟧ is not None. ⟦(tree[tree[_pro t] smokes]),_a=x⟧]

[EasyArray]

The above is not a huge deal, since (tree[...]) evaluates the same as just tree[...]. However, here is a worse problem:

lex no = [λp . [λq . ext(λy . p(y) & q(y)) == {}]]
⟦no⟧

evaluates to

[λp∈e.[λq∈e. ext[λy∈e. p(y) & q(y)] == {}]]

Notice the lack of parentheses after ext.

[EasyArray]

Actually, even that is not so bad, because I forgot the [] around the lambda function!

[havijw]

Discussion from email

There are no major problems here, but there are some cases where parentheses are being added when they aren't needed.

• At the level where this parenthesis logic is calculated, double brackets should count as delimiters, but they are not in Token.delims, so (among other issues) ⟦foo⟧ for instance would not count as a Span.
  • A hasDelims function that takes into account double brackets should be able to solve this.
• Things that look like f(x) (also including tree[...]) should count as a single item.
  • Logic for detecting something like this already exists with peek in Span.update:
    

    phosphorus/phosphorus/parse.py

    Lines 142 to 144 in eccfe10

    	if peek is not None:
    	DEBUGGING and mylog(f"Next item: {peek}::{type(peek)}")
    	if isinstance(peek, Span) and peek[0].string == "(":

• Spaces are currently being put inside parentheses, when they should be outside. For instance, we get foo( bar) rather than foo (bar), and the latter is clearly preferable.