all: use more maps and slices APIs from Go 1.23

These were found by looking for common suspects such as make
calls using the length of another slice or map,
or calls to slices.Sort after a simple loop.

Done as a separate commit, as none of these were already marked as
TODOs so they require slightly more scrutiny to check for mistakes.

Signed-off-by: Daniel Martí <[email protected]>
Change-Id: I1da3c8dcbb58efa16b1d616a244b0a4c6262de84
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1208912
TryBot-Result: CUEcueckoo <[email protected]>
Reviewed-by: Roger Peppe <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>

Author: mvdan

cue/build/import.go

@@ -15,6 +15,7 @@
 package build
 
 import (
+	"maps"
 	"slices"
 	"strconv"
 
@@ -143,11 +144,7 @@ func (inst *Instance) complete() errors.Error {
 			deps[path] = p1
 		}
 	}
-	inst.Deps = make([]string, 0, len(deps))
-	for dep := range deps {
-		inst.Deps = append(inst.Deps, dep)
-	}
-	slices.Sort(inst.Deps)
+	inst.Deps = slices.Sorted(maps.Keys(deps))
 
 	for _, dep := range inst.Deps {
 		p1 := deps[dep]

cue/load/loader_common.go

@@ -16,6 +16,7 @@ package load
 
 import (
 	"cmp"
+	"maps"
 	pathpkg "path"
 	"path/filepath"
 	"slices"
@@ -146,7 +147,7 @@ func (fp *fileProcessor) finalize(p *build.Instance) errors.Error {
 		return fp.err
 	}
 
-	p.ImportPaths, _ = cleanImports(fp.imported)
+	p.ImportPaths = slices.Sorted(maps.Keys(fp.imported))
 
 	return nil
 }
@@ -344,15 +345,6 @@ func (fp *fileProcessor) add(root string, file *build.File, mode importMode) {
 	}
 }
 
-func cleanImports(m map[string][]token.Pos) ([]string, map[string][]token.Pos) {
-	all := make([]string, 0, len(m))
-	for path := range m {
-		all = append(all, path)
-	}
-	slices.Sort(all)
-	return all, m
-}
-
 // isLocalImport reports whether the import path is
 // a local import path, like ".", "..", "./foo", or "../foo".
 func isLocalImport(path string) bool {

encoding/jsonschema/external_test.go

@@ -18,6 +18,7 @@ import (
 	stdjson "encoding/json"
 	"fmt"
 	"io"
+	"maps"
 	"os"
 	"path"
 	"slices"
@@ -55,7 +56,7 @@ func TestExternal(t *testing.T) {
 	// by the end.
 	cuetdtest.SmallMatrix.Run(t, "tests", func(t *testing.T, m *cuetdtest.M) {
 		// Run tests in deterministic order so we get some consistency between runs.
-		for _, filename := range sortedKeys(tests) {
+		for _, filename := range slices.Sorted(maps.Keys(tests)) {
 			schemas := tests[filename]
 			t.Run(testName(filename), func(t *testing.T) {
 				for _, s := range schemas {
@@ -255,15 +256,6 @@ var extVersionToVersion = map[string]jsonschema.Version{
 	"draft-next":   jsonschema.VersionUnknown,
 }
 
-func sortedKeys[T any](m map[string]T) []string {
-	ks := make([]string, 0, len(m))
-	for k := range m {
-		ks = append(ks, k)
-	}
-	slices.Sort(ks)
-	return ks
-}
-
 func writeExternalTestStats(testDir string, tests map[string][]*externaltest.Schema) error {
 	outf, err := os.Create("external_teststats.txt")
 	if err != nil {

encoding/jsonschema/teststats.go

@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"io"
 	"log"
+	"maps"
 	"os"
 	"path"
 	"slices"
@@ -50,7 +51,7 @@ func main() {
 }
 
 func listFailures(outw io.Writer, version string, tests map[string][]*externaltest.Schema) {
-	for _, filename := range sortedKeys(tests) {
+	for _, filename := range slices.Sorted(maps.Keys(tests)) {
 		schemas := tests[filename]
 		for _, schema := range schemas {
 			if schema.Skip[version] != "" {
@@ -79,12 +80,3 @@ func testdataPos(p positioner) token.Position {
 	pp.Filename = path.Join(testDir, pp.Filename)
 	return pp
 }
-
-func sortedKeys[T any](m map[string]T) []string {
-	ks := make([]string, 0, len(m))
-	for k := range m {
-		ks = append(ks, k)
-	}
-	slices.Sort(ks)
-	return ks
-}

encoding/openapi/build.go

@@ -17,6 +17,7 @@ package openapi
 import (
 	"cmp"
 	"fmt"
+	"maps"
 	"math"
 	"path"
 	"regexp"
@@ -149,13 +150,7 @@ func schemas(g *Generator, inst cue.InstanceOrValue) (schemas *ast.StructLit, er
 		done = len(c.externalRefs)
 
 		// From now on, all references need to be expanded
-		external := []string{}
-		for k := range c.externalRefs {
-			external = append(external, k)
-		}
-		slices.Sort(external)
-
-		for _, k := range external {
+		for _, k := range slices.Sorted(maps.Keys(c.externalRefs)) {
 			ext := c.externalRefs[k]
 			c.instExt = ext.inst
 			sels := ext.path.Selectors()

internal/core/export/self_test.go

@@ -16,6 +16,7 @@ package export_test
 
 import (
 	"bytes"
+	"slices"
 	"strings"
 	"testing"
 
@@ -106,8 +107,7 @@ func buildFile(t *testing.T, r *cue.Context, b *build.Instance) cue.Value {
 // file.
 func patch(t *testing.T, r *cue.Context, orig *txtar.Archive, f *ast.File) cue.Value {
 	a := *orig
-	a.Files = make([]txtar.File, len(a.Files))
-	copy(a.Files, orig.Files)
+	a.Files = slices.Clone(orig.Files)
 
 	k := 0
 	for _, f := range a.Files {

internal/mod/modpkgload/pkgload.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"io/fs"
+	"maps"
 	"runtime"
 	"slices"
 	"strings"
@@ -311,11 +312,8 @@ func (pkgs *Packages) load(ctx context.Context, pkg *Package) {
 		}
 		return
 	}
-	imports := make([]string, 0, len(importsMap))
-	for imp := range importsMap {
-		imports = append(imports, imp)
-	}
-	slices.Sort(imports) // Make the algorithm deterministic for tests.
+	// Make the algorithm deterministic for tests.
+	imports := slices.Sorted(maps.Keys(importsMap))
 
 	pkg.imports = make([]*Package, 0, len(imports))
 	var importFlags Flags

internal/mod/mvs/mvs_test.go

@@ -6,6 +6,7 @@ package mvs
 
 import (
 	"fmt"
+	"maps"
 	"reflect"
 	"strings"
 	"testing"
@@ -527,10 +528,7 @@ func Test(t *testing.T) {
 				if err == nil {
 					// Copy the reqs map, but substitute the upgraded requirements in
 					// place of the target's original requirements.
-					upReqs := make(reqsMap, len(reqs))
-					for m, r := range reqs {
-						upReqs[m] = r
-					}
+					upReqs := maps.Clone(reqs)
 					upReqs[m(kf[1])] = list
 
 					list, err = Req(m(kf[1]), nil, upReqs)