Merge branch 'master' of github.com:JuliaLang/julia

Author: JeffBezanson

j/intfuncs.j

@@ -73,7 +73,7 @@ function power_by_squaring(x, p::Int)
     elseif p == 0
         return one(x)
     elseif p < 0
-        return inv(x^(-p))
+        error("power_by_squaring: exponent must be >= 0, got $p")
     elseif p == 2
         return x*x
     end
@@ -101,8 +101,8 @@ function power_by_squaring(x, p::Int)
 end
 
 ^(x, p::Int)          = power_by_squaring(x,p)
-^(x::Int, p::Int)     = power_by_squaring(float64(x),p)
-^{T<:Int}(x::T, p::T) = power_by_squaring(float64(x),p)
+^(x::Int, p::Int)     = p < 0 ? inv(x^(-p)) : power_by_squaring(float64(x),p)
+^{T<:Int}(x::T, p::T) = p < 0 ? inv(x^(-p)) : power_by_squaring(float64(x),p)
 
 # x^p mod m
 function powermod(x::Int, p::Int, m::Int)

j/operators.j

@@ -92,6 +92,11 @@ sizeof{T}(x::T) = sizeof(T)
 copy(x::ANY) = x
 foreach(f::Function, itr) = for x = itr; f(x); end
 
+# function composition
+one(f::Function) = identity
+one(::Type{Function}) = identity
+*(f::Function, g::Function) = x->f(g(x))
+
 # vectorization
 
 macro vectorize_1arg(S,f)

j/rational.j

@@ -87,8 +87,8 @@ isequal(x::Rational, y::Rational) = x.num == y.num && x.den == y.den
 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::Int) = x.den == 1 && x.num == y
+==(y::Int, x::Rational) = x.den == 1 && x.num == y
 
 <=(x::Rational, y::Rational) = float(x) <= float(y) # TODO: better comparison
 < (x::Rational, y::Rational) = float(x) < float(y)  # TODO: better comparison

j/string.j

@@ -219,8 +219,12 @@ end
 length(s::RepString) = length(s.string)*s.repeat
 strlen(s::RepString) = strlen(s.string)*s.repeat
 
-repeat(s::String, r::Int) = r <= 0 ? "" :
-                            r == 1 ? s  : RepString(s,r)
+function repeat(s::String, r::Int)
+    r <  0 ? error("can't repeat a string ",r," times") :
+    r == 0 ? "" :
+    r == 1 ? s  :
+    RepString(s,r)
+end
 
 ## ropes for efficient concatenation, etc. ##
 

j/sysimg.j

@@ -30,17 +30,16 @@ load("table.j")
 
 # compiler
 load("inference.j")
-ccall(:jl_enable_inference,Void,())
+ccall(:jl_enable_inference, Void, ())
 
 # strings & printing
 load("io.j")
 ccall(:jl_set_memio_func, Void, ())
-set_current_output_stream(make_stdout_stream())  # for error reporting
+set_current_output_stream(make_stdout_stream()) # for error reporting
 load("string.j")
 load("ascii.j")
 load("utf8.j")
 load("show.j")
-
 load("env.j")
 
 # core math functions

src/boot.j

@@ -269,7 +269,7 @@ end
 
 append(xs...) = append_any(xs...)
 
-identity = x->x
+identity(x) = x
 
 macro thunk(ex); :(()->$ex); end
 macro L_str(s); s; end