fmt: make %F a synonym for %f

Rationale:
        It already is for scanning.
        It is accepted for complexes already, but doesn't work.
        It's analogous to %G and %E.
        C accepts it too, and we try to be roughly compatible.
Fixes #7518.

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/77580044

diff --git a/src/pkg/fmt/doc.go b/src/pkg/fmt/doc.go
index 7a7b63bd6b12d75fe3995197202e0dfd6bd37eca..7a14b80894d055768078a6676f4a8f8f9223cc24 100644 (file)
--- a/src/pkg/fmt/doc.go
+++ b/src/pkg/fmt/doc.go
@@ -37,6 +37,7 @@
                %e      scientific notation, e.g. -1234.456e+78
                %E      scientific notation, e.g. -1234.456E+78
                %f      decimal point but no exponent, e.g. 123.456
+               %F      synonym for %f
                %g      whichever of %e or %f produces more compact output
                %G      whichever of %E or %f produces more compact output
        String and slice of bytes:

diff --git a/src/pkg/fmt/fmt_test.go b/src/pkg/fmt/fmt_test.go
index 14a1a56c0458bde9e73c0e055c5738b2f8df1dfa..c7a09dedd9f8f0d81aaafdcf450947dd129c5092 100644 (file)
--- a/src/pkg/fmt/fmt_test.go
+++ b/src/pkg/fmt/fmt_test.go
@@ -220,6 +220,8 @@ var fmtTests = []struct {
        {"%+.3e", 0.0, "+0.000e+00"},
        {"%+.3e", 1.0, "+1.000e+00"},
        {"%+.3f", -1.0, "-1.000"},
+       {"%+.3F", -1.0, "-1.000"},
+       {"%+.3F", float32(-1.0), "-1.000"},
        {"%+07.2f", 1.0, "+001.00"},
        {"%+07.2f", -1.0, "-001.00"},
        {"% .3E", -1.0, "-1.000E+00"},
@@ -241,6 +243,8 @@ var fmtTests = []struct {
        {"%+.3g", 1 + 2i, "(+1+2i)"},
        {"%.3e", 0i, "(0.000e+00+0.000e+00i)"},
        {"%.3f", 0i, "(0.000+0.000i)"},
+       {"%.3F", 0i, "(0.000+0.000i)"},
+       {"%.3F", complex64(0i), "(0.000+0.000i)"},
        {"%.3g", 0i, "(0+0i)"},
        {"%.3e", 1 + 2i, "(1.000e+00+2.000e+00i)"},
        {"%.3f", 1 + 2i, "(1.000+2.000i)"},

diff --git a/src/pkg/fmt/format.go b/src/pkg/fmt/format.go
index 3835aa9823a0e0f2f4b1253f64c70328d03c8fcd..b0f4ad4b73046915082888a306d5f9b67d8bcace 100644 (file)
--- a/src/pkg/fmt/format.go
+++ b/src/pkg/fmt/format.go
@@ -447,7 +447,7 @@ func (f *fmt) fmt_c64(v complex64, verb rune) {
                        f.fmt_e32(r)
                case 'E':
                        f.fmt_E32(r)
-               case 'f':
+               case 'f', 'F':
                        f.fmt_f32(r)
                case 'g':
                        f.fmt_g32(r)
@@ -477,7 +477,7 @@ func (f *fmt) fmt_c128(v complex128, verb rune) {
                        f.fmt_e64(r)
                case 'E':
                        f.fmt_E64(r)
-               case 'f':
+               case 'f', 'F':
                        f.fmt_f64(r)
                case 'g':
                        f.fmt_g64(r)

diff --git a/src/pkg/fmt/print.go b/src/pkg/fmt/print.go
index 2f13bcd95e971415401e75a10b0f7d36d209d930..c56d5b94010d23b9ff6a7ef03465e3606f7d4b14 100644 (file)
--- a/src/pkg/fmt/print.go
+++ b/src/pkg/fmt/print.go
@@ -447,7 +447,7 @@ func (p *pp) fmtFloat32(v float32, verb rune) {
                p.fmt.fmt_e32(v)
        case 'E':
                p.fmt.fmt_E32(v)
-       case 'f':
+       case 'f', 'F':
                p.fmt.fmt_f32(v)
        case 'g', 'v':
                p.fmt.fmt_g32(v)
@@ -466,7 +466,7 @@ func (p *pp) fmtFloat64(v float64, verb rune) {
                p.fmt.fmt_e64(v)
        case 'E':
                p.fmt.fmt_E64(v)
-       case 'f':
+       case 'f', 'F':
                p.fmt.fmt_f64(v)
        case 'g', 'v':
                p.fmt.fmt_g64(v)