clean up SetString (#168)

Updates #166

Signed-off-by: Eric Lagergren <[email protected]>

big.go

@@ -271,7 +271,7 @@ func (z *Big) xflow(exp int, over, neg bool) *Big {
 
 func (x *Big) isCompact() bool  { return x.compact != c.Inflated }
 func (x *Big) isInflated() bool { return !x.isCompact() }
-func (x *Big) isSpecial() bool  { return x.form&(inf|nan) != 0 }
+func (x *Big) isSpecial() bool  { return x.form&special != 0 }
 
 // isZero reports whether x is zero.
 //
@@ -1641,10 +1641,9 @@ func (z *Big) SetScale(scale int) *Big {
 // can be passed to SetString.
 var Regexp = regexp.MustCompile(`(?i)(([+-]?(\d+\.\d*|\.?\d+)([eE][+-]?\d+)?)|(inf(infinity)?))|([+-]?([sq]?nan\d*))`)
 
-// SetString sets z to the value of s, returning z and a bool
-// indicating success.
+// SetString sets z to the value of s and returns z.
 //
-// s must be a string in one of the following formats:
+// s must have one of the following formats:
 //
 // 	1.234
 // 	1234
@@ -1656,11 +1655,17 @@ var Regexp = regexp.MustCompile(`(?i)(([+-]?(\d+\.\d*|\.?\d+)([eE][+-]?\d+)?)|(i
 // 	qNaN
 // 	sNaN
 //
-// Each value may be preceded by an optional sign, "-" or "+".
-// "Inf" and "NaN" map to "+Inf" and "qNaN", respectively. NaN
-// values may have optional diagnostic information, represented
-// as trailing digits; for example, "NaN123". These digits are
-// otherwise ignored but are included for robustness.
+// Each format may be preceded by an optional sign, either "-" or
+// "+". By default, "Inf" and "NaN" map to "+Inf" and "qNaN",
+// respectively. NaN values may have optional diagnostic
+// information, represented as trailing digits; for example,
+// "NaN123".
+//
+// If s does not match one of the allowed formats, the
+// ConversionSyntax condition is set.
+//
+// SetString will only return (nil, false) if a library error
+// occurs. In general, it safe to ignore the bool result.
 func (z *Big) SetString(s string) (*Big, bool) {
 	if err := z.scan(strings.NewReader(s)); err != nil {
 		return nil, false

big_test.go

@@ -650,12 +650,10 @@ func TestExp(t *testing.T) {
 		{"8.5", "4914.768840299134375431373676347828585214799657921037598580285209797607458733169528371064981979491498670292533027962716306703436339854535231155132783610120401650762002683099021054602507219969322181366306285407097420610361642274475387237868040396608369229178064395794276613661196368533479681502003855009", 301, Inexact | Rounded},
 		{"-3.2111455189183169875200429E-37", "1.0000000000000000000000000", 26, Inexact | Rounded},
 	} {
-		var x Big
+		var z, x, r Big
 		x.SetString(tc.x)
-		var z Big
 		ctx := Context{Precision: tc.prec}
 		ctx.Exp(&z, &x)
-		var r Big
 		r.Context.Conditions |= tc.cond
 		r.SetString(tc.r)
 		if !equal(&r, &z) {
@@ -1005,14 +1003,14 @@ func TestBig_Round(t *testing.T) {
 		to  int
 		res string
 	}{
-		0: {"5.5", 1, "6"},
-		1: {"1.234", 2, "1.2"},
-		2: {"1", 1, "1"},
-		3: {"9.876", 0, "9.876"},
-		4: {"5.65", 2, "5.6"},
-		5: {"5.0002", 2, "5"},
-		6: {"0.000158674", 6, "0.000158674"},
-		7: {"1.58089722856961873690377135139876745465351534188711107066818e+12288", 50, "1.5808972285696187369037713513987674546535153418871e+12288"},
+		{"5.5", 1, "6"},
+		{"1.234", 2, "1.2"},
+		{"1", 1, "1"},
+		{"9.876", 0, "9.876"},
+		{"5.65", 2, "5.6"},
+		{"5.0002", 2, "5"},
+		{"0.000158674", 6, "0.000158674"},
+		{"1.58089722856961873690377135139876745465351534188711107066818e+12288", 50, "1.5808972285696187369037713513987674546535153418871e+12288"},
 	} {
 		bd, _ := new(Big).SetString(test.v)
 		r, _ := new(Big).SetString(test.res)
@@ -1026,7 +1024,7 @@ got   : %q
 }
 
 func TestBig_Scan(t *testing.T) {
-	// TODO(eric): write this test
+	// TODO(eric): this
 }
 
 func TestBig_SetFloat64(t *testing.T) {

context.go

@@ -43,11 +43,12 @@ type Context struct {
 	//
 	Precision int
 
-	// Traps are a set of exceptional conditions that should result in an error.
+	// Traps are a set of exceptional conditions that should
+	// result in an error.
 	Traps Condition
 
-	// Conditions are a set of the most recent exceptional conditions to occur
-	// during an operation.
+	// Conditions are a set of the most recent exceptional
+	// conditions to occur during an operation.
 	Conditions Condition
 
 	// RoundingMode determines how a decimal is rounded.

pytables_test.go

@@ -264,7 +264,7 @@ func (c *scase) Assert(got, want interface{}) {
 	c.t.Helper()
 
 	if !reflect.DeepEqual(got, want) {
-		c.t.Fatalf(`#%d: %s
+		c.t.Errorf(`#%d: %s
 wanted: %v
 got   : %v
 `, c.i, c.c.ShortString(22), want, got)
@@ -276,7 +276,7 @@ func (c *scase) Check(z *Big) {
 
 	r := c.R()
 	if !pytablesEqual(z, r) {
-		c.t.Fatalf(`#%d: %s
+		c.t.Errorf(`#%d: %s
 wanted: %q (%s:%d)
 got   : %q (%s:%d)
 `,