lib/tabula: realign struct for better size allocation

The realignment reduce the cost of the following struct,

* Claset: from 136 to 120 bytes (-16)
* Column: from 64 to 48 bytes (-16)
* Dataset: from 40 to 32 bytes (-8)

While at it, fix linter warnings due to unused parameters in test.

4 files changed, 27 insertions, 18 deletions

diff --git a/lib/tabula/claset.go b/lib/tabula/claset.go
index 406037d6..8bb4a9ae 100644
--- a/lib/tabula/claset.go
+++ b/lib/tabula/claset.go
@@ -14,20 +14,23 @@ import (
 
 // Claset define a dataset with class attribute.
 type Claset struct {
-	// Dataset embedded, for implementing the dataset interface.
-	Dataset
-	// ClassIndex contain index for target classification in columns.
-	ClassIndex int `json:"ClassIndex"`
+	// major contain the name of majority class in dataset.
+	major string
+
+	// minor contain the name of minority class in dataset.
+	minor string
 
 	// vs contain a copy of value space.
 	vs []string
+
 	// counts number of value space in current set.
 	counts []int
 
-	// major contain the name of majority class in dataset.
-	major string
-	// minor contain the name of minority class in dataset.
-	minor string
+	// Dataset embedded, for implementing the dataset interface.
+	Dataset
+
+	// ClassIndex contain index for target classification in columns.
+	ClassIndex int `json:"ClassIndex"`
 }
 
 // NewClaset create and return new Claset object.
diff --git a/lib/tabula/column.go b/lib/tabula/column.go
index b59a53e5..091d6ad5 100644
--- a/lib/tabula/column.go
+++ b/lib/tabula/column.go
@@ -12,15 +12,19 @@ import (
 type Column struct {
 	// Name of column. String identifier for the column.
 	Name string
+
+	// ValueSpace contain the possible value in records
+	ValueSpace []string
+
+	// Records contain column data.
+	Records Records
+
 	// Type of column. All record in column have the same type.
 	Type int
+
 	// Flag additional attribute that can be set to mark some value on this
 	// column
 	Flag int
-	// ValueSpace contain the possible value in records
-	ValueSpace []string
-	// Records contain column data.
-	Records Records
 }
 
 // NewColumn return new column with type and name.
diff --git a/lib/tabula/dataset.go b/lib/tabula/dataset.go
index bd0bfca2..dfcc11be 100644
--- a/lib/tabula/dataset.go
+++ b/lib/tabula/dataset.go
@@ -33,12 +33,14 @@ var (
 // Dataset contain the data, mode of saved data, number of columns and rows in
 // data.
 type Dataset struct {
-	// Mode define the numeric value of output mode.
-	Mode int
 	// Columns is input data that has been parsed.
 	Columns Columns
+
 	// Rows is input data that has been parsed.
 	Rows Rows
+
+	// Mode define the numeric value of output mode.
+	Mode int
 }
 
 // NewDataset create new dataset, use the mode to initialize the dataset.
diff --git a/lib/tabula/dataset_test.go b/lib/tabula/dataset_test.go
index 68598deb..9c45ce81 100644
--- a/lib/tabula/dataset_test.go
+++ b/lib/tabula/dataset_test.go
@@ -82,21 +82,21 @@ func createDataset(t *testing.T) (dataset *Dataset) {
 	return
 }
 
-func DatasetStringJoinByIndex(t *testing.T, dataset [][]string, indis []int) (res string) {
+func DatasetStringJoinByIndex(_ *testing.T, dataset [][]string, indis []int) (res string) {
 	for x := range indis {
 		res += fmt.Sprint("&", dataset[indis[x]])
 	}
 	return res
 }
 
-func DatasetRowsJoin(t *testing.T) (s string) {
+func DatasetRowsJoin(_ *testing.T) (s string) {
 	for x := range datasetRows {
 		s += fmt.Sprint("&", datasetRows[x])
 	}
 	return
 }
 
-func DatasetColumnsJoin(t *testing.T) (s string) {
+func DatasetColumnsJoin(_ *testing.T) (s string) {
 	for x := range datasetCols {
 		s += fmt.Sprint(datasetCols[x])
 	}
@@ -205,7 +205,7 @@ func TestModeRowsPushColumn(t *testing.T) {
 	test.Assert(t, "", exp, got)
 
 	// Check columns
-	exp = "[{int 1 0 [] []} {real 2 0 [] []} {string 0 0 [] []}]"
+	exp = `[{int [] [] 1 0} {real [] [] 2 0} {string [] [] 0 0}]`
 	got = fmt.Sprint(dataset.Columns)
 
 	test.Assert(t, "", exp, got)