decimal: implement Decimal.Scan, Decimal.Value methods

* decimal: implement Decimal.Scan, Decimal.Value methods * decimal: improve Decimal.Scan coverage
govalues · Aug 19, 2023 · 9ad2f20 · 9ad2f20
1 parent e908700
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diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
@@ -54,26 +54,26 @@ jobs:
       uses: actions/checkout@v3
 
     - name: Run fuzzing for string conversion
-      run: go test -fuzztime 20s -fuzz ^FuzzDecimal_String_StringVsParse$ github.com/govalues/decimal
+      run: go test -fuzztime 20s -fuzz ^FuzzDecimalString$ github.com/govalues/decimal
 
     - name: Run fuzzing for float64 conversion
-      run: go test -fuzztime 20s -fuzz ^FuzzDecimal_Float64_Float64VsNew$ github.com/govalues/decimal
+      run: go test -fuzztime 20s -fuzz ^FuzzDecimalFloat64$ github.com/govalues/decimal
 
     - name: Run fuzzing for int64 conversion
-      run: go test -fuzztime 20s -fuzz ^FuzzDecimal_Int64_Int64VsNew$ github.com/govalues/decimal
+      run: go test -fuzztime 20s -fuzz ^FuzzDecimalInt64$ github.com/govalues/decimal
 
     - name: Run fuzzing for addition
-      run: go test -fuzztime 20s -fuzz ^FuzzDecimal_Add_FintVsSint$ github.com/govalues/decimal
+      run: go test -fuzztime 20s -fuzz ^FuzzDecimalAdd$ github.com/govalues/decimal
 
     - name: Run fuzzing for multiplication
-      run: go test -fuzztime 20s -fuzz ^FuzzDecimal_Mul_FintVsSint$ github.com/govalues/decimal
+      run: go test -fuzztime 20s -fuzz ^FuzzDecimalMul$ github.com/govalues/decimal
 
     - name: Run fuzzing for fused multiply-addidtion
-      run: go test -fuzztime 40s -fuzz ^FuzzDecimal_FMA_FintVsSint$ github.com/govalues/decimal
+      run: go test -fuzztime 40s -fuzz ^FuzzDecimalFMA$ github.com/govalues/decimal
 
     - name: Run fuzzing for division
-      run: go test -fuzztime 20s -fuzz ^FuzzDecimal_Quo_FintVsSint$ github.com/govalues/decimal
+      run: go test -fuzztime 20s -fuzz ^FuzzDecimalQuo$ github.com/govalues/decimal
 
     - name: Run fuzzing for comparison
-      run: go test -fuzztime 20s -fuzz ^FuzzDecimal_Cmp_FintVsSint$ github.com/govalues/decimal
+      run: go test -fuzztime 20s -fuzz ^FuzzDecimalCmp$ github.com/govalues/decimal
 
diff --git a/.golangci.yml b/.golangci.yml
@@ -8,7 +8,10 @@ linters:
     - goimports
     - govet
     - ineffassign
+    - godot
+    - gosec
     - misspell
+    - stylecheck
     - revive
     - staticcheck
     - typecheck

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,50 +1,61 @@
 # Changelog
 
+## [0.1.6] - 2023-08-19
+
+### Added
+
+- Implemented `Decimal.Scan` and `Decimal.Value`.
+
+### Changed
+
+- `Decimal.CopySign` treats 0 as a positive.
+- Enabled `gosec`, `godot`, and `stylecheck` linters.
+
 ## [0.1.5] - 2023-08-12
 
 ### Added
 
-- Implemented NewFromFloat64 method.
+- Implemented `NewFromFloat64` method.
 - Added fuzzing job to continuous integration.
 
 ### Changed
 
-- NewFromInt64 can round to nearest if coefficient is too large.
+- `NewFromInt64` can round to nearest if coefficient is too large.
 
 ## [0.1.4] - 2023-08-04
 
 ### Changed
 
-- Implemented NewFromInt64 method.
+- Implemented `NewFromInt64` method.
 
 ## [0.1.3] - 2023-08-03
 
 ### Changed
 
-- Implemented scale argument for Decimal.Int64 method.
+- Implemented scale argument for `Decimal.Int64` method.
 
 ## [0.1.2] - 2023-06-17
 
 ### Changed
 
-- Rescale, ParseExact, MulExact, AddExact, FMAExact, and QuoExact methods
+- `Rescale`, `ParseExact`, `MulExact`, `AddExact`, `FMAExact`, and `QuoExact` methods
   return error if scale is out of range.
 
 ## [0.1.1] - 2023-06-10
 
 ### Changed
 
-- New method returns error if scale is out of range.
+- `New` method returns error if scale is out of range.
 
 ## [0.1.0] - 2023-06-03
 
 ### Changed
 
 - All methods now return errors, instead of panicking.
-- Implemented Decimal.Pad method.
-- Implemented Decimal.PowExact method.
-- Renamed Decimal.Round to Decimal.Rescale.
-- Renamed Decimal.Reduce to Decimal.Trim.
+- Implemented `Decimal.Pad` method.
+- Implemented `Decimal.PowExact` method.
+- Renamed `Decimal.Round` to `Decimal.Rescale`.
+- Renamed `Decimal.Reduce` to `Decimal.Trim`.
 
 ## [0.0.13] - 2023-04-22
 
@@ -63,8 +74,8 @@
 
 ### Added
 
-- Implemented Decimal.Int64 method.
-- Implemented Decimal.Float64 method.
+- Implemented `Decimal.Int64` method.
+- Implemented `Decimal.Float64` method.
 
 ### Changed
 
@@ -81,35 +92,35 @@
 
 ### Added
 
-- Implemented Decimal.One method.
-- Implemented Decimal.Zero method.
+- Implemented `Decimal.One` method.
+- Implemented `Decimal.Zero` method.
 
 ### Changed
 
 - Reduced memory consumption.
-- Renamed Decimal.LessThanOne to Decimal.WithinOne.
+- Renamed `Decimal.LessThanOne` to `Decimal.WithinOne`.
 
 ### Deleted
 
-- Removed Decimal.WithScale.
+- Removed `Decimal.WithScale`.
 
 ## [0.0.8] - 2023-03-25
 
 ### Changed
 
-- Simplified Decimal.Quo method.
+- Simplified `Decimal.Quo` method.
 
 ## [0.0.7] - 2023-03-22
 
 ### Added
 
-- Implemented Decimal.CopySign method.
+- Implemented `Decimal.CopySign` method.
 
 ## [0.0.6] - 2023-03-21
 
 ### Added
 
-- Implemented Decimal.ULP method.
+- Implemented `Decimal.ULP` method.
 
 ## [0.0.5] - 2023-03-19
 
@@ -122,21 +133,21 @@
 
 ### Fixed
 
-- Fixed index out of range in Parse.
-- Rounding error in Decimal.Quo.
+- Fixed index out of range in `Parse`.
+- Rounding error in `Decimal.Quo`.
 
 ## [0.0.3] - 2023-03-18
 
 ### Changed
 
 - Removed errors from public API.
-- Renamed Decimal.Fma to Decimal.FMA.
+- Renamed `Decimal.Fma` to `Decimal.FMA`.
 
 ## [0.0.2] - 2023-03-13
 
 ### Added
 
-- Implemented Decimal.Fma.
+- Implemented `Decimal.Fma`.
 
 ## [0.0.1] - 2023-02-28
 

diff --git a/README.md b/README.md
@@ -3,8 +3,8 @@
 [![githubb]][github]
 [![codecovb]][codecov]
 [![goreportb]][goreport]
-[![licenseb]][license]
 [![godocb]][godoc]
+[![licenseb]][license]
 [![versionb]][version]
 
 Package decimal implements immutable decimal floating-point numbers for Go.
@@ -61,20 +61,20 @@ pkg: github.com/govalues/benchmarks
 cpu: AMD Ryzen 7 3700C  with Radeon Vega Mobile Gfx 
 ```
 
-| Test Case           | Expression           |   govalues | [cockroachdb] v3.1.2 | cockroachdb vs govalues | [shopspring] v1.3.1 | shopspring vs govalues |
-| ------------------- | -------------------- | ---------: | -------------------: | ----------------------: | ------------------: | ---------------------: |
-| Decimal_Add         | 2 + 3                |     15.54n |               47.39n |                +204.89% |             142.65n |               +817.66% |
-| Decimal_Mul         | 2 * 3                |     15.87n |               61.18n |                +285.51% |             136.60n |               +760.74% |
-| Decimal_QuoFinite   | 2 / 4                |     55.95n |              360.70n |                +544.74% |             654.45n |              +1069.81% |
-| Decimal_QuoInfinite | 2 / 3                |    570.10n |              936.40n |                 +64.27% |            2858.00n |               +401.36% |
-| Decimal_Pow         | 1.1^60               |      1.01µ |                3.06µ |                +202.92% |              20.09µ |              +1889.90% |
-| Parse               | 1                    |     17.35n |               88.44n |                +409.74% |             132.10n |               +661.38% |
-| Parse               | 123.456              |     36.75n |              220.15n |                +499.05% |             244.45n |               +565.17% |
-| Parse               | 123456789.1234567890 |    105.80n |              240.40n |                +127.33% |             496.00n |               +369.08% |
-| Decimal_String      | 1                    |      6.39n |               23.42n |                +266.32% |             237.95n |              +3622.62% |
-| Decimal_String      | 123.456              |     37.65n |               38.27n |                  +1.66% |             230.40n |               +512.03% |
-| Decimal_String      | 123456789.1234567890 |     74.95n |              189.70n |                +153.10% |             324.10n |               +332.42% |
-| **Geometric Mean**  |                      | **53.20n** |          **164.50n** |            **+209.17%** |         **462.80n** |           **+769.86%** |
+| Test Case           | Expression           | govalues | [cockroachdb] v3.2.0 | cockroachdb vs govalues | [shopspring] v1.3.1 | shopspring vs govalues |
+| ------------------- | -------------------- | -------: | -------------------: | ----------------------: | ------------------: | ---------------------: |
+| Decimal_Add         | 2 + 3                |   15.73n |               50.24n |                +219.39% |             141.85n |               +801.78% |
+| Decimal_Mul         | 2 * 3                |   15.67n |               67.34n |                +329.57% |             139.55n |               +790.27% |
+| Decimal_QuoFinite   | 2 / 4                |   61.08n |              371.35n |                +508.02% |             629.70n |               +931.03% |
+| Decimal_QuoInfinite | 2 / 3                |  560.80n |              946.10n |                 +68.69% |            2736.50n |               +387.92% |
+| Decimal_Pow         | 1.1^60               |    1.02µ |                2.89µ |                +182.58% |              20.08µ |              +1865.17% |
+| Parse               | 123456789.1234567890 |   99.16n |              219.15n |                +121.01% |             480.10n |               +384.17% |
+| Parse               | 123.456              |   37.41n |              203.80n |                +444.85% |             229.20n |               +512.75% |
+| Parse               | 1                    |   16.37n |               76.27n |                +365.91% |             128.90n |               +687.42% |
+| Decimal_String      | 123456789.1234567890 |   76.47n |              215.15n |                +181.35% |             329.35n |               +330.69% |
+| Decimal_String      | 123.456              |   40.86n |               70.52n |                 +72.59% |             222.10n |               +443.56% |
+| Decimal_String      | 1                    |    5.32n |               19.41n |                +264.88% |             192.75n |              +3523.46% |
+| **Geometric Mean**  |                      |   52.70n |              170.10n |                +222.71% |             445.40n |               +745.22% |
 
 The benchmark results shown in the table are provided for informational purposes only and may vary depending on your specific use case.
 

diff --git a/coefficient.go b/coefficient.go
@@ -35,20 +35,20 @@ var pow10 = [...]fint{
 }
 
 // add calculates x + y and checks overflow.
-func (x fint) add(y fint) (fint, bool) {
+func (x fint) add(y fint) (z fint, ok bool) {
 	if maxFint-x < y {
 		return 0, false
 	}
-	z := x + y
+	z = x + y
 	return z, true
 }
 
 // mul calculates x * y and checks overflow.
-func (x fint) mul(y fint) (fint, bool) {
+func (x fint) mul(y fint) (z fint, ok bool) {
 	if x == 0 || y == 0 {
 		return 0, true
 	}
-	z := x * y
+	z = x * y
 	if z/y != x {
 		return 0, false
 	}
@@ -59,11 +59,11 @@ func (x fint) mul(y fint) (fint, bool) {
 }
 
 // quo calculates x / y and checks overflow or inexact division.
-func (x fint) quo(y fint) (fint, bool) {
+func (x fint) quo(y fint) (z fint, ok bool) {
 	if y == 0 {
 		return 0, false
 	}
-	z := x / y
+	z = x / y
 	if y*z != x {
 		return 0, false
 	}
@@ -79,7 +79,7 @@ func (x fint) dist(y fint) fint {
 }
 
 // lsh (Left Shift) calculates x * 10^shift and checks overflow.
-func (x fint) lsh(shift int) (fint, bool) {
+func (x fint) lsh(shift int) (z fint, ok bool) {
 	// Special cases
 	switch {
 	case x == 0:
@@ -97,8 +97,8 @@ func (x fint) lsh(shift int) (fint, bool) {
 }
 
 // fsa (Fused Shift and Addition) calculates x * 10^shift + y and checks overflow.
-func (x fint) fsa(shift int, y byte) (fint, bool) {
-	z, ok := x.lsh(shift)
+func (x fint) fsa(shift int, y byte) (z fint, ok bool) {
+	z, ok = x.lsh(shift)
 	if !ok {
 		return 0, false
 	}
@@ -187,7 +187,7 @@ func (x fint) prec() int {
 	return left
 }
 
-// tzeroes returns number of trailing zeros in x
+// tzeroes returns number of trailing zeros in x.
 func (x fint) tzeros() int {
 	left, right := 1, x.prec()
 	for left < right {
@@ -362,7 +362,7 @@ func (z *sint) mul(x, y *sint) {
 	(*big.Int)(z).Mul((*big.Int)(x), (*big.Int)(y))
 }
 
-// quo calculates z = x / y
+// quo calculates z = x / y.
 func (z *sint) quo(x, y *sint) {
 	(*big.Int)(z).Quo((*big.Int)(x), (*big.Int)(y))
 }

diff --git a/coefficient_test.go b/coefficient_test.go
@@ -73,6 +73,8 @@ func TestFint_dist(t *testing.T) {
 		{20, 4, 16},
 		{20, 3, 17},
 		{maxFint, 2, 9_999_999_999_999_999_997},
+		{maxFint, 1, 9_999_999_999_999_999_998},
+		{maxFint, 0, maxFint},
 	}
 	for _, tt := range cases {
 		x, y := tt.x, tt.y