apd: drop github.com/pkg/errors

Fixes cockroachdb#123.

Now that the stdlib's "errors" package supports wrapping, use it to
eliminate a dependency on "github.com/pkg/errors".

Picks up the "lib/pq" test dependency. Bump `go.mod` to `go 1.17` to
allow users of the library to prune this dependency
(https://go.dev/ref/mod#graph-pruning).

condition.go

@@ -15,9 +15,9 @@
 package apd
 
 import (
+	"errors"
+	"fmt"
 	"strings"
-
-	"github.com/pkg/errors"
 )
 
 // Condition holds condition flags.
@@ -143,7 +143,7 @@ func (r Condition) String() string {
 		case Clamped:
 			s = "clamped"
 		default:
-			panic(errors.Errorf("unknown condition %d", i))
+			panic(fmt.Errorf("unknown condition %d", i))
 		}
 		names = append(names, s)
 	}

context.go

@@ -15,9 +15,9 @@
 package apd
 
 import (
+	"errors"
+	"fmt"
 	"math"
-
-	"github.com/pkg/errors"
 )
 
 // Context maintains options for Decimal operations. It can safely be used
@@ -116,7 +116,7 @@ func (c *Context) setAsNaN(d *Decimal, x, y *Decimal) (Condition, error) {
 	} else if y != nil && y.Form == NaN {
 		nan = y
 	} else {
-		return 0, errors.Errorf("no NaN value found; was shouldSetAsNaN called?")
+		return 0, errors.New("no NaN value found; was shouldSetAsNaN called?")
 	}
 	d.Set(nan)
 	var res Condition
@@ -149,7 +149,7 @@ func (c *Context) add(d, x, y *Decimal, subtract bool) (Condition, error) {
 	var tmp BigInt
 	a, b, s, err := upscale(x, y, &tmp)
 	if err != nil {
-		return 0, errors.Wrap(err, "add")
+		return 0, fmt.Errorf("add: %w", err)
 	}
 	d.Negative = xn
 	if xn == yn {
@@ -379,7 +379,7 @@ func (c *Context) QuoInteger(d, x, y *Decimal) (Condition, error) {
 	var tmp BigInt
 	a, b, _, err := upscale(x, y, &tmp)
 	if err != nil {
-		return 0, errors.Wrap(err, "QuoInteger")
+		return 0, fmt.Errorf("QuoInteger: %w", err)
 	}
 	d.Coeff.Quo(a, b)
 	d.Form = Finite
@@ -421,7 +421,7 @@ func (c *Context) Rem(d, x, y *Decimal) (Condition, error) {
 	var tmp1 BigInt
 	a, b, s, err := upscale(x, y, &tmp1)
 	if err != nil {
-		return 0, errors.Wrap(err, "Rem")
+		return 0, fmt.Errorf("Rem: %w", err)
 	}
 	var tmp2 BigInt
 	tmp2.QuoRem(a, b, &d.Coeff)
@@ -858,7 +858,7 @@ func (c *Context) Log10(d, x *Decimal) (Condition, error) {
 	var z Decimal
 	_, err := nc.Ln(&z, x)
 	if err != nil {
-		return 0, errors.Wrap(err, "ln")
+		return 0, fmt.Errorf("ln: %w", err)
 	}
 	nc.Precision = c.Precision
 
@@ -942,7 +942,7 @@ func (c *Context) Exp(d, x *Decimal) (Condition, error) {
 	nc := c.WithPrecision(cp)
 	nc.Rounding = RoundHalfEven
 	if _, err := nc.Quo(&r, x, &k); err != nil {
-		return 0, errors.Wrap(err, "Quo")
+		return 0, fmt.Errorf("Quo: %w", err)
 	}
 	var ra Decimal
 	ra.Abs(&r)
@@ -951,7 +951,7 @@ func (c *Context) Exp(d, x *Decimal) (Condition, error) {
 	// Stage 3
 	rf, err := ra.Float64()
 	if err != nil {
-		return 0, errors.Wrap(err, "r.Float64")
+		return 0, fmt.Errorf("r.Float64: %w", err)
 	}
 	pf := float64(p)
 	nf := math.Ceil((1.435*pf - 1.182) / math.Log10(pf/rf))
@@ -983,11 +983,11 @@ func (c *Context) Exp(d, x *Decimal) (Condition, error) {
 	var tmpE BigInt
 	ki, err := exp10(int64(t), &tmpE)
 	if err != nil {
-		return 0, errors.Wrap(err, "ki")
+		return 0, fmt.Errorf("ki: %w", err)
 	}
 	ires, err := nc.integerPower(d, &sum, ki)
 	if err != nil {
-		return 0, errors.Wrap(err, "integer power")
+		return 0, fmt.Errorf("integer power: %w", err)
 	}
 	res |= ires
 	nc.Precision = c.Precision

decimal.go

@@ -15,12 +15,13 @@
 package apd
 
 import (
+	"errors"
+	"fmt"
 	"strconv"
 	"strings"
 	"unsafe"
 
 	"database/sql/driver"
-	"github.com/pkg/errors"
 )
 
 // Decimal is an arbitrary-precision decimal. Its value is:
@@ -113,7 +114,7 @@ func (d *Decimal) setString(c *Context, s string) (Condition, error) {
 	// Until there are no parse errors, leave as NaN.
 	d.Form = NaN
 	if strings.HasPrefix(s, "-") || strings.HasPrefix(s, "+") {
-		return 0, errors.Errorf("could not parse: %s", orig)
+		return 0, fmt.Errorf("could not parse: %s", orig)
 	}
 	switch s {
 	case "infinity", "inf":
@@ -135,7 +136,7 @@ func (d *Decimal) setString(c *Context, s string) (Condition, error) {
 			// We ignore these digits, but must verify them.
 			_, err := strconv.ParseUint(s, 10, 64)
 			if err != nil {
-				return 0, errors.Wrapf(err, "parse payload: %s", s)
+				return 0, fmt.Errorf("parse payload: %s: %w", s, err)
 			}
 		}
 		return 0, nil
@@ -145,7 +146,7 @@ func (d *Decimal) setString(c *Context, s string) (Condition, error) {
 	if i := strings.IndexByte(s, 'e'); i >= 0 {
 		exp, err := strconv.ParseInt(s[i+1:], 10, 32)
 		if err != nil {
-			return 0, errors.Wrapf(err, "parse exponent: %s", s[i+1:])
+			return 0, fmt.Errorf("parse exponent: %s: %w", s[i+1:], err)
 		}
 		exps = append(exps, exp)
 		s = s[:i]
@@ -156,7 +157,7 @@ func (d *Decimal) setString(c *Context, s string) (Condition, error) {
 		s = s[:i] + s[i+1:]
 	}
 	if _, ok := d.Coeff.SetString(s, 10); !ok {
-		return 0, errors.Errorf("parse mantissa: %s", s)
+		return 0, fmt.Errorf("parse mantissa: %s", s)
 	}
 	// No parse errors, can now flag as finite.
 	d.Form = Finite
@@ -248,19 +249,19 @@ func (d *Decimal) SetFloat64(f float64) (*Decimal, error) {
 // int64, an error is returned.
 func (d *Decimal) Int64() (int64, error) {
 	if d.Form != Finite {
-		return 0, errors.Errorf("%s is not finite", d.String())
+		return 0, fmt.Errorf("%s is not finite", d.String())
 	}
 	var integ, frac Decimal
 	d.Modf(&integ, &frac)
 	if !frac.IsZero() {
-		return 0, errors.Errorf("%s: has fractional part", d.String())
+		return 0, fmt.Errorf("%s: has fractional part", d.String())
 	}
 	var ed ErrDecimal
 	if integ.Cmp(decimalMaxInt64) > 0 {
-		return 0, errors.Errorf("%s: greater than max int64", d.String())
+		return 0, fmt.Errorf("%s: greater than max int64", d.String())
 	}
 	if integ.Cmp(decimalMinInt64) < 0 {
-		return 0, errors.Errorf("%s: less than min int64", d.String())
+		return 0, fmt.Errorf("%s: less than min int64", d.String())
 	}
 	if err := ed.Err(); err != nil {
 		return 0, err
@@ -781,7 +782,7 @@ func (d *Decimal) Scan(src interface{}) error {
 		_, err := d.SetFloat64(src)
 		return err
 	default:
-		return errors.Errorf("could not convert %T to Decimal", src)
+		return fmt.Errorf("could not convert %T to Decimal", src)
 	}
 }
 

go.mod

@@ -1,5 +1,5 @@
 module github.com/cockroachdb/apd/v3
 
-go 1.13
+go 1.17
 
-require github.com/pkg/errors v0.8.0
+require github.com/lib/pq v1.10.7

go.sum

@@ -1,2 +1,2 @@
-github.com/pkg/errors v0.8.0 h1:WdK/asTD0HN+q6hsWO3/vpuAkAr+tw6aNJNDFFf0+qw=
-github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/lib/pq v1.10.7 h1:p7ZhMD+KsSRozJr34udlUrhboJwWAgCg34+/ZZNvZZw=
+github.com/lib/pq v1.10.7/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=

loop.go

@@ -7,9 +7,8 @@
 package apd
 
 import (
+	"fmt"
 	"math"
-
-	"github.com/pkg/errors"
 )
 
 type loop struct {
@@ -79,7 +78,7 @@ func (l *loop) done(z *Decimal) (bool, error) {
 	}
 	l.i++
 	if l.i == l.maxIterations {
-		return false, errors.Errorf(
+		return false, fmt.Errorf(
 			"%s %s: did not converge after %d iterations; prev,last result %s,%s delta %s precision: %d",
 			l.name, l.arg.String(), l.maxIterations, z.String(), l.prevZ.String(), l.delta.String(), l.precision,
 		)