Merge pull request #56 from JuliaString/spj/round

Update calls to round, change signif to round

Author: jmkuhn

README.md

@@ -2,9 +2,8 @@
 
 This package offers Python-style general formatting and c-style numerical formatting (for speed).
 
-[![Build Status](https://travis-ci.org/JuliaIO/Formatting.jl.svg?branch=master)](https://travis-ci.org/JuliaIO/Formatting.jl)
-[![Formatting](http://pkg.julialang.org/badges/Formatting_0.4.svg)](http://pkg.julialang.org/?pkg=Formatting&ver=0.4)
-[![Formatting](http://pkg.julialang.org/badges/Formatting_0.5.svg)](http://pkg.julialang.org/?pkg=Formatting&ver=0.5)
+[![Formatting](http://pkg.julialang.org/badges/Formatting_0.6.svg)](http://pkg.julialang.org/?pkg=Formatting&ver=0.6)
+[![Formatting](http://pkg.julialang.org/badges/Formatting_0.7.svg)](http://pkg.julialang.org/?pkg=Formatting&ver=0.7)
 
 ---------------
 

src/fmtcore.jl

@@ -171,7 +171,8 @@ end
 
 function _pfmt_f(out::IO, fs::FormatSpec, x::AbstractFloat)
     # separate sign, integer, and decimal part
-    rax = round(abs(x), fs.prec)
+    rax = (@static VERSION < v"0.7.0-DEV.4804" ? round(abs(x), fs.prec) :
+           round(abs(x); digits=fs.prec))
     sch = _signchar(x, fs.sign)
     intv = trunc(Integer, rax)
     decv = rax - intv
@@ -218,6 +219,36 @@ function _pfmt_floate(out::IO, sch::Char, zs::Integer, u::Real, prec::Int, e::In
 end
 
 
+# Pull in definition of signif from v0.6.2 base, since it is currently broken for
+# BigFloat and DecFP (at least) on master
+
+@static if VERSION >= v"0.7.0-DEV.4804"
+# adapted from Matlab File Exchange roundsd: http://www.mathworks.com/matlabcentral/fileexchange/26212
+# for round, og is the power of 10 relative to the decimal point
+# for signif, og is the absolute power of 10
+# digits and base must be integers, x must be convertable to float
+
+function signif(x::Real, digits::Integer, base::Integer=10)
+    digits < 1 && throw(DomainError())
+
+    x = float(x)
+    (x == 0 || !isfinite(x)) && return x
+    if base == 10
+        e = floor(log10(abs(x)) - digits + 1.)
+        og = oftype(x, exp10(abs(e)))
+    elseif base == 2
+        e = exponent(abs(x)) - digits + 1.
+        og = oftype(x, exp2(abs(e)))
+    else
+        e = floor(log(base, abs(x)) - digits + 1.)
+        og = oftype(x, float(base) ^ abs(e))
+    end
+    # for numeric stability
+    r = e >= 0 ? round(x/og)*og : round(x*og)/og
+    isfinite(r) ? r : x
+end
+end
+
 function _pfmt_e(out::IO, fs::FormatSpec, x::AbstractFloat)
     # extract sign, significand, and exponent
     ax = abs(x)
@@ -226,7 +257,7 @@ function _pfmt_e(out::IO, fs::FormatSpec, x::AbstractFloat)
         e = 0
         u = zero(x)
     else
-        rax = signif(ax, fs.prec + 1)
+        rax = signif(ax, fs.prec + 1) # round(ax; sigdigits = fs.prec + 1)
         e = floor(Integer, log10(rax))  # exponent
         u = rax * exp10(-e)  # significand
     end