tweak show

Author: jverzani

src/Polynomials.jl

@@ -69,7 +69,7 @@ immutable Poly{T<:Number}
             return new(zeros(T,1), @compat Symbol(var))
         else
             # determine the last nonzero element and truncate a accordingly
-            a_last = max(1,findlast(a))
+            a_last = max(1,findlast(x->x!=zero(T), a))
             new(a[1:a_last], @compat Symbol(var))
         end
     end
@@ -115,6 +115,7 @@ convert{T, S<:Number,n}(::Type{Poly{T}}, x::Array{S,n}) = map(el->convert(Poly{p
 promote_rule{T, S}(::Type{Poly{T}}, ::Type{Poly{S}}) = Poly{promote_type(T, S)}
 promote_rule{T, S<:Number}(::Type{Poly{T}}, ::Type{S}) = Poly{promote_type(T, S)}
 eltype{T}(::Poly{T}) = T
+eltype{T}(::Type{Poly{T}}) = T
 
 """
 
@@ -369,7 +370,7 @@ function polyval{T,S}(p::Poly{T}, x::S)
     if lenp == 0
         return zero(R) * x
     else
-        y = convert(R, p[end]) + 0*x
+        y = convert(R, p[end]) + zero(T)*x
         for i = (endof(p)-1):-1:0
             y = p[i] + x*y
         end

src/show.jl

@@ -5,7 +5,7 @@
 ## which can be modified by users for other Ts
 
 "`hasneg(::T)` attribute is true if: `pj < zero(T)` is defined."
-hasneg{T}(::Type{T}) = true
+hasneg{T}(::Type{T}) = false
 
 "Could value possibly be negative and if so, is it?"
 isneg{T}(pj::T) = hasneg(T) && pj < zero(T)
@@ -20,19 +20,17 @@ showone{T}(::Type{T}) = true
 #####
 
 ## Numbers
+hasneg{T<:Real}(::Type{T}) = true
+
+### Integer
 showone{T<:Integer}(::Type{T}) = false
 showone{T}(::Type{Rational{T}}) = false
 
 
-## Polynomials as coefficients
-hasneg{S}(::Type{Poly{S}}) = false
-showoone{S}(::Type{Poly{S}}) = false
-
 
 
-## Complex coefficients
-## we say neg if real(z) < 0 || real(z) == 0 and imag(g) < 0
-hasneg{T}(::Type{Complex{T}}) = true
+### Complex coefficients
+hasneg{T}(::Type{Complex{T}}) = true      ## we say neg if real(z) < 0 || real(z) == 0 and imag(g) < 0
 
 function isneg{T}(pj::Complex{T})
     real(pj) < 0 && return true
@@ -43,10 +41,16 @@ end
 showone{T}(pj::Type{Complex{T}}) = showone(T)
 
 
+### Polynomials as coefficients
+hasneg{S}(::Type{Poly{S}}) = false
+showone{S}(::Type{Poly{S}}) = false
+
+
+#####
 
 "Show different operations depending on mimetype. `l-` is leading minus sign."
-function showop(::MIME"text/html", op)
-    d = Dict("*" => "&times;", "+" => " &#43; ", "-" => " &#45; ", "l-" => "&#45;")
+function showop(::MIME"text/plain", op)
+    d = Dict("*" => "⋅", "+" => " + ", "-" => " - ", "l-" => "-")
     d[op]
 end
 
@@ -55,8 +59,8 @@ function showop(::MIME"text/latex", op)
     d[op]
 end
 
-function showop(::MIME"text/plain", op)
-    d = Dict("*" => "⋅", "+" => " + ", "-" => " - ", "l-" => "-")
+function showop(::MIME"text/html", op)
+    d = Dict("*" => "&#8729;", "+" => " &#43; ", "-" => " &#45; ", "l-" => "&#45;")
     d[op]
 end
 
@@ -77,6 +81,7 @@ end
 
 function showterm{T}(io::IO,p::Poly{T},j,first, mimetype)
     pj = p[j]
+
     pj == zero(T) && return false
 
     pj = printsign(io, pj, j, first, mimetype)
@@ -114,7 +119,7 @@ function printcoefficient{T}(io::IO, pj::Complex{T}, j, mimetype)
 
     if hasreal & hasimag
         print(io, '(')
-        showio(io, mimetype, pj)
+        show(io, mimetype, pj)
         print(io, ')')
     elseif hasreal
         a = real(pj)
@@ -135,6 +140,7 @@ function printcoefficient{T}(io::IO, pj::T, j, mimetype)
     show(io, mimetype, pj)
 end
 
+## show exponent
 function printexponent(io,var,i, mimetype::MIME"text/latex")
     if i == 0
         return
@@ -158,6 +164,7 @@ end
 
 ####
 
+## text/plain
 @compat Base.show{T}(io::IO, p::Poly{T}) = show(io, MIME("text/plain"), p)
 @compat function Base.show{T}(io::IO, mimetype::MIME"text/plain", p::Poly{T})
     print(io,"Poly(")
@@ -166,6 +173,7 @@ end
 
 end
 
+## text/latex
 @compat function Base.show{T}(io::IO, mimetype::MIME"text/latex", p::Poly{T})
     print(io, "\$")
     printpoly(io, p, mimetype)
@@ -179,3 +187,13 @@ end
 @compat function Base.show{T<:Number}(io::IO, mimetype::MIME"text/latex", a::T)
     print(io, a)
 end
+
+
+## text/html
+@compat function Base.show{T}(io::IO, mimetype::MIME"text/html", p::Poly{T})
+    printpoly(io, p, mimetype)
+end
+
+@compat function Base.show{T<:Number}(io::IO, mimetype::MIME"text/html", a::T)
+    print(io, a)
+end

test/runtests.jl

@@ -184,7 +184,6 @@ p1 = Poly([4,5,6])
 p1[0:1] = [7,8]
 @test all(p1[0:end] .== [7,8,6])
 
-
 ## conjugate of poly (issue #59)
 as = [im, 1, 2]
 bs = [1, 1, 2]
@@ -198,14 +197,47 @@ p2[3] = 3
 @test p1[3] == 3
 
 
+## eltype of a Poly type
+types = [Int, UInt8, Float64]
+for t in types
+  @test t == eltype(Poly{t})
+end
+
+## Polynomials with non-Real type
+import Base: +, *, -
+immutable Mod2 <: Number
+  v::Bool
+end
++(x::Mod2,y::Mod2) = Mod2(x.v$y.v)
+*(x::Mod2,y::Mod2) = Mod2(x.v&y.v)
+-(x::Mod2,y::Mod2) = x+y
+-(x::Mod2) = x
+Base.one(::Type{Mod2}) = Mod2(true)
+Base.zero(::Type{Mod2}) = Mod2(false)
+Base.convert(::Type{Mod2},x::Integer) = Mod2(convert(Bool,x))
+Base.convert(::Type{Bool},x::Mod2) = x.v
+
+# Test that none of this throws
+p = Poly([Mod2(true),Mod2(false), Mod2(true)])
+repr(p)
+@test p(Mod2(false)) == p[0]
+
+
 ## changes to show
 p = Poly([1,2,3,1])  # leading coefficient of 1
-@test string(p) == "Poly(1 + 2⋅x + 3⋅x^2 + x^3)"
+@test repr(p) == "Poly(1 + 2⋅x + 3⋅x^2 + x^3)"
 p = Poly([1.0, 2.0, 3.0, 1.0])
-@test string(p) == "Poly(1.0 + 2.0⋅x + 3.0⋅x^2 + 1.0⋅x^3)"
+@test repr(p) == "Poly(1.0 + 2.0⋅x + 3.0⋅x^2 + 1.0⋅x^3)"
 p = Poly([1+im, 1-im, -1+im, -1 - im])# minus signs
-@test string(p) == "Poly((1 + 1im) + (1 - 1im)⋅x - (1 - 1im)⋅x^2 - (1 + 1im)⋅x^3)"
+@test repr(p) == "Poly((1 + 1im) + (1 - 1im)⋅x - (1 - 1im)⋅x^2 - (1 + 1im)⋅x^3)"
+
+p = Poly([1,2,3])
+@test reprmime("text/latex", p) == "\$1 + 2\\cdot x + 3\\cdot x^{2}\$"
+p = Poly([1//2, 2//3, 1])
+@test reprmime("text/latex", p) == "\$\\frac{1}{2} + \\frac{2}{3}\\cdot x + x^{2}\$"
+
 
+## want to be able to copy and paste
 string_eval_poly(p,x) = eval(Expr(:function, Expr(:call, :f, :x), parse(string(p)[6:end-1])))(x)
 p = Poly([1,2,3]) # copy and paste
 q = Poly([1//1, 2//1, 3//1])