Add conversion QQBar -> Float64

Nemocas · Oct 15, 2024 · f354cc7 · f354cc7
1 parent 8fac1af
commit f354cc7
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Showing 3 changed files with 18 additions and 9 deletions.
diff --git a/src/calcium/ca.jl b/src/calcium/ca.jl
@@ -1363,11 +1363,9 @@ end
 
 function (::Type{ComplexF64})(x::CalciumFieldElem)
   z = AcbField(53, cached = false)(x)
-  x = ArbFieldElem()
-  ccall((:acb_get_real, libflint), Nothing, (Ref{ArbFieldElem}, Ref{AcbFieldElem}), x, z)
+  x = real(z)
   xx = Float64(x)
-  y = ArbFieldElem()
-  ccall((:acb_get_imag, libflint), Nothing, (Ref{ArbFieldElem}, Ref{AcbFieldElem}), y, z)
+  y = imag(z)
   yy = Float64(y)
   return ComplexF64(xx, yy)
 end

diff --git a/src/calcium/qqbar.jl b/src/calcium/qqbar.jl
@@ -1485,16 +1485,21 @@ function ZZRingElem(a::QQBarFieldElem)
 end
 
 function (::Type{ComplexF64})(x::QQBarFieldElem)
-  z = AcbField(53, cached = false)(x)
-  x = ArbFieldElem()
-  ccall((:acb_get_real, libflint), Nothing, (Ref{ArbFieldElem}, Ref{AcbFieldElem}), x, z)
+  z = AcbField(57, cached = false)(x)
+  x = real(z)
   xx = Float64(x)
-  y = ArbFieldElem()
-  ccall((:acb_get_imag, libflint), Nothing, (Ref{ArbFieldElem}, Ref{AcbFieldElem}), y, z)
+  y = imag(z)
   yy = Float64(y)
   return ComplexF64(xx, yy)
 end
 
+function (::Type{Float64})(x::QQBarFieldElem)
+  isreal(x) || throw(InexactError(:Float64, Float64, x))
+  z = AcbField(57, cached = false)(x)
+  x = real(z)
+  return Float64(x)
+end
+
 ###############################################################################
 #
 #   Unsafe functions

diff --git a/test/calcium/qqbar-test.jl b/test/calcium/qqbar-test.jl
@@ -400,6 +400,12 @@ end
       @test contains(ComplexField()(a), ComplexField()(b))
     end
   end
+
+  x = sqrt(R(2))
+  @test isapprox(Float64(x), sqrt(2))
+
+  x = sqrt(R(-2))
+  @test_throws InexactError Float64(x)
 end
 
 function test_elem(R::QQBarField)