all: fix misuses of "a" vs "an"

Fixes the misuse of "a" vs "an", according to English grammatical
expectations and using https://www.a-or-an.com/

Change-Id: I53ac724070e3ff3d33c304483fe72c023c7cda47
Reviewed-on: https://go-review.googlesource.com/c/go/+/480536
Run-TryBot: shuang cui <imcusg@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>

src/archive/zip/struct.go

@@ -67,7 +67,7 @@ const (
 	//
 	// IDs 0..31 are reserved for official use by PKWARE.
 	// IDs above that range are defined by third-party vendors.
-	// Since ZIP lacked high precision timestamps (nor a official specification
+	// Since ZIP lacked high precision timestamps (nor an official specification
 	// of the timezone used for the date fields), many competing extra fields
 	// have been invented. Pervasive use effectively makes them "official".
 	//

src/bytes/buffer.go

@@ -109,7 +109,7 @@ func (b *Buffer) Reset() {
 	b.lastRead = opInvalid
 }
 
-// tryGrowByReslice is a inlineable version of grow for the fast-case where the
+// tryGrowByReslice is an inlineable version of grow for the fast-case where the
 // internal buffer only needs to be resliced.
 // It returns the index where bytes should be written and whether it succeeded.
 func (b *Buffer) tryGrowByReslice(n int) (int, bool) {

src/cmd/compile/internal/abt/avlint32.go

@@ -570,7 +570,7 @@ func (t *node32) lub(key int32, allow_eq bool) *node32 {
 			// t is too small, lub is to right.
 			t = t.right
 		} else {
-			// t is a upper bound, record it and seek a better one.
+			// t is an upper bound, record it and seek a better one.
 			best = t
 			t = t.left
 		}

src/cmd/compile/internal/ir/expr.go

@@ -380,7 +380,7 @@ func (n *InlinedCallExpr) SingleResult() Node {
 	return n.ReturnVars[0]
 }
 
-// A LogicalExpr is a expression X Op Y where Op is && or ||.
+// A LogicalExpr is an expression X Op Y where Op is && or ||.
 // It is separate from BinaryExpr to make room for statements
 // that must be executed before Y but after X.
 type LogicalExpr struct {

src/cmd/compile/internal/ir/val.go

@@ -92,7 +92,7 @@ func Int64Val(n Node) int64 {
 	return x
 }
 
-// Uint64Val returns n as an uint64.
+// Uint64Val returns n as a uint64.
 // n must be an integer or rune constant.
 func Uint64Val(n Node) uint64 {
 	if !IsConst(n, constant.Int) {

src/cmd/compile/internal/ssa/loopbce.go

@@ -93,7 +93,7 @@ func findIndVar(f *Func) []indVar {
 		var init *Value  // starting value
 		var limit *Value // ending value
 
-		// Check thet the control if it either ind </<= limit or limit </<= ind.
+		// Check that the control if it either ind </<= limit or limit </<= ind.
 		// TODO: Handle unsigned comparisons?
 		c := b.Controls[0]
 		inclusive := false
@@ -117,12 +117,12 @@ func findIndVar(f *Func) []indVar {
 			//     for i := len(n)-1; i >= 0; i--
 			init, inc, nxt = parseIndVar(limit)
 			if init == nil {
-				// No recognied induction variable on either operand
+				// No recognized induction variable on either operand
 				continue
 			}
 
 			// Ok, the arguments were reversed. Swap them, and remember that we're
-			// looking at a ind >/>= loop (so the induction must be decrementing).
+			// looking at an ind >/>= loop (so the induction must be decrementing).
 			ind, limit = limit, ind
 			less = false
 		}

src/cmd/compile/internal/ssa/op.go

@@ -372,7 +372,7 @@ const (
 	auxARM64BitField     // aux is an arm64 bitfield lsb and width packed into auxInt
 	auxS390XRotateParams // aux is a s390x rotate parameters object encoding start bit, end bit and rotate amount
 	auxS390XCCMask       // aux is a s390x 4-bit condition code mask
-	auxS390XCCMaskInt8   // aux is a s390x 4-bit condition code mask, auxInt is a int8 immediate
+	auxS390XCCMaskInt8   // aux is a s390x 4-bit condition code mask, auxInt is an int8 immediate
 	auxS390XCCMaskUint8  // aux is a s390x 4-bit condition code mask, auxInt is a uint8 immediate
 )
 

src/cmd/compile/internal/ssa/poset.go

@@ -56,7 +56,7 @@ const (
 )
 
 // posetUndo represents an undo pass to be performed.
-// It's an union of fields that can be used to store information,
+// It's a union of fields that can be used to store information,
 // and typ is the discriminant, that specifies which kind
 // of operation must be performed. Not all fields are always used.
 type posetUndo struct {

src/cmd/compile/internal/types/type.go

@@ -1345,7 +1345,7 @@ func (t *Type) IsUnsafePtr() bool {
 	return t.kind == TUNSAFEPTR
 }
 
-// IsUintptr reports whether t is an uintptr.
+// IsUintptr reports whether t is a uintptr.
 func (t *Type) IsUintptr() bool {
 	return t.kind == TUINTPTR
 }

src/cmd/compile/internal/walk/assign.go

@@ -609,7 +609,7 @@ func isAppendOfMake(n ir.Node) bool {
 	}
 
 	// y must be either an integer constant or the largest possible positive value
-	// of variable y needs to fit into an uint.
+	// of variable y needs to fit into a uint.
 
 	// typecheck made sure that constant arguments to make are not negative and fit into an int.
 
@@ -652,7 +652,7 @@ func isAppendOfMake(n ir.Node) bool {
 //	growslice will have done the clearing for us.
 
 func extendSlice(n *ir.CallExpr, init *ir.Nodes) ir.Node {
-	// isAppendOfMake made sure all possible positive values of l2 fit into an uint.
+	// isAppendOfMake made sure all possible positive values of l2 fit into a uint.
 	// The case of l2 overflow when converting from e.g. uint to int is handled by an explicit
 	// check of l2 < 0 at runtime which is generated below.
 	l2 := typecheck.Conv(n.Args[1].(*ir.MakeExpr).Len, types.Types[types.TINT])

src/cmd/internal/obj/ppc64/asm9.go

@@ -626,7 +626,7 @@ func addpad(pc, a int64, ctxt *obj.Link, cursym *obj.LSym) int {
 	return 0
 }
 
-// Get the implied register of a operand which doesn't specify one.  These show up
+// Get the implied register of an operand which doesn't specify one.  These show up
 // in handwritten asm like "MOVD R5, foosymbol" where a base register is not supplied,
 // or "MOVD R5, foo+10(SP) or pseudo-register is used.  The other common case is when
 // generating constants in register like "MOVD $constant, Rx".

src/cmd/internal/obj/riscv/obj.go

@@ -1691,7 +1691,7 @@ func instructionForProg(p *obj.Prog) *instruction {
 	return ins
 }
 
-// instructionsForOpImmediate returns the machine instructions for a immedate
+// instructionsForOpImmediate returns the machine instructions for an immediate
 // operand. The instruction is specified by as and the source register is
 // specified by rs, instead of the obj.Prog.
 func instructionsForOpImmediate(p *obj.Prog, as obj.As, rs int16) []*instruction {

src/cmd/internal/obj/wasm/wasmobj.go

@@ -232,7 +232,7 @@ func preprocess(ctxt *obj.Link, s *obj.LSym, newprog obj.ProgAlloc) {
 
 				// Offset is the location of the param on the Go stack (ie relative to sp).
 				// Because of our call convention, the parameters are located an additional 8 bytes
-				// from sp because we store the return address as a int64 at the bottom of the stack.
+				// from sp because we store the return address as an int64 at the bottom of the stack.
 				// Ie the stack looks like [return_addr, param3, param2, param1, etc]
 
 				// Ergo, we add 8 to the true byte offset of the param to skip the return address.

src/cmd/link/internal/ld/data.go

@@ -1677,7 +1677,7 @@ func (ctxt *Link) dodata(symGroupType []sym.SymKind) {
 	}
 }
 
-// allocateDataSectionForSym creates a new sym.Section into which a a
+// allocateDataSectionForSym creates a new sym.Section into which a
 // single symbol will be placed. Here "seg" is the segment into which
 // the section will go, "s" is the symbol to be placed into the new
 // section, and "rwx" contains permissions for the section.

src/cmd/link/internal/ld/xcoff.go

@@ -38,7 +38,7 @@ const (
 	// XCOFF binaries should normally have all its sections position-independent.
 	// However, this is not yet possible for .text because of some R_ADDR relocations
 	// inside RODATA symbols.
-	// .data and .bss are position-independent so their address start inside a unreachable
+	// .data and .bss are position-independent so their address start inside an unreachable
 	// segment during execution to force segfault if something is wrong.
 	XCOFFTEXTBASE = 0x100000000 // Start of text address
 	XCOFFDATABASE = 0x200000000 // Start of data address
@@ -875,7 +875,7 @@ func (f *xcoffFile) writeSymbolFunc(ctxt *Link, x loader.Sym) []xcoffSym {
 // put function used by genasmsym to write symbol table.
 func putaixsym(ctxt *Link, x loader.Sym, t SymbolType) {
 	// All XCOFF symbols generated by this GO symbols
-	// Can be a symbol entry or a auxiliary entry
+	// Can be a symbol entry or an auxiliary entry
 	syms := []xcoffSym{}
 
 	ldr := ctxt.loader
@@ -1329,7 +1329,7 @@ func (ctxt *Link) doxcoff() {
 			}
 
 			if ldr.SymType(s) == sym.STEXT {
-				// On AIX, a exported function must have two symbols:
+				// On AIX, an exported function must have two symbols:
 				// - a .text symbol which must start with a ".".
 				// - a .data symbol which is a function descriptor.
 				name := ldr.SymExtname(s)

src/cmd/link/internal/loadpe/ldpe.go

@@ -141,7 +141,7 @@ const (
 	// a jump to the loaded value.
 	CreateImportStubPltToken = -2
 
-	// When stored into the GOT value for a import symbol __imp_X this
+	// When stored into the GOT value for an import symbol __imp_X this
 	// token tells windynrelocsym to redirect references to the
 	// underlying DYNIMPORT symbol X.
 	RedirectToDynImportGotToken = -2

src/cmd/link/internal/ppc64/asm.go

@@ -704,7 +704,7 @@ func xcoffreloc1(arch *sys.Arch, out *ld.OutBuf, ldr *loader.Loader, s loader.Sy
 }
 
 func elfreloc1(ctxt *ld.Link, out *ld.OutBuf, ldr *loader.Loader, s loader.Sym, r loader.ExtReloc, ri int, sectoff int64) bool {
-	// Beware that bit0~bit15 start from the third byte of a instruction in Big-Endian machines.
+	// Beware that bit0~bit15 start from the third byte of an instruction in Big-Endian machines.
 	rt := r.Type
 	if rt == objabi.R_ADDR || rt == objabi.R_POWER_TLS || rt == objabi.R_CALLPOWER {
 	} else {

src/crypto/internal/edwards25519/scalar.go

@@ -104,7 +104,7 @@ func (s *Scalar) Set(x *Scalar) *Scalar {
 // If x is not of the right length, SetUniformBytes returns nil and an error,
 // and the receiver is unchanged.
 //
-// SetUniformBytes can be used to set s to an uniformly distributed value given
+// SetUniformBytes can be used to set s to a uniformly distributed value given
 // 64 uniformly distributed random bytes.
 func (s *Scalar) SetUniformBytes(x []byte) (*Scalar, error) {
 	if len(x) != 64 {

src/crypto/tls/cache.go

@@ -22,7 +22,7 @@ type cacheEntry struct {
 // multiple Conns. Returned references should not be mutated by callers. Certificates
 // are still safe to use after they are removed from the cache.
 //
-// Certificates are returned wrapped in a activeCert struct that should be held by
+// Certificates are returned wrapped in an activeCert struct that should be held by
 // the caller. When references to the activeCert are freed, the number of references
 // to the certificate in the cache is decremented. Once the number of references
 // reaches zero, the entry is evicted from the cache.
@@ -49,7 +49,7 @@ type activeCert struct {
 }
 
 // active increments the number of references to the entry, wraps the
-// certificate in the entry in a activeCert, and sets the finalizer.
+// certificate in the entry in an activeCert, and sets the finalizer.
 //
 // Note that there is a race between active and the finalizer set on the
 // returned activeCert, triggered if active is called after the ref count is

src/crypto/x509/pkcs8.go

@@ -27,8 +27,8 @@ type pkcs8 struct {
 
 // ParsePKCS8PrivateKey parses an unencrypted private key in PKCS #8, ASN.1 DER form.
 //
-// It returns a *rsa.PrivateKey, a *ecdsa.PrivateKey, a ed25519.PrivateKey (not
+// It returns a *rsa.PrivateKey, an *ecdsa.PrivateKey, an ed25519.PrivateKey (not
-// a pointer), or a *ecdh.PrivateKey (for X25519). More types might be supported
+// a pointer), or an *ecdh.PrivateKey (for X25519). More types might be supported
 // in the future.
 //
 // This kind of key is commonly encoded in PEM blocks of type "PRIVATE KEY".

src/debug/pe/file.go

@@ -464,7 +464,7 @@ func (e *FormatError) Error() string {
 	return "unknown error"
 }
 
-// readOptionalHeader accepts a io.ReadSeeker pointing to optional header in the PE file
+// readOptionalHeader accepts an io.ReadSeeker pointing to optional header in the PE file
 // and its size as seen in the file header.
 // It parses the given size of bytes and returns optional header. It infers whether the
 // bytes being parsed refer to 32 bit or 64 bit version of optional header.
@@ -612,7 +612,7 @@ func readOptionalHeader(r io.ReadSeeker, sz uint16) (any, error) {
 	}
 }
 
-// readDataDirectories accepts a io.ReadSeeker pointing to data directories in the PE file,
+// readDataDirectories accepts an io.ReadSeeker pointing to data directories in the PE file,
 // its size and number of data directories as seen in optional header.
 // It parses the given size of bytes and returns given number of data directories.
 func readDataDirectories(r io.ReadSeeker, sz uint16, n uint32) ([]DataDirectory, error) {

src/encoding/gob/encoder.go

@@ -60,7 +60,7 @@ func (enc *Encoder) setError(err error) {
 	}
 }
 
-// writeMessage sends the data item preceded by a unsigned count of its length.
+// writeMessage sends the data item preceded by an unsigned count of its length.
 func (enc *Encoder) writeMessage(w io.Writer, b *encBuffer) {
 	// Space has been reserved for the length at the head of the message.
 	// This is a little dirty: we grab the slice from the bytes.Buffer and massage

src/go/parser/parser.go

@@ -1213,7 +1213,7 @@ parseElements:
 	}
 
 	// TODO(rfindley): the error produced here could be improved, since we could
-	// accept a identifier, 'type', or a '}' at this point.
+	// accept an identifier, 'type', or a '}' at this point.
 	rbrace := p.expect(token.RBRACE)
 
 	return &ast.InterfaceType{

src/index/suffixarray/sais.go

@@ -525,7 +525,7 @@ func induceSubS_8_32(text []byte, sa, freq, bucket []int32) {
 // Second, to avoid text comparison entirely, if an LMS-substring is very short,
 // sa[j/2] records its actual text instead of its length, so that if two such
 // substrings have matching “length,” the text need not be read at all.
-// The definition of “very short” is that the text bytes must pack into an uint32,
+// The definition of “very short” is that the text bytes must pack into a uint32,
 // and the unsigned encoding e must be ≥ len(text), so that it can be
 // distinguished from a valid length.
 func length_8_32(text []byte, sa []int32, numLMS int) {

src/internal/xcoff/ar.go

@@ -216,7 +216,7 @@ func NewArchive(r io.ReaderAt) (*Archive, error) {
 
 // GetFile returns the XCOFF file defined by member name.
 // FIXME: This doesn't work if an archive has two members with the same
-// name which can occur if a archive has both 32-bits and 64-bits files.
+// name which can occur if an archive has both 32-bits and 64-bits files.
 func (arch *Archive) GetFile(name string) (*File, error) {
 	for _, mem := range arch.Members {
 		if mem.Name == name {

src/math/rand/rng.go

@@ -234,7 +234,7 @@ func (rng *rngSource) Int63() int64 {
 	return int64(rng.Uint64() & rngMask)
 }
 
-// Uint64 returns a non-negative pseudo-random 64-bit integer as an uint64.
+// Uint64 returns a non-negative pseudo-random 64-bit integer as a uint64.
 func (rng *rngSource) Uint64() uint64 {
 	rng.tap--
 	if rng.tap < 0 {

src/net/error_posix.go

@@ -12,7 +12,7 @@ import (
 )
 
 // wrapSyscallError takes an error and a syscall name. If the error is
-// a syscall.Errno, it wraps it in a os.SyscallError using the syscall name.
+// a syscall.Errno, it wraps it in an os.SyscallError using the syscall name.
 func wrapSyscallError(name string, err error) error {
 	if _, ok := err.(syscall.Errno); ok {
 		err = os.NewSyscallError(name, err)

src/net/http/cookiejar/jar.go

@@ -365,7 +365,7 @@ func isIP(host string) bool {
 	return net.ParseIP(host) != nil
 }
 
-// defaultPath returns the directory part of an URL's path according to
+// defaultPath returns the directory part of a URL's path according to
 // RFC 6265 section 5.1.4.
 func defaultPath(path string) string {
 	if len(path) == 0 || path[0] != '/' {
@@ -379,7 +379,7 @@ func defaultPath(path string) string {
 	return path[:i] // Path is either of form "/abc/xyz" or "/abc/xyz/".
 }
 
-// newEntry creates an entry from a http.Cookie c. now is the current time and
+// newEntry creates an entry from an http.Cookie c. now is the current time and
 // is compared to c.Expires to determine deletion of c. defPath and host are the
 // default-path and the canonical host name of the URL c was received from.
 //

src/reflect/value.go

@@ -3474,7 +3474,7 @@ func convertOp(dst, src *rtype) func(Value, Type) Value {
 		if dst.Kind() == Pointer && dst.Elem().Kind() == Array && src.Elem() == dst.Elem().Elem() {
 			return cvtSliceArrayPtr
 		}
-		// "x is a slice, T is a array type,
+		// "x is a slice, T is an array type,
 		// and the slice and array types have identical element types."
 		if dst.Kind() == Array && src.Elem() == dst.Elem() {
 			return cvtSliceArray

src/runtime/iface.go

@@ -272,7 +272,7 @@ func panicdottypeI(have *itab, want, iface *_type) {
 	panicdottypeE(t, want, iface)
 }
 
-// panicnildottype is called when doing a i.(T) conversion and the interface i is nil.
+// panicnildottype is called when doing an i.(T) conversion and the interface i is nil.
 // want = the static type we're trying to convert to.
 func panicnildottype(want *_type) {
 	panic(&TypeAssertionError{nil, nil, want, ""})

src/syscall/js/js.go

@@ -570,7 +570,7 @@ func (e *ValueError) Error() string {
 }
 
 // CopyBytesToGo copies bytes from src to dst.
-// It panics if src is not an Uint8Array or Uint8ClampedArray.
+// It panics if src is not a Uint8Array or Uint8ClampedArray.
 // It returns the number of bytes copied, which will be the minimum of the lengths of src and dst.
 func CopyBytesToGo(dst []byte, src Value) int {
 	n, ok := copyBytesToGo(dst, src.ref)
@@ -585,7 +585,7 @@ func CopyBytesToGo(dst []byte, src Value) int {
 func copyBytesToGo(dst []byte, src ref) (int, bool)
 
 // CopyBytesToJS copies bytes from src to dst.
-// It panics if dst is not an Uint8Array or Uint8ClampedArray.
+// It panics if dst is not a Uint8Array or Uint8ClampedArray.
 // It returns the number of bytes copied, which will be the minimum of the lengths of src and dst.
 func CopyBytesToJS(dst Value, src []byte) int {
 	n, ok := copyBytesToJS(dst.ref, src)