fixing issue #90

isequal() is the primitive comparison function.
  . it defaults to is()
  . is generally only true for arguments of the same type

types with "value type" semantics should define isequal and hash appropriately

subtypes of Number may define == instead of isequal for aesthetics

== defaults to isequal(). only define it for number-like things where
  some special behavior is needed (e.g. type promotion, IEEE-754, etc.)

j/bool.j

@@ -11,7 +11,7 @@ sizeof(::Type{Bool}) = 1
 ## boolean operations ##
 
 !(x::Bool) = eq_int(unbox8(x),trunc8(unbox32(0)))
-==(x::Bool, y::Bool) = eq_int(unbox8(x),unbox8(y))
+isequal(x::Bool, y::Bool) = eq_int(unbox8(x),unbox8(y))
 
 (~)(x::Bool) = !x
 (&)(x::Bool, y::Bool) = (x&&y)

j/complex.j

@@ -132,6 +132,13 @@ pi{T}(::Type{Complex{T}}) = pi(T)
 ## functions of complex numbers ##
 
 ==(z::ComplexNum, w::ComplexNum) = (real(z) == real(w) && imag(z) == imag(w))
+==(z::ComplexNum, x::Real) = (real(z)==x && imag(z)==0)
+==(x::Real, z::ComplexNum) = (real(z)==x && imag(z)==0)
+
+isequal(z::ComplexNum, w::ComplexNum) =
+ isequal(real(z),real(w)) && isequal(imag(z),imag(w))
+
+hash(z::ComplexNum) = bitmix(hash(real(z)),hash(imag(z)))
 
 conj(z::ComplexNum) = complex(real(z),-imag(z))
 norm(z::ComplexNum) = square(real(z)) + square(imag(z))

j/expr.j

@@ -7,8 +7,6 @@ symbol(a::Array{Uint8,1}) =
 
 gensym() = ccall(:jl_gensym, Any, ())::Symbol
 
-(==)(x::Symbol, y::Symbol) = is(x, y)
-
 ## expressions ##
 
 expr(hd::Symbol, args::ANY...) = Expr(hd, {args...}, Any)

j/operators.j

@@ -5,18 +5,21 @@
 
 ## comparison ##
 
-==(x, y) = false
+isequal(x, y) = is(x, y)
+
+==(x, y) = isequal(x, y)
 !=(x, y) = !(x == y)
 ==(x::Number, y::Number) = (==)(promote(x,y)...)
 
+# this definition allows Number types to implement == instead of isequal,
+# which is more idiomatic.
+isequal{T<:Number}(x::T, y::T) = (x == y)
+
 < (x::Real, y::Real) = (<)(promote(x,y)...)
 > (x::Real, y::Real) = (y < x)
 <=(x::Real, y::Real) = (x < y) || (x == y)
 >=(x::Real, y::Real) = (x > y) || (x == y)
 
-isequal{T}(x::T, y::T) = (x==y)
-isequal(x, y) = isequal(promote(x,y)...)
-
 ## definitions providing basic traits of arithmetic operators ##
 
 +() = 0

j/pointer.j

@@ -45,7 +45,7 @@ ulong(x) = convert(Ulong, x)
 
 ## limited pointer arithmetic & comparison ##
 
-==(x::Ptr, y::Ptr) = uint(x) == uint(y)
+isequal(x::Ptr, y::Ptr) = uint(x) == uint(y)
  -(x::Ptr, y::Ptr) = uint(x) - uint(y)
 
 +{T}(x::Ptr{T}, y::Int) = pointer(T, uint(x) + uint(y))

j/process.j

@@ -33,7 +33,7 @@ global STDIN = FileDes(ccall(:jl_stdin, Int32, ()))
 global STDOUT = FileDes(ccall(:jl_stdout, Int32, ()))
 global STDERR = FileDes(ccall(:jl_stderr, Int32, ()))
 
-==(fd1::FileDes, fd2::FileDes) = (fd1.fd == fd2.fd)
+isequal(fd1::FileDes, fd2::FileDes) = (fd1.fd == fd2.fd)
 
 hash(fd::FileDes) = hash(fd.fd)
 
@@ -55,15 +55,15 @@ type Pipe
  end
 end
 
-==(p1::Pipe, p2::Pipe) = (p1.in == p2.in && p1.out == p2.out)
+isequal(p1::Pipe, p2::Pipe) = (p1.in == p2.in && p1.out == p2.out)
 
 abstract PipeEnd
 type PipeIn <: PipeEnd; pipe::Pipe; end
 type PipeOut <: PipeEnd; pipe::Pipe; end
 
-==(p1::PipeEnd, p2::PipeEnd) = false
-==(p1::PipeIn , p2::PipeIn ) = (p1.pipe == p2.pipe)
-==(p1::PipeOut, p2::PipeOut) = (p1.pipe == p2.pipe)
+isequal(p1::PipeEnd, p2::PipeEnd) = false
+isequal(p1::PipeIn , p2::PipeIn ) = (p1.pipe == p2.pipe)
+isequal(p1::PipeOut, p2::PipeOut) = (p1.pipe == p2.pipe)
 
 in (p::Pipe) = PipeIn(p)
 out(p::Pipe) = PipeOut(p)
@@ -170,8 +170,6 @@ end
 
 exec(cmd::Cmd) = exec(cmd.exec)
 
-==(c1::Cmd, c2::Cmd) = is(c1,c2)
-
 ## Port: a file descriptor on a particular command ##
 
 type Port

j/rational.j

@@ -75,10 +75,12 @@ isinf(x::Rational) = x.den == 0 && x.num != 0
 isfinite(x::Rational) = x.den != 0
 
 isequal(x::Rational, y::Rational) = x.num == y.num && x.den == y.den
-isequal(x::Rational, y::Int) = x.den == 1 && x.num == y
-isequal(x::Number, y::Rational) = isequal(y, x)
+
+hash(x::Rational) = bitmix(hash(x.num),hash(x.den))
 
 ==(x::Rational, y::Rational) = !isnan(x) && x.num == y.num && x.den == y.den
+==(x::Rational, y::Int) = x.den == 1 && x.num == y
+==(y::Int, x::Rational) = x.den == 1 && x.num == y
 !=(x::Rational, y::Rational) = isnan(x) || x.num != y.num || x.den != y.den
 <=(x::Rational, y::Rational) = float(x) <= float(y)
 < (x::Rational, y::Rational) = float(x) < float(y)

j/string.j

@@ -120,11 +120,11 @@ function chars(s::String)
  cx
 end
 
-(<) (a::String, b::String) = cmp(a,b) < 0
-(>) (a::String, b::String) = cmp(a,b) > 0
-(==)(a::String, b::String) = cmp(a,b) == 0
-(<=)(a::String, b::String) = cmp(a,b) <= 0
-(>=)(a::String, b::String) = cmp(a,b) >= 0
+(<) (a::String, b::String)  = cmp(a,b) < 0
+(>) (a::String, b::String)  = cmp(a,b) > 0
+isequal(a::String, b::String) = cmp(a,b) == 0
+(<=)(a::String, b::String)  = cmp(a,b) <= 0
+(>=)(a::String, b::String)  = cmp(a,b) >= 0
 
 function cmp(a::String, b::String)
  i = start(a)

j/tensor.j

@@ -451,8 +451,7 @@ function isequal(x::Tensor, y::Tensor)
  end
 
  for i=1:numel(x)
- xi=x[i]; yi=y[i]
- if xi!=yi && !isequal(xi, yi)
+ if !isequal(x[i], y[i])
  return false
  end
  end

j/tuple.j

@@ -46,7 +46,7 @@ map(f, ts::Tuple...) = ntuple(length(ts[1]), n->f(map(t->t[n],ts)...))
 
 ## comparison ##
 
-function ==(t1::Tuple, t2::Tuple)
+function isequal(t1::Tuple, t2::Tuple)
  if length(t1) != length(t2)
  return false
  end

test/tests.j

@@ -224,7 +224,7 @@ b = rand()
 
 for a = -5:5, b = -5:5
  @assert isequal(a/b, a/b)
- @assert isequal(a//b, a/b)
+ @assert (a//b == a/b) || (isnan(a//b) && isnan(a/b))
  @assert isequal(a//b, a//b)
  for c = -5:5, d = -5:5
  @assert isequal(a//b, c//d) == isequal(a/b, c/d)