Require non-zero coefficient ring in laurent/puiseux constructions (#…

…1861)

docs/src/constructors.md

@@ -74,7 +74,7 @@ AbstractAlgebra.jl and explain what mathematical domains they represent.
 | $S = K((x))$ (to precision $n$)      | `S, x = laurent_series_field(K, n, :x)`               |
 | $S = R((x, y))$ (to precision $n$)   | `S, (x, y) = laurent_polynomial_ring(R, n, [:x, :y])` |
 | Puiseux series ring to precision $n$ | `S, x = puiseux_series_ring(R, n, :x)`                |
-| Puiseux series field to precision $n$| `S, x = puiseux_series_field(R, n, :x)`               |
+| Puiseux series field to precision $n$| `S, x = puiseux_series_field(K, n, :x)`               |
 | $S = K(x)(y)/(f)$                    | `S, y = function_field(f, :y)` with $f\in K(x)[t]$    |
 | $S = \mathrm{Frac}_R$                | `S = fraction_field(R)`                               |
 | $S = R/(f)$                          | `S, = residue_ring(R, f)`                              |

src/LaurentPoly.jl

@@ -39,5 +39,7 @@ julia> rand(R, -3:3, -9:9)
 -3*x^2 - 8*x + 4 + 3*x^-1 - 6*x^-2 + 9*x^-3
 ```
 """
-laurent_polynomial_ring(R::Ring, s::VarName; cached::Bool = true) =
-   Generic.laurent_polynomial_ring(R, Symbol(s); cached)
+function laurent_polynomial_ring(R::Ring, s::VarName; cached::Bool = true)
+   @req !is_trivial(R) "Zero rings are currently not supported as coefficient ring."
+   return Generic.laurent_polynomial_ring(R, Symbol(s); cached)
+end

src/LaurentSeries.jl

@@ -24,8 +24,10 @@ object `S` will be cached so that supplying the same base ring, string and
 precision in future will return the same parent object and generator. If
 caching of the parent object is not required, `cached` can be set to `false`.
 """
-laurent_series_ring(R::Ring, prec::Int, s::VarName; cached::Bool=true) =
-   Generic.laurent_series_ring(R, prec, Symbol(s); cached)
+function laurent_series_ring(R::Ring, prec::Int, s::VarName; cached::Bool=true)
+   @req !is_trivial(R) "Zero rings are currently not supported as coefficient ring."
+   return Generic.laurent_series_ring(R, prec, Symbol(s); cached)
+end
 
 @doc raw"""
     laurent_series_field(R::Field, prec::Int, s::VarName; cached::Bool=true)

src/PuiseuxSeries.jl

@@ -24,8 +24,11 @@ object `S` will be cached so that supplying the same base ring, string and
 precision in future will return the same parent object and generator. If
 caching of the parent object is not required, `cached` can be set to `false`.
 """
-puiseux_series_ring(R::Ring, prec::Int, s::VarName; cached::Bool=true) =
-   Generic.PuiseuxSeriesRing(R, prec, Symbol(s); cached)
+function puiseux_series_ring(R::Ring, prec::Int, s::VarName; cached::Bool=true)
+   @req !is_trivial(R) "Zero rings are currently not supported as coefficient ring."
+   return Generic.PuiseuxSeriesRing(R, prec, Symbol(s); cached)
+end
 
-puiseux_series_field(R::Field, prec::Int, s::VarName; cached::Bool=true) =
-   Generic.PuiseuxSeriesField(R, prec, Symbol(s); cached)
+function puiseux_series_field(R::Field, prec::Int, s::VarName; cached::Bool=true)
+   return Generic.PuiseuxSeriesField(R, prec, Symbol(s); cached)
+end

src/generic/LaurentMPoly.jl

@@ -635,6 +635,7 @@ end
 ###############################################################################
 
 function laurent_polynomial_ring(R::AbstractAlgebra.Ring, s::Vector{Symbol}; cached::Bool = true)
+   @req !is_trivial(R) "Zero rings are currently not supported as coefficient ring."
    P, x = AbstractAlgebra.polynomial_ring(R, s, cached = cached)
    R = LaurentMPolyWrapRing(P, cached)
    R, map(p -> LaurentMPolyWrap(R, p), x)

src/generic/LaurentPoly.jl

@@ -508,6 +508,7 @@ end
 ###############################################################################
 
 function laurent_polynomial_ring(R::AbstractAlgebra.Ring, s::Symbol; cached::Bool = true)
+   @req !is_trivial(R) "Zero rings are currently not supported as coefficient ring."
    P, x = AbstractAlgebra.polynomial_ring(R, s, cached = cached)
    R = LaurentPolyWrapRing(P, cached)
    R, LaurentPolyWrap(R, x)