Merge pull request #533 from chriselrod/optimizeisequal

optimize `isequal`

src/types.jl

@@ -189,14 +189,25 @@ Base.isequal(::Symbolic, x) = false
 Base.isequal(x, ::Symbolic) = false
 Base.isequal(::Symbolic, ::Symbolic) = false
 coeff_isequal(a, b) = isequal(a, b) || ((a isa AbstractFloat || b isa AbstractFloat) && (a==b))
+function _allarequal(xs, ys)::Bool
+    N = length(xs)
+    length(ys) == N || return false
+    for n = 1:N
+        isequal(xs[n], ys[n]) || return false
+    end
+    return true
+end
+
 function Base.isequal(a::BasicSymbolic{T}, b::BasicSymbolic{S}) where {T,S}
     a === b && return true
 
     E = exprtype(a)
     E === exprtype(b) || return false
 
     T === S || return false
-
+    return _isequal(a, b, E)::Bool
+end
+function _isequal(a, b, E)
     if E === SYM
         nameof(a) === nameof(b)
     elseif E === ADD || E === MUL
@@ -208,9 +219,7 @@ function Base.isequal(a::BasicSymbolic{T}, b::BasicSymbolic{S}) where {T,S}
     elseif E === TERM
         a1 = arguments(a)
         a2 = arguments(b)
-        isequal(operation(a), operation(b)) &&
-            length(a1) == length(a2) &&
-            all(isequal(l, r) for (l, r) in zip(a1, a2))
+        isequal(operation(a), operation(b)) && _allarequal(a1, a2)
     else
         error_on_type()
     end
@@ -223,13 +232,12 @@ Base.nameof(s::BasicSymbolic) = issym(s) ? s.name : error("None Sym BasicSymboli
 
 ## This is much faster than hash of an array of Any
 hashvec(xs, z) = foldr(hash, xs, init=z)
-
 const SYM_SALT = 0x4de7d7c66d41da43 % UInt
 const ADD_SALT = 0xaddaddaddaddadda % UInt
 const SUB_SALT = 0xaaaaaaaaaaaaaaaa % UInt
 const DIV_SALT = 0x334b218e73bbba53 % UInt
 const POW_SALT = 0x2b55b97a6efb080c % UInt
-function Base.hash(s::BasicSymbolic, salt::UInt)
+function Base.hash(s::BasicSymbolic, salt::UInt)::UInt
     E = exprtype(s)
     if E === SYM
         hash(nameof(s), salt ⊻ SYM_SALT)