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| author | Russ Cox <rsc@golang.org> | 2019-01-30 00:55:38 -0500 |
|---|---|---|
| committer | Russ Cox <rsc@golang.org> | 2019-02-26 19:39:19 +0000 |
| commit | d6311ff1e43dd1e7c9cb9edccd10a04b63a7c41f (patch) | |
| tree | fff0d7791115991eba2ac4da9b98dd58d3a30733 /src/math/big | |
| parent | 675503c507194a48c01a39a0f25a6d0c9d772477 (diff) | |
| download | go-d6311ff1e43dd1e7c9cb9edccd10a04b63a7c41f.tar.xz | |
math/big: add %#b and %O integer formats
Matching fmt, %#b now prints an 0b prefix,
and %O prints octal with an 0o prefix.
See golang.org/design/19308-number-literals for background.
For #19308.
For #12711.
Change-Id: I139c5a9a1dfae15415621601edfa13c6a5f19cfc
Reviewed-on: https://go-review.googlesource.com/c/160250
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Diffstat (limited to 'src/math/big')
| -rw-r--r-- | src/math/big/intconv.go | 12 | ||||
| -rw-r--r-- | src/math/big/intconv_test.go | 6 |
2 files changed, 14 insertions, 4 deletions
diff --git a/src/math/big/intconv.go b/src/math/big/intconv.go index 6cca827c8e..65174c5018 100644 --- a/src/math/big/intconv.go +++ b/src/math/big/intconv.go @@ -50,8 +50,9 @@ func writeMultiple(s fmt.State, text string, count int) { var _ fmt.Formatter = intOne // *Int must implement fmt.Formatter // Format implements fmt.Formatter. It accepts the formats -// 'b' (binary), 'o' (octal), 'd' (decimal), 'x' (lowercase -// hexadecimal), and 'X' (uppercase hexadecimal). +// 'b' (binary), 'o' (octal with 0 prefix), 'O' (octal with 0o prefix), +// 'd' (decimal), 'x' (lowercase hexadecimal), and +// 'X' (uppercase hexadecimal). // Also supported are the full suite of package fmt's format // flags for integral types, including '+' and ' ' for sign // control, '#' for leading zero in octal and for hexadecimal, @@ -66,7 +67,7 @@ func (x *Int) Format(s fmt.State, ch rune) { switch ch { case 'b': base = 2 - case 'o': + case 'o', 'O': base = 8 case 'd', 's', 'v': base = 10 @@ -98,6 +99,8 @@ func (x *Int) Format(s fmt.State, ch rune) { prefix := "" if s.Flag('#') { switch ch { + case 'b': // binary + prefix = "0b" case 'o': // octal prefix = "0" case 'x': // hexadecimal @@ -106,6 +109,9 @@ func (x *Int) Format(s fmt.State, ch rune) { prefix = "0X" } } + if ch == 'O' { + prefix = "0o" + } digits := x.abs.utoa(base) if ch == 'X' { diff --git a/src/math/big/intconv_test.go b/src/math/big/intconv_test.go index 2e01ee327d..d23a3e2beb 100644 --- a/src/math/big/intconv_test.go +++ b/src/math/big/intconv_test.go @@ -214,8 +214,12 @@ var formatTests = []struct { {"10", "%y", "%!y(big.Int=10)"}, {"-10", "%y", "%!y(big.Int=-10)"}, - {"10", "%#b", "1010"}, + {"10", "%#b", "0b1010"}, {"10", "%#o", "012"}, + {"10", "%O", "0o12"}, + {"-10", "%#b", "-0b1010"}, + {"-10", "%#o", "-012"}, + {"-10", "%O", "-0o12"}, {"10", "%#d", "10"}, {"10", "%#v", "10"}, {"10", "%#x", "0xa"}, |