Sophisticated show method for toric divisors

docs/src/ToricVarieties/ToricDivisors.md

@@ -43,4 +43,5 @@ isvery_ample(td::ToricDivisor)
 ```@docs
 coefficients(td::ToricDivisor)
 polyhedron(td::ToricDivisor)
+toricvariety(td::ToricDivisor)
 ```

src/ToricVarieties/JToric.jl

@@ -7,6 +7,7 @@ include("NormalToricVarieties/methods.jl")
 include("CyclicQuotientSingularities/CyclicQuotientSingularities.jl")
 
 include("ToricDivisors/constructors.jl")
+include("ToricDivisors/auxilliary.jl")
 include("ToricDivisors/properties.jl")
 include("ToricDivisors/attributes.jl")
 

src/ToricVarieties/ToricDivisors/attributes.jl

@@ -16,7 +16,7 @@ julia> H = hirzebruch_surface(4)
 A normal toric variety corresponding to a polyhedral fan in ambient dimension 2
 
 julia> td0 = ToricDivisor(H, [0,0,0,0])
-A torus invariant divisor on a normal toric variety
+A torus invariant non-prime divisor on a normal toric variety
 
 julia> isfeasible(polyhedron(td0))
 true
@@ -25,13 +25,13 @@ julia> dim(polyhedron(td0))
 0
 
 julia> td1 = ToricDivisor(H, [1,0,0,0])
-A torus invariant divisor on a normal toric variety
+A torus invariant prime divisor on a normal toric variety
 
 julia> isfeasible(polyhedron(td1))
 true
 
 julia> td2 = ToricDivisor(H, [-1,0,0,0])
-A torus invariant divisor on a normal toric variety
+A torus invariant non-prime divisor on a normal toric variety
 
 julia> isfeasible(polyhedron(td2))
 false
@@ -57,7 +57,7 @@ julia> H = hirzebruch_surface(4)
 A normal toric variety corresponding to a polyhedral fan in ambient dimension 2
 
 julia> D = ToricDivisor(H, [1,2,3,4])
-A torus invariant divisor on a normal toric variety
+A torus invariant non-prime divisor on a normal toric variety
 
 julia> coefficients(D)
 4-element Vector{Int64}:
@@ -74,3 +74,14 @@ function coefficients(td::ToricDivisor)
     return get_attribute(td, :coefficients)
 end
 export coefficients
+
+
+@doc Markdown.doc"""
+    toricvariety(td::ToricDivisor)
+
+Return the toric variety of a torus invariant Weil divisor.
+"""
+function toricvariety(td::ToricDivisor)
+    return get_attribute(td, :toricvariety)
+end
+export toricvariety

src/ToricVarieties/ToricDivisors/auxilliary.jl

@@ -0,0 +1,103 @@
+function output_string(td::ToricDivisor)
+
+    # initiate the output string
+    out_string = "A torus invariant"
+
+    # cartier?
+    if has_attribute(td, :iscartier)
+        if get_attribute(td, :iscartier)
+            out_string = out_string * " cartier,";
+        else
+            if has_attribute(td, :isq_cartier)
+                if get_attribute(td, :isq_cartier)
+                    out_string = out_string * " q-cartier,";
+                else
+                    out_string = out_string * " non-q-cartier,";
+                end
+            else
+                out_string = out_string * " non-cartier,";
+            end
+        end
+    end
+
+    # principal?
+    if has_attribute(td, :isprincipal)
+        if get_attribute(td, :isprincipal)
+            out_string = out_string * " principal,";
+        else
+            out_string = out_string * " non-principal,";
+        end
+    end
+
+    # basepoint free?
+    if has_attribute(td, :isbasepoint_free)
+        if get_attribute(td, :isbasepoint_free)
+            out_string = out_string * " basepoint-free,";
+        else
+            out_string = out_string * " non-basepoint-free,";
+        end
+    end
+
+    # effective?
+    if has_attribute(td, :iseffective)
+        if get_attribute(td, :iseffective)
+            out_string = out_string * " effective,";
+        else
+            out_string = out_string * " non-effective,";
+        end
+    end
+
+    # integral?
+    if has_attribute(td, :isintegral)
+        if get_attribute(td, :isintegral)
+            out_string = out_string * " integral,";
+        else
+            out_string = out_string * " non-integral,";
+        end
+    end
+
+    # (very) ample?
+    if has_attribute(td, :isample)
+        if get_attribute(td, :isample)
+            out_string = out_string * " ample,";
+        else
+            if has_attribute(td, :isvery_ample)
+                if get_attribute(td, :isvery_ample)
+                    out_string = out_string * " very-ample,";
+                else
+                    out_string = out_string * " non-very-ample,";
+                end
+            else
+                out_string = out_string * " non-ample,";
+            end
+        end
+    end
+
+    # nef?
+    if has_attribute(td, :isnef)
+        if get_attribute(td, :isnef)
+            out_string = out_string * " nef,";
+        else
+            out_string = out_string * " non-nef,";
+        end
+    end
+
+    # prime divisor?
+    if has_attribute(td, :isprime_divisor)
+        if get_attribute(td, :isprime_divisor)
+            out_string = out_string * " prime";
+        else
+            out_string = out_string * " non-prime";
+        end
+    end
+
+    # torusfactor?
+    if last(out_string) == ','
+        out_string = chop(out_string)
+    end
+    out_string = out_string * " divisor on a" * chop(output_string(toricvariety(td)), head = 1, tail = 0)
+
+    # return result
+    return out_string
+
+end

src/ToricVarieties/ToricDivisors/constructors.jl

@@ -23,8 +23,8 @@ Construct the torus invariant divisor on the normal toric variety `v` as linear
 
 # Examples
 ```jldoctest
-julia> show(ToricDivisor(toric_projective_space(2), [1,1,2]))
-A torus invariant divisor on a normal toric variety
+julia> ToricDivisor(toric_projective_space(2), [1,1,2])
+A torus invariant non-prime divisor on a normal non-affine, smooth, projective, gorenstein, q-gorenstein, fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 ```
 """
 function ToricDivisor(v::AbstractNormalToricVariety, coeffs::Vector{Int})
@@ -40,6 +40,7 @@ function ToricDivisor(v::AbstractNormalToricVariety, coeffs::Vector{Int})
 
     # set attributes
     set_attribute!(td, :coefficients, coeffs)
+    set_attribute!(td, :toricvariety, v)
     if sum(coeffs) != 1
         set_attribute!(td, :isprime_divisor, false)
     else
@@ -63,8 +64,8 @@ Construct the torus invariant divisor associated to a character of the normal to
 
 # Examples
 ```jldoctest
-julia> show(DivisorOfCharacter(toric_projective_space(2), [1,2]))
-A torus invariant divisor on a normal toric variety
+julia> DivisorOfCharacter(toric_projective_space(2), [1,2])
+A torus invariant non-prime divisor on a normal non-affine, smooth, projective, gorenstein, q-gorenstein, fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 ```
 """
 function DivisorOfCharacter(v::AbstractNormalToricVariety, character::Vector{Int})
@@ -79,11 +80,10 @@ end
 export DivisorOfCharacter
 
 
-###############################################################################
-###############################################################################
+######################
 ### 4: Display
-###############################################################################
-###############################################################################
+######################s
+
 function Base.show(io::IO, td::ToricDivisor)
-    print(io, "A torus invariant divisor on a normal toric variety")
+    print(io, output_string(td))
 end

src/ToricVarieties/ToricDivisors/properties.jl

@@ -9,7 +9,7 @@ julia> H = hirzebruch_surface(4)
 A normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> td = ToricDivisor(H, [1,0,0,0])
-A torus invariant divisor on a normal toric variety
+A torus invariant prime divisor on a normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> iscartier(td)
 true
@@ -34,7 +34,7 @@ julia> H = hirzebruch_surface(4)
 A normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> td = ToricDivisor(H, [1,0,0,0])
-A torus invariant divisor on a normal toric variety
+A torus invariant prime divisor on a normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> isprincipal(td)
 false
@@ -59,7 +59,7 @@ julia> H = hirzebruch_surface(4)
 A normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> td = ToricDivisor(H, [1,0,0,0])
-A torus invariant divisor on a normal toric variety
+A torus invariant prime divisor on a normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> isbasepoint_free(td)
 true
@@ -84,7 +84,7 @@ julia> H = hirzebruch_surface(4)
 A normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> td = ToricDivisor(H, [1,0,0,0])
-A torus invariant divisor on a normal toric variety
+A torus invariant prime divisor on a normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> iseffective(td)
 true
@@ -109,7 +109,7 @@ julia> H = hirzebruch_surface(4)
 A normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> td = ToricDivisor(H, [1,0,0,0])
-A torus invariant divisor on a normal toric variety
+A torus invariant prime divisor on a normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> isintegral(td)
 true
@@ -134,7 +134,7 @@ julia> H = hirzebruch_surface(4)
 A normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> td = ToricDivisor(H, [1,0,0,0])
-A torus invariant divisor on a normal toric variety
+A torus invariant prime divisor on a normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> isample(td)
 false
@@ -159,7 +159,7 @@ julia> H = hirzebruch_surface(4)
 A normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> td = ToricDivisor(H, [1,0,0,0])
-A torus invariant divisor on a normal toric variety
+A torus invariant prime divisor on a normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> isvery_ample(td)
 false
@@ -184,7 +184,7 @@ julia> H = hirzebruch_surface(4)
 A normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> td = ToricDivisor(H, [1,0,0,0])
-A torus invariant divisor on a normal toric variety
+A torus invariant prime divisor on a normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> isnef(td)
 true
@@ -209,7 +209,7 @@ julia> H = hirzebruch_surface(4)
 A normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> td = ToricDivisor(H, [1,0,0,0])
-A torus invariant divisor on a normal toric variety
+A torus invariant prime divisor on a normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> isq_cartier(td)
 true
@@ -235,7 +235,7 @@ julia> H = hirzebruch_surface(4)
 A normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> td = ToricDivisor(H, [1,0,0,0])
-A torus invariant divisor on a normal toric variety
+A torus invariant prime divisor on a normal non-affine, smooth, projective, gorenstein, q-gorenstein, non-fano toric variety without torusfactor corresponding to a polyhedral fan in ambient dimension 2
 
 julia> isprime_divisor(td)
 true

test/ToricVarieties/runtests.jl

@@ -195,6 +195,7 @@ D=ToricDivisor(H5, [0,0,0,0])
 D2 = DivisorOfCharacter(H5, [1,2])
 
 @testset "Divisors" begin
+    @test dim(toricvariety(D)) == 2
     @test isprime_divisor(D) == false
     @test iscartier(D) == true
     @test isprincipal(D) == true