Add compare_monomials (#258)

* Add compare_monomials

* Fix format

Author: blegat

src/default_polynomial.jl

@@ -93,19 +93,27 @@ Base.one(p::Polynomial) = one(typeof(p))
 Base.zero(::Type{Polynomial{C,T,A}}) where {C,T,A} = Polynomial{C,T,A}(A())
 Base.zero(t::Polynomial) = zero(typeof(t))
 
+compare_monomials(a, b) = compare(monomial(a), monomial(b))
+
 function join_terms(
     terms1::AbstractArray{<:Term},
     terms2::AbstractArray{<:Term},
 )
-    return Sequences.merge_sorted(terms1, terms2, compare, combine)
+    return Sequences.merge_sorted(terms1, terms2, compare_monomials, combine)
 end
 function join_terms!(
     output::AbstractArray{<:Term},
     terms1::AbstractArray{<:Term},
     terms2::AbstractArray{<:Term},
 )
     resize!(output, length(terms1) + length(terms2))
-    return Sequences.merge_sorted!(output, terms1, terms2, compare, combine)
+    return Sequences.merge_sorted!(
+        output,
+        terms1,
+        terms2,
+        compare_monomials,
+        combine,
+    )
 end
 
 function Base.:(+)(p1::Polynomial, p2::Polynomial)

src/deprecate.jl

@@ -19,8 +19,6 @@
 @deprecate leading_coefficient leading_coefficient
 @deprecate removeleadingterm remove_leading_term
 @deprecate removemonomials remove_monomials
-@deprecate mergesorted merge_sorted
-@deprecate mergesorted! merge_sorted!
 @deprecate coefficienttype coefficient_type
 @deprecate constantterm constant_term
 @deprecate zeroterm zero_term

src/sequences.jl

@@ -8,23 +8,24 @@ function merge_sorted!(
     result,
     v1::AbstractArray,
     v2::AbstractArray,
-    isless,
+    compare,
     combine,
     filter = x -> !iszero(x),
 )
-    i = 1
-    i1 = 1
-    i2 = 1
-    while i1 <= length(v1) && i2 <= length(v2)
+    i = firstindex(result)
+    i1 = firstindex(v1)
+    i2 = firstindex(v2)
+    while i1 <= lastindex(v1) && i2 <= lastindex(v2)
         x1 = v1[i1]
         x2 = v2[i2]
-        if isless(x1, x2)
+        Δ = compare(x1, x2)
+        if Δ < 0
             if filter(x1)
                 result[i] = x1
                 i += 1
             end
             i1 += 1
-        elseif isless(x2, x1)
+        elseif Δ > 0
             if filter(x2)
                 result[i] = x2
                 i += 1
@@ -40,13 +41,13 @@ function merge_sorted!(
             i2 += 1
         end
     end
-    for j in i1:length(v1)
+    for j in i1:lastindex(v1)
         if filter(v1[j])
             result[i] = v1[j]
             i += 1
         end
     end
-    for j in i2:length(v2)
+    for j in i2:lastindex(v2)
         if filter(v2[j])
             result[i] = v2[j]
             i += 1
@@ -59,13 +60,13 @@ end
 function merge_sorted(
     v1::AbstractArray,
     v2::AbstractArray,
-    isless = Base.isless,
+    compare,
     combine = Base.:+,
     filter = x -> !iszero(x),
 )
     T = MA.promote_operation(combine, eltype(v1), eltype(v2))
     result = Vector{T}(undef, length(v1) + length(v2))
-    return merge_sorted!(result, v1, v2, isless, combine, filter)
+    return merge_sorted!(result, v1, v2, compare, combine, filter)
 end
 
 end