Remove type parameter from Operator

docs/src/manual/interface.md

@@ -41,7 +41,6 @@ These functions may be necessary or useful for implementing the operator interfa
 ### Printing
 
 ```@docs
-Interface.name
 Interface.is_root
 Interface.parenthesize
 Interface.print_proposition

docs/src/tutorials/custom_operators.md

@@ -37,10 +37,6 @@ ERROR: InterfaceError: implement `symbol` for `Operator{:truth}()`
 
 If a required method is not implemented, a runtime error will display the function and operator that a method must be implemented for. The error says to implement [`symbol`](@ref Interface.symbol). This function is used to print an operator.
 
-```@setup 1
-const truth = Operator{:truth}()
-```
-
 ```@repl 1
 symbol(::typeof(truth)) = "truth";
 truth
@@ -49,10 +45,6 @@ truth()
 
 The error says to implement [`Evaluation`](). This function is used to specify whether an operator lazily or eagerly evaluates its arguments.
 
-```@setup 1
-Evaluation(::typeof(truth)) = Lazy
-```
-
 ```
 julia> Evaluation(::typeof(truth)) = Lazy;
 

src/PAndQ.jl

@@ -7,12 +7,6 @@ using PrecompileTools: @compile_workload
     union_typeof(xs)
 
 Equivalent to `Union{map(typeof, xs)...}`.
-
-# Examples
-```jldoctest
-julia> PAndQ.union_typeof((⊤, ¬, ∧))
-Union{PAndQ.Interface.Operator{:tautology}, PAndQ.Interface.Operator{:not}, PAndQ.Interface.Operator{:and}}
-```
 """
 union_typeof(xs) = Union{map(typeof, xs)...}
 
@@ -30,7 +24,7 @@ import .Interface:
     Associativity,
     arity, dual, evaluate, initial_value,
     is_associative, is_commutative, print_expression, print_proposition, symbol
-using .Interface: left, Operator, right, name, parenthesize
+using .Interface: left, Operator, right, parenthesize
 export Interface
 
 include("operators.jl")

src/interface.jl

@@ -8,7 +8,7 @@ using PAndQ
 export
     Associativity, left, Operator, right,
     arity, dual, evaluate, initial_value, is_associative, is_commutative,
-    is_root, name, parenthesize, print_expression, print_proposition, symbol
+    is_root, parenthesize, print_expression, print_proposition, symbol
 
 """
     Operator{O}
@@ -22,7 +22,9 @@ If possible, an operator should be defined as
 
 This method is required to instantiate an operator.
 """
-struct Operator{O} end
+struct Operator
+    name::Symbol
+end
 
 # Internals
 
@@ -68,10 +70,10 @@ This method is required to [`normalize`](@ref) a proposition containing the give
 
 # Examples
 ```jldoctest
-julia> @atomize Interface.evaluate(:not, [¬p])
+julia> @atomize Interface.evaluate(¬, [¬p])
 p
 
-julia> @atomize Interface.evaluate(:imply, [p, q])
+julia> @atomize Interface.evaluate(→, [p, q])
 ¬p ∨ q
 ```
 """
@@ -134,17 +136,17 @@ for a proposition `p` containing the given operator.
 
 # Examples
 ```jldoctest
-julia> @atomize Interface.print_expression(stdout, Interface.name(⊤), [])
+julia> @atomize Interface.print_expression(stdout, ⊤, [])
 ⊤
 
-julia> @atomize Interface.print_expression(stdout, Interface.name(¬), [p])
+julia> @atomize Interface.print_expression(stdout, ¬, [p])
 ¬p
 
-julia> @atomize Interface.print_expression(stdout, Interface.name(∧), [p, q])
+julia> @atomize Interface.print_expression(stdout, ∧, [p, q])
 p ∧ q
 ```
 """
-@interface print_expression io o ps
+function print_expression end
 
 """
     symbol(ℴ::Operator)
@@ -160,40 +162,21 @@ See also [`show`](@ref).
 # Examples
 ```jldoctest
 julia> Interface.symbol(⊤)
-"⊤"
+:⊤
 
 julia> Interface.symbol(¬)
-"¬"
+:¬
 
 julia> Interface.symbol(∧)
-"∧"
+:∧
 ```
 """
-@interface symbol o
+function symbol end
 
 # Utilities
 
 ## Printing
 
-"""
-    name(::Operator{O})
-
-Return `O`, the name of the [`Operator`](@ref Interface.Operator).
-
-# Examples
-```jldoctest
-julia> Interface.name(⊤)
-:tautology
-
-julia> Interface.name(¬)
-:not
-
-julia> Interface.name(∧)
-:and
-```
-"""
-name(::Operator{O}) where O = O
-
 """
     is_root(io)
 

src/operators.jl

@@ -19,7 +19,7 @@ julia> print_table(⊤)
 └───┘
 ```
 """
-const tautology = ⊤ = Operator{:tautology}()
+const tautology = ⊤ = Operator(:tautology)
 
 """
     contradiction()
@@ -39,7 +39,7 @@ julia> print_table(⊥)
 └───┘
 ```
 """
-const contradiction = ⊥ = Operator{:contradiction}()
+const contradiction = ⊥ = Operator(:contradiction)
 
 # Unary Operators
 
@@ -60,7 +60,7 @@ julia> @atomize print_table(𝒾(p))
 └───┘
 ```
 """
-const identical = 𝒾 = Operator{:identical}()
+const identical = 𝒾 = Operator(:identical)
 
 """
     not(p)
@@ -81,7 +81,7 @@ julia> @atomize print_table(¬p)
 └───┴────┘
 ```
 """
-const not = ¬ = Operator{:not}()
+const not = ¬ = Operator(:not)
 
 # Binary Operators
 
@@ -107,7 +107,7 @@ julia> @atomize print_table(p ∧ q)
 └───┴───┴───────┘
 ```
 """
-const and = ∧ = Operator{:and}()
+const and = ∧ = Operator(:and)
 
 """
     or(p, q)
@@ -131,7 +131,7 @@ julia> @atomize print_table(p ∨ q)
 └───┴───┴───────┘
 ```
 """
-const or = ∨ = Operator{:or}()
+const or = ∨ = Operator(:or)
 
 """
     imply(p, q)
@@ -155,7 +155,7 @@ julia> @atomize print_table(p → q)
 └───┴───┴───────┘
 ```
 """
-const imply = → = Operator{:imply}()
+const imply = → = Operator(:imply)
 
 """
     exclusive_or(p, q)
@@ -179,7 +179,7 @@ julia> @atomize print_table(p ↮ q)
 └───┴───┴───────┘
 ```
 """
-const exclusive_or = ↮ = Operator{:exclusive_or}()
+const exclusive_or = ↮ = Operator(:exclusive_or)
 
 """
     converse_imply(p, q)
@@ -203,7 +203,7 @@ julia> @atomize print_table(p ← q)
 └───┴───┴───────┘
 ```
 """
-const converse_imply = ← = Operator{:converse_imply}()
+const converse_imply = ← = Operator(:converse_imply)
 
 """
     not_and(p, q)
@@ -227,7 +227,7 @@ julia> @atomize print_table(p ↑ q)
 └───┴───┴───────┘
 ```
 """
-const not_and = ↑ = Operator{:not_and}()
+const not_and = ↑ = Operator(:not_and)
 
 """
     not_or(p, q)
@@ -251,7 +251,7 @@ julia> @atomize print_table(p ↓ q)
 └───┴───┴───────┘
 ```
 """
-const not_or = ↓ = Operator{:not_or}()
+const not_or = ↓ = Operator(:not_or)
 
 """
     not_exclusive_or(p, q)
@@ -276,7 +276,7 @@ julia> @atomize print_table(p ↔ q)
 └───┴───┴───────┘
 ```
 """
-const not_exclusive_or = ↔ = Operator{:not_exclusive_or}()
+const not_exclusive_or = ↔ = Operator(:not_exclusive_or)
 
 """
     not_imply(p, q)
@@ -300,7 +300,7 @@ julia> @atomize print_table(p ↛ q)
 └───┴───┴───────┘
 ```
 """
-const not_imply = ↛ = Operator{:not_imply}()
+const not_imply = ↛ = Operator(:not_imply)
 
 """
     not_converse_imply(p, q)
@@ -324,7 +324,7 @@ julia> @atomize print_table(p ↚ q)
 └───┴───┴───────┘
 ```
 """
-const not_converse_imply = ↚ = Operator{:not_converse_imply}()
+const not_converse_imply = ↚ = Operator(:not_converse_imply)
 
 # Nary Operators
 
@@ -347,7 +347,7 @@ julia> @atomize ⋀(p, q, r, s)
 p ∧ q ∧ r ∧ s
 ```
 """
-const conjunction = ⋀ = Operator{:conjunction}()
+const conjunction = ⋀ = Operator(:conjunction)
 
 """
     disjunction(ps...)
@@ -368,7 +368,7 @@ julia> @atomize ⋁(p, q, r, s)
 p ∨ q ∨ r ∨ s
 ```
 """
-const disjunction = ⋁ = Operator{:disjunction}()
+const disjunction = ⋁ = Operator(:disjunction)
 
 # Utilities
 
@@ -379,7 +379,7 @@ ___fold(mapfold, f, o, xs, initial_value) =
     isempty(xs) ? AbstractSyntaxTree(initial_value) : mapfold(f, o, xs)
 
 __fold(f, o, xs) = g -> (args...) -> ___fold(
-    ____fold(associativities[name(o)]), x -> f(g)(args..., x),
+    ____fold(associativities[o]), x -> f(g)(args..., x),
 o, xs, initial_value(o))
 
 _fold() = identity

src/printing.jl

@@ -352,7 +352,7 @@ end
 """
     show(::IO, ::Operator)
 """
-show(io::IO, o::Operator) = print(io, name(o))
+show(io::IO, o::Operator) = print(io, o.name)
 
 """
     show(::IO, p)