Add round (#44)

JuliaMath · Aug 21, 2017 · de39990 · de39990
1 parent df49cfe
commit de39990
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Showing 2 changed files with 25 additions and 2 deletions.
diff --git a/src/DecFP.jl b/src/DecFP.jl
@@ -184,6 +184,8 @@ for w in (32,64,128)
  Base.trunc(::Type{$Ti′}, x::$BID) = xchk(ccall(($(bidsym(w,"to_",lowercase(i′),"_xint")), libbid), $Ti′, ($BID,), x), InexactError, INVALID | OVERFLOW)
  Base.floor(::Type{$Ti′}, x::$BID) = xchk(ccall(($(bidsym(w,"to_",lowercase(i′),"_xfloor")), libbid), $Ti′, ($BID,), x), InexactError, INVALID | OVERFLOW)
  Base.ceil(::Type{$Ti′}, x::$BID) = xchk(ccall(($(bidsym(w,"to_",lowercase(i′),"_xceil")), libbid), $Ti′, ($BID,), x), InexactError, INVALID | OVERFLOW)
+ Base.round(::Type{$Ti′}, x::$BID) = xchk(ccall(($(bidsym(w,"to_",lowercase(i′),"_xrnint")), libbid), $Ti′, ($BID,), x), InexactError, INVALID | OVERFLOW)
+ Base.round(::Type{$Ti′}, x::$BID, ::RoundingMode{:NearestTiesAway}) = xchk(ccall(($(bidsym(w,"to_",lowercase(i′),"_xrninta")), libbid), $Ti′, ($BID,), x), InexactError, INVALID | OVERFLOW)
  Base.convert(::Type{$Ti′}, x::$BID) = xchk(ccall(($(bidsym(w,"to_",lowercase(i′),"_xfloor")), libbid), $Ti′, ($BID,), x), InexactError)
  end
  end
@@ -197,8 +199,20 @@ end # widths w
 Base.trunc(::Type{Integer}, x::DecimalFloatingPoint) = trunc(Int, x)
 Base.floor(::Type{Integer}, x::DecimalFloatingPoint) = floor(Int, x)
 Base.ceil(::Type{Integer}, x::DecimalFloatingPoint) = ceil(Int, x)
+Base.round(::Type{Integer}, x::DecimalFloatingPoint) = round(Int, x)
+Base.round(::Type{Integer}, x::DecimalFloatingPoint, ::RoundingMode{:NearestTiesAway}) = round(Int, x, RoundNearestTiesAway)
 Base.convert(::Type{Integer}, x::DecimalFloatingPoint) = convert(Int, x)
 
+Base.round{T<:Integer}(::Type{T}, x::DecimalFloatingPoint, ::RoundingMode{:Nearest}) = round(T, x)
+function Base.round{T<:Integer}(::Type{T}, x::DecimalFloatingPoint, ::RoundingMode{:NearestTiesUp})
+ y = floor(T, x)
+ ifelse(x==y, y, copysign(floor(T, 2*x-y), x))
+end
+Base.round{T<:Integer}(::Type{T}, x::DecimalFloatingPoint, ::RoundingMode{:ToZero}) = trunc(T, x)
+Base.round{T<:Integer}(::Type{T}, x::DecimalFloatingPoint, ::RoundingMode{:FromZero}) = (x>=0 ? ceil(T, x) : floor(T, x))
+Base.round{T<:Integer}(::Type{T}, x::DecimalFloatingPoint, ::RoundingMode{:Up}) = ceil(T, x)
+Base.round{T<:Integer}(::Type{T}, x::DecimalFloatingPoint, ::RoundingMode{:Down}) = floor(T, x)
+
 # the complex-sqrt function in base doesn't work for use, because it requires base-2 ldexp
 function Base.sqrt{T<:DecimalFloatingPoint}(z::Complex{T})
  x, y = reim(z)

diff --git a/test/runtests.jl b/test/runtests.jl
@@ -85,7 +85,11 @@ for T in (Dec32, Dec64, Dec128)
  if Ti != Integer
  @test parse(T, "17") == T(Ti(17)) == Ti(17) == Ti(T(17))
  end
- @test trunc(Ti, T(4.5)) == floor(Ti, T(4.5)) == 4 == ceil(Ti, T(4.5)) - 1
+ @test trunc(Ti, T(2.7)) === floor(Ti, T(2.7)) === round(Ti, T(2.7), RoundDown) === round(Ti, T(2.7), RoundToZero) === Ti(2)
+ @test ceil(Ti, T(2.3)) === round(Ti, T(2.3), RoundUp) === round(Ti, T(2.3), RoundFromZero) === Ti(3)
+ @test round(Ti, T(1.5)) === round(Ti, T(2.5)) === round(Ti, T(1.5), RoundNearest) === round(Ti, T(2.5), RoundNearest) === Ti(2)
+ @test round(Ti, T(2.5), RoundNearestTiesAway) === round(Ti, T(3.3), RoundNearestTiesAway) === Ti(3)
+ @test round(Ti, T(2.5), RoundNearestTiesUp) === round(Ti, T(3.3), RoundNearestTiesUp) === Ti(3)
  @test_throws InexactError convert(Ti, xd)
  @test_throws InexactError trunc(Ti, realmax(T))
  @test_throws InexactError floor(Ti, realmax(T))
@@ -94,7 +98,12 @@ for T in (Dec32, Dec64, Dec128)
  @test parse(T, "-17") == T(Ti(-17)) == Ti(-17) == Ti(T(-17))
  end
  if Ti <: Signed || Ti === Integer
- @test floor(Ti, T(-4.5)) == -5 == trunc(Ti, T(-4.5)) - 1 == ceil(Ti, T(-4.5)) - 1
+ @test trunc(Ti, T(-2.7)) === round(Ti, T(-2.7), RoundToZero) === Ti(-2)
+ @test floor(Ti, T(-2.3)) === round(Ti, T(-2.3), RoundDown) === round(Ti, T(-2.3), RoundFromZero) === Ti(-3)
+ @test ceil(Ti, T(-2.7)) === round(Ti, T(-2.7), RoundUp) === Ti(-2)
+ @test round(Ti, T(-1.5)) === round(Ti, T(-2.5)) === round(Ti, T(-1.5), RoundNearest) === round(Ti, T(-2.5), RoundNearest) === Ti(-2)
+ @test round(Ti, T(-2.5), RoundNearestTiesAway) === round(Ti, T(-3.3), RoundNearestTiesAway) === Ti(-3)
+ @test round(Ti, T(-1.5), RoundNearestTiesUp) === round(Ti, T(-0.7), RoundNearestTiesUp) === Ti(-1)
  @test_throws InexactError convert(Ti, yd)
  end
  end