--- /dev/null
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package strconv
+
+const fnParseComplex = "ParseComplex"
+
+// convErr splits an error returned by parseFloatPrefix
+// into a syntax or range error for ParseComplex.
+func convErr(err error, s string) (syntax, range_ error) {
+ if x, ok := err.(*NumError); ok {
+ x.Func = fnParseComplex
+ x.Num = s
+ if x.Err == ErrRange {
+ return nil, x
+ }
+ }
+ return err, nil
+}
+
+// ParseComplex converts the string s to a complex number
+// with the precision specified by bitSize: 64 for complex64, or 128 for complex128.
+// When bitSize=64, the result still has type complex128, but it will be
+// convertible to complex64 without changing its value.
+//
+// The number represented by s must be of the form N, Ni, or N±Ni, where N stands
+// for a floating-point number as recognized by ParseFloat, and i is the imaginary
+// component. If the second N is unsigned, a + sign is required between the two components
+// as indicated by the ±. If the second N is NaN, only a + sign is accepted.
+// The form may be parenthesized and cannot contain any spaces.
+// The resulting complex number consists of the two components converted by ParseFloat.
+//
+// The errors that ParseComplex returns have concrete type *NumError
+// and include err.Num = s.
+//
+// If s is not syntactically well-formed, ParseComplex returns err.Err = ErrSyntax.
+//
+// If s is syntactically well-formed but either component is more than 1/2 ULP
+// away from the largest floating point number of the given component's size,
+// ParseComplex returns err.Err = ErrRange and c = ±Inf for the respective component.
+func ParseComplex(s string, bitSize int) (complex128, error) {
+ size := 128
+ if bitSize == 64 {
+ size = 32 // complex64 uses float32 parts
+ }
+
+ orig := s
+
+ // Remove parentheses, if any.
+ if len(s) >= 2 && s[0] == '(' && s[len(s)-1] == ')' {
+ s = s[1 : len(s)-1]
+ }
+
+ var pending error // pending range error, or nil
+
+ // Read real part (possibly imaginary part if followed by 'i').
+ re, n, err := parseFloatPrefix(s, size)
+ if err != nil {
+ err, pending = convErr(err, orig)
+ if err != nil {
+ return 0, err
+ }
+ }
+ s = s[n:]
+
+ // If we have nothing left, we're done.
+ if len(s) == 0 {
+ return complex(re, 0), pending
+ }
+
+ // Otherwise, look at the next character.
+ switch s[0] {
+ case '+':
+ // Consume the '+' to avoid an error if we have "+NaNi", but
+ // do this only if we don't have a "++" (don't hide that error).
+ if len(s) > 1 && s[1] != '+' {
+ s = s[1:]
+ }
+ case '-':
+ // ok
+ case 'i':
+ // If 'i' is the last character, we only have an imaginary part.
+ if len(s) == 1 {
+ return complex(0, re), pending
+ }
+ fallthrough
+ default:
+ return 0, syntaxError(fnParseComplex, orig)
+ }
+
+ // Read imaginary part.
+ im, n, err := parseFloatPrefix(s, size)
+ if err != nil {
+ err, pending = convErr(err, orig)
+ if err != nil {
+ return 0, err
+ }
+ }
+ s = s[n:]
+ if s != "i" {
+ return 0, syntaxError(fnParseComplex, orig)
+ }
+ return complex(re, im), pending
+}
--- /dev/null
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package strconv_test
+
+import (
+ "math"
+ "math/cmplx"
+ "reflect"
+ . "strconv"
+ "testing"
+)
+
+var (
+ infp0 = complex(math.Inf(+1), 0)
+ infm0 = complex(math.Inf(-1), 0)
+ inf0p = complex(0, math.Inf(+1))
+ inf0m = complex(0, math.Inf(-1))
+ infpp = complex(math.Inf(+1), math.Inf(+1))
+ infpm = complex(math.Inf(+1), math.Inf(-1))
+ infmp = complex(math.Inf(-1), math.Inf(+1))
+ infmm = complex(math.Inf(-1), math.Inf(-1))
+)
+
+type atocTest struct {
+ in string
+ out complex128
+ err error
+}
+
+func TestParseComplex(t *testing.T) {
+
+ tests := []atocTest{
+ // Clearly invalid
+ {"", 0, ErrSyntax},
+ {" ", 0, ErrSyntax},
+ {"(", 0, ErrSyntax},
+ {")", 0, ErrSyntax},
+ {"i", 0, ErrSyntax},
+ {"+i", 0, ErrSyntax},
+ {"-i", 0, ErrSyntax},
+ {"1I", 0, ErrSyntax},
+ {"10 + 5i", 0, ErrSyntax},
+ {"3+", 0, ErrSyntax},
+ {"3+5", 0, ErrSyntax},
+ {"3+5+5i", 0, ErrSyntax},
+ // Parentheses
+ {"()", 0, ErrSyntax},
+ {"(i)", 0, ErrSyntax},
+ {"(0)", 0, nil},
+ {"(1i)", 1i, nil},
+ {"(3.0+5.5i)", 3.0 + 5.5i, nil},
+ {"(1)+1i", 0, ErrSyntax},
+ {"(3.0+5.5i", 0, ErrSyntax},
+ {"3.0+5.5i)", 0, ErrSyntax},
+ // NaNs
+ {"NaN", complex(math.NaN(), 0), nil},
+ {"NANi", complex(0, math.NaN()), nil},
+ {"nan+nAni", complex(math.NaN(), math.NaN()), nil},
+ {"+NaN", 0, ErrSyntax},
+ {"-NaN", 0, ErrSyntax},
+ {"NaN-NaNi", 0, ErrSyntax},
+ // Infs
+ {"Inf", infp0, nil},
+ {"+inf", infp0, nil},
+ {"-inf", infm0, nil},
+ {"Infinity", infp0, nil},
+ {"+INFINITY", infp0, nil},
+ {"-infinity", infm0, nil},
+ {"+infi", inf0p, nil},
+ {"0-infinityi", inf0m, nil},
+ {"Inf+Infi", infpp, nil},
+ {"+Inf-Infi", infpm, nil},
+ {"-Infinity+Infi", infmp, nil},
+ {"inf-inf", 0, ErrSyntax},
+ // Zeros
+ {"0", 0, nil},
+ {"0i", 0, nil},
+ {"-0.0i", 0, nil},
+ {"0+0.0i", 0, nil},
+ {"0e+0i", 0, nil},
+ {"0e-0+0i", 0, nil},
+ {"-0.0-0.0i", 0, nil},
+ {"0e+012345", 0, nil},
+ {"0x0p+012345i", 0, nil},
+ {"0x0.00p-012345i", 0, nil},
+ {"+0e-0+0e-0i", 0, nil},
+ {"0e+0+0e+0i", 0, nil},
+ {"-0e+0-0e+0i", 0, nil},
+ // Regular non-zeroes
+ {"0.1", 0.1, nil},
+ {"0.1i", 0 + 0.1i, nil},
+ {"0.123", 0.123, nil},
+ {"0.123i", 0 + 0.123i, nil},
+ {"0.123+0.123i", 0.123 + 0.123i, nil},
+ {"99", 99, nil},
+ {"+99", 99, nil},
+ {"-99", -99, nil},
+ {"+1i", 1i, nil},
+ {"-1i", -1i, nil},
+ {"+3+1i", 3 + 1i, nil},
+ {"30+3i", 30 + 3i, nil},
+ {"+3e+3-3e+3i", 3e+3 - 3e+3i, nil},
+ {"+3e+3+3e+3i", 3e+3 + 3e+3i, nil},
+ {"+3e+3+3e+3i+", 0, ErrSyntax},
+ // Separators
+ {"0.1", 0.1, nil},
+ {"0.1i", 0 + 0.1i, nil},
+ {"0.1_2_3", 0.123, nil},
+ {"+0x_3p3i", 0x3p3i, nil},
+ {"0x_10.3p-8+0x3p3i", 0x10.3p-8 + 0x3p3i, nil},
+ {"+0x_1_0.3p-8+0x3p3i", 0x10.3p-8 + 0x3p3i, nil},
+ {"0x10.3p+8-0x_3p3i", 0x10.3p+8 - 0x3p3i, nil},
+ // Hexadecimals
+ {"0x10.3p-8+0x3p3i", 0x10.3p-8 + 0x3p3i, nil},
+ {"+0x10.3p-8+0x3p3i", 0x10.3p-8 + 0x3p3i, nil},
+ {"0x10.3p+8-0x3p3i", 0x10.3p+8 - 0x3p3i, nil},
+ {"0x1p0", 1, nil},
+ {"0x1p1", 2, nil},
+ {"0x1p-1", 0.5, nil},
+ {"0x1ep-1", 15, nil},
+ {"-0x1ep-1", -15, nil},
+ {"-0x2p3", -16, nil},
+ {"0x1e2", 0, ErrSyntax},
+ {"1p2", 0, ErrSyntax},
+ {"0x1e2i", 0, ErrSyntax},
+ // ErrRange
+ // next float64 - too large
+ {"+0x1p1024", infp0, ErrRange},
+ {"-0x1p1024", infm0, ErrRange},
+ {"+0x1p1024i", inf0p, ErrRange},
+ {"-0x1p1024i", inf0m, ErrRange},
+ {"+0x1p1024+0x1p1024i", infpp, ErrRange},
+ {"+0x1p1024-0x1p1024i", infpm, ErrRange},
+ {"-0x1p1024+0x1p1024i", infmp, ErrRange},
+ {"-0x1p1024-0x1p1024i", infmm, ErrRange},
+ // the border is ...158079
+ // borderline - okay
+ {"+0x1.fffffffffffff7fffp1023+0x1.fffffffffffff7fffp1023i", 1.7976931348623157e+308 + 1.7976931348623157e+308i, nil},
+ {"+0x1.fffffffffffff7fffp1023-0x1.fffffffffffff7fffp1023i", 1.7976931348623157e+308 - 1.7976931348623157e+308i, nil},
+ {"-0x1.fffffffffffff7fffp1023+0x1.fffffffffffff7fffp1023i", -1.7976931348623157e+308 + 1.7976931348623157e+308i, nil},
+ {"-0x1.fffffffffffff7fffp1023-0x1.fffffffffffff7fffp1023i", -1.7976931348623157e+308 - 1.7976931348623157e+308i, nil},
+ // borderline - too large
+ {"+0x1.fffffffffffff8p1023", infp0, ErrRange},
+ {"-0x1fffffffffffff.8p+971", infm0, ErrRange},
+ {"+0x1.fffffffffffff8p1023i", inf0p, ErrRange},
+ {"-0x1fffffffffffff.8p+971i", inf0m, ErrRange},
+ {"+0x1.fffffffffffff8p1023+0x1.fffffffffffff8p1023i", infpp, ErrRange},
+ {"+0x1.fffffffffffff8p1023-0x1.fffffffffffff8p1023i", infpm, ErrRange},
+ {"-0x1fffffffffffff.8p+971+0x1fffffffffffff.8p+971i", infmp, ErrRange},
+ {"-0x1fffffffffffff8p+967-0x1fffffffffffff8p+967i", infmm, ErrRange},
+ // a little too large
+ {"1e308+1e308i", 1e+308 + 1e+308i, nil},
+ {"2e308+2e308i", infpp, ErrRange},
+ {"1e309+1e309i", infpp, ErrRange},
+ {"0x1p1025+0x1p1025i", infpp, ErrRange},
+ {"2e308", infp0, ErrRange},
+ {"1e309", infp0, ErrRange},
+ {"0x1p1025", infp0, ErrRange},
+ {"2e308i", inf0p, ErrRange},
+ {"1e309i", inf0p, ErrRange},
+ {"0x1p1025i", inf0p, ErrRange},
+ // way too large
+ {"+1e310+1e310i", infpp, ErrRange},
+ {"+1e310-1e310i", infpm, ErrRange},
+ {"-1e310+1e310i", infmp, ErrRange},
+ {"-1e310-1e310i", infmm, ErrRange},
+ // under/overflow exponent
+ {"1e-4294967296", 0, nil},
+ {"1e-4294967296i", 0, nil},
+ {"1e-4294967296+1i", 1i, nil},
+ {"1+1e-4294967296i", 1, nil},
+ {"1e-4294967296+1e-4294967296i", 0, nil},
+ {"1e+4294967296", infp0, ErrRange},
+ {"1e+4294967296i", inf0p, ErrRange},
+ {"1e+4294967296+1e+4294967296i", infpp, ErrRange},
+ {"1e+4294967296-1e+4294967296i", infpm, ErrRange},
+ }
+ for _, tt := range tests {
+ tt := tt // for capture in Run closures below
+ if tt.err != nil {
+ tt.err = &NumError{Func: "ParseComplex", Num: tt.in, Err: tt.err}
+ }
+ t.Run(tt.in, func(t *testing.T) {
+ got, err := ParseComplex(tt.in, 128)
+ if !reflect.DeepEqual(err, tt.err) {
+ t.Fatalf("ParseComplex(%q, 128) = %v, %v want %v, %v", tt.in, got, err, tt.out, tt.err)
+ }
+ if !(cmplx.IsNaN(tt.out) && cmplx.IsNaN(got)) && got != tt.out {
+ t.Fatalf("ParseComplex(%q, 128) = %v, %v want %v, %v", tt.in, got, err, tt.out, tt.err)
+ }
+ })
+ }
+}