Performance and style fixes (#1981)

* Switch to integer ranges in for loops

Signed-off-by: Stephen Kitt <steve@sk2.org>

* Switch to slices functions where appropriate

A number of utility functions can be replaced outright; since Miller
can technically be used as a library, these are deprecated rather than
removed. go:fix directives ensure that they can be replaced
automatically.

Signed-off-by: Stephen Kitt <steve@sk2.org>

* Switch to reflect.TypeFor

This is slightly more efficient than TypeOf when the type is known at
compile time.

Signed-off-by: Stephen Kitt <steve@sk2.org>

* Switch to strings.SplitSeq instead of strings.Split

SplitSeq results in fewer allocations.

Signed-off-by: Stephen Kitt <steve@sk2.org>

* Drop obsolete build directives

Signed-off-by: Stephen Kitt <steve@sk2.org>

* Use min/max instead of explicit comparisons

Signed-off-by: Stephen Kitt <steve@sk2.org>

* Append slices instead of looping

Signed-off-by: Stephen Kitt <steve@sk2.org>

---------

Signed-off-by: Stephen Kitt <steve@sk2.org>

Author: skitt

pkg/auxents/hex.go

@@ -108,7 +108,7 @@ func hexDumpFile(istream *os.File, doRaw bool) {
 		}
 
 		// Print hex payload
-		for i := 0; i < bufferSize; i++ {
+		for i := range bufferSize {
 			if i < numBytesRead {
 				fmt.Printf("%02x ", buffer[i])
 			} else {
@@ -125,7 +125,7 @@ func hexDumpFile(istream *os.File, doRaw bool) {
 		if !doRaw {
 			fmt.Printf("|")
 
-			for i := 0; i < numBytesRead; i++ {
+			for i := range numBytesRead {
 				if buffer[i] >= 0x20 && buffer[i] <= 0x7e {
 					fmt.Printf("%c", buffer[i])
 				} else {

pkg/bifs/stats.go

@@ -458,7 +458,7 @@ func BIF_sort_collection(collection *mlrval.Mlrval) *mlrval.Mlrval {
 		arrayval := collection.AcquireArrayValue()
 		n := len(arrayval)
 		array = make([]*mlrval.Mlrval, n)
-		for i := 0; i < n; i++ {
+		for i := range n {
 			array[i] = arrayval[i].Copy()
 		}
 	} else {

pkg/bifs/stats_test.go

@@ -11,7 +11,7 @@ import (
 
 func stats_test_array(n int) *mlrval.Mlrval {
 	a := make([]*mlrval.Mlrval, n)
-	for i := 0; i < n; i++ {
+	for i := range n {
 		a[i] = mlrval.FromInt(int64(i))
 	}
 	return mlrval.FromArray(a)
@@ -20,7 +20,7 @@ func stats_test_array(n int) *mlrval.Mlrval {
 func array_to_map_for_test(a *mlrval.Mlrval) *mlrval.Mlrval {
 	array := a.AcquireArrayValue()
 	m := mlrval.NewMlrmap()
-	for i := 0; i < len(array); i++ {
+	for i := range array {
 		key := fmt.Sprint(i)
 		val := array[i]
 		m.PutCopy(key, val)
@@ -34,7 +34,7 @@ func TestBIF_count(t *testing.T) {
 	output := BIF_count(input)
 	assert.True(t, output.IsError())
 
-	for n := 0; n < 5; n++ {
+	for n := range 5 {
 		input = stats_test_array(n)
 		assert.True(t, mlrval.Equals(BIF_count(input), mlrval.FromInt(int64(n))))
 

pkg/cli/flag_types.go

@@ -37,6 +37,7 @@ package cli
 
 import (
 	"fmt"
+	"slices"
 	"sort"
 	"strings"
 
@@ -390,12 +391,7 @@ func (flag *Flag) Owns(input string) bool {
 	if flag.name == input {
 		return true
 	}
-	for _, name := range flag.altNames {
-		if name == input {
-			return true
-		}
-	}
-	return false
+	return slices.Contains(flag.altNames, input)
 }
 
 // Matches is like Owns but is for substring matching, for on-line help with

pkg/dsl/ast_print.go

@@ -57,7 +57,7 @@ func (node *ASTNode) Print() {
 // printAux is a recursion-helper for Print.
 func (node *ASTNode) printAux(depth int) {
 	// Indent
-	for i := 0; i < depth; i++ {
+	for range depth {
 		fmt.Print("    ")
 	}
 
@@ -83,14 +83,14 @@ func (node *ASTNode) PrintParex() {
 // printParexAux is a recursion-helper for PrintParex.
 func (node *ASTNode) printParexAux(depth int) {
 	if node.IsLeaf() {
-		for i := 0; i < depth; i++ {
+		for range depth {
 			fmt.Print("    ")
 		}
 		fmt.Println(node.Text())
 
 	} else if node.ChildrenAreAllLeaves() {
 		// E.g. (= sum 0) or (+ 1 2)
-		for i := 0; i < depth; i++ {
+		for range depth {
 			fmt.Print("    ")
 		}
 		fmt.Print("(")
@@ -104,7 +104,7 @@ func (node *ASTNode) printParexAux(depth int) {
 
 	} else {
 		// Parent and opening parenthesis on first line
-		for i := 0; i < depth; i++ {
+		for range depth {
 			fmt.Print("    ")
 		}
 		fmt.Print("(")
@@ -116,7 +116,7 @@ func (node *ASTNode) printParexAux(depth int) {
 		}
 
 		// Closing parenthesis on last line
-		for i := 0; i < depth; i++ {
+		for range depth {
 			fmt.Print("    ")
 		}
 		fmt.Println(")")

pkg/dsl/cst/hofs.go

@@ -695,7 +695,7 @@ func sortM(
 
 	// Make a new map with entries in the new sort order.
 	outmap := mlrval.NewMlrmap()
-	for i := int64(0); i < n; i++ {
+	for i := range n {
 		entry := entries[i]
 		outmap.PutCopy(entry.Key, entry.Value)
 	}

pkg/input/record_reader_csv.go

@@ -229,7 +229,7 @@ func (reader *RecordReaderCSV) getRecordBatch(
 		if reader.header == nil { // implicit CSV header
 			n := len(csvRecord)
 			reader.header = make([]string, n)
-			for i := 0; i < n; i++ {
+			for i := range n {
 				reader.header[i] = strconv.Itoa(i + 1)
 			}
 		}
@@ -240,7 +240,7 @@ func (reader *RecordReaderCSV) getRecordBatch(
 		nd := int64(len(csvRecord))
 
 		if nh == nd {
-			for i := int64(0); i < nh; i++ {
+			for i := range nh {
 				key := reader.header[i]
 				value := mlrval.FromDeferredType(csvRecord[i])
 				_, err := record.PutReferenceMaybeDedupe(key, value, dedupeFieldNames)

pkg/input/record_reader_csvlite.go

@@ -332,7 +332,7 @@ func getRecordBatchImplicitCSVHeader(
 		if reader.headerStrings == nil {
 			n := len(fields)
 			reader.headerStrings = make([]string, n)
-			for i := 0; i < n; i++ {
+			for i := range n {
 				reader.headerStrings[i] = strconv.Itoa(i + 1)
 			}
 		} else {

pkg/input/record_reader_json.go

@@ -283,7 +283,7 @@ func (bsr *JSONCommentEnabledReader) populateFromLine(p []byte) int {
 		numBytesWritten = len(bsr.lineBytes)
 		bsr.lineBytes = nil
 	} else {
-		for i := 0; i < len(p); i++ {
+		for i := range p {
 			p[i] = bsr.lineBytes[i]
 		}
 		numBytesWritten = len(p)

pkg/input/record_reader_pprint.go

@@ -367,7 +367,7 @@ func getRecordBatchImplicitPprintHeader(
 		if reader.headerStrings == nil {
 			n := len(fields)
 			reader.headerStrings = make([]string, n)
-			for i := 0; i < n; i++ {
+			for i := range n {
 				reader.headerStrings[i] = strconv.Itoa(i + 1)
 			}
 		} else {