go-gno-compatibility.md

Go - Gno compatibility

Gno is modeled after Go 1.17.

Reserved keywords

keyword	support
break	full
case	full
const	full
continue	full
default	full
defer	full
else	full
fallthrough	full
for	full
func	full
go	missing (after launch)
goto	full
if	full
import	full
interface	full
package	full
range	full
return	full
select	missing (after launch)
struct	full
switch	full
type	full
var	full

Generics are currently not implemented.

Note that Gno does not support shadowing of built-in types. While the following built-in typecasting assignment would work in Go, this is not supported in Gno.

rune := rune('a')

Builtin types

type	usage	persistency
bool	full	full
byte	full	full
int, int8, int16, int32, int64	full	full
uint, uint8, uint16, uint32, uint64	full	full
float32, float64	full	full
complex64, complex128	missing (TBD)	missing
uintptr, unsafe.Pointer	missing	missing
string	full	full
rune	full	full
interface{} / any	full	full
[]T (slices)	full	full*
[N]T (arrays)	full	full*
map[T1]T2	full	full*
func (T1...) T2...	full	full (needs more tests)
*T (pointers)	full	full*
chan T (channels)	missing (after launch)	missing (after launch)

*: depends on T/T1/T2

Additional builtin types:

type	comment
bigint	Based on math/big.Int
bigdec	Based on https://github.com/cockroachdb/apd, (see #306)

Stdlibs

Legend:

• nondet: the standard library in question would require non-deterministic behaviour to implement as in Go, such as cryptographical randomness or os/network access. The library may still be implemented at one point, with a different API.
• gospec: the standard library is very Go-specific -- for instance, it is used for debugging information or for parsing/build Go source code. A Gno version may exist at one point, likely with a different package name or semantics.
• gnics: the standard library requires generics.
• test: the standard library is currently available for use exclusively in test contexts, and may have limited functionality.
• cmd: the Go standard library is a command -- a direct equivalent in Gno would not be useful.
• tbd: whether to include the standard library or not is still up for discussion.
• todo: the standard library is to be added, and contributions are welcome.
• part: the standard library is partially implemented in Gno, and contributions are welcome to add the missing functionality.
• full: the standard library is fully implemented in Gno.

package	status
archive/tar	tbd
archive/zip	tbd
arena	improb
bufio	full
builtin	full1
bytes	full
cmd/*	cmd
compress/bzip2	tbd
compress/flate	tbd
compress/gzip	tbd
compress/lzw	tbd
compress/zlib	tbd
container/heap	tbd
container/list	tbd
container/ring	tbd
context	tbd
crypto	todo
crypto/aes	todo
crypto/boring	tbd
crypto/cipher	part
crypto/des	tbd
crypto/dsa	tbd
crypto/ecdh	tbd
crypto/ecdsa	tbd
crypto/ed25519	part2
crypto/elliptic	tbd
crypto/hmac	todo
crypto/md5	test3
crypto/rand	nondet
crypto/rc4	tbd
crypto/rsa	tbd
crypto/sha1	test3
crypto/sha256	part4
crypto/sha512	tbd
crypto/subtle	tbd
crypto/tls	nondet
crypto/tls/fipsonly	nondet
crypto/x509	tbd
crypto/x509/pkix	tbd
database/sql	nondet
database/sql/driver	nondet
debug/buildinfo	gospec
debug/dwarf	gospec
debug/elf	gospec
debug/gosym	gospec
debug/macho	gospec
debug/pe	gospec
debug/plan9obj	gospec
embed	tbd
encoding	full
encoding/ascii85	todo
encoding/asn1	todo
encoding/base32	todo
encoding/base64	full
encoding/binary	part
encoding/csv	todo
encoding/gob	tbd
encoding/hex	full
encoding/json	todo
encoding/pem	todo
encoding/xml	todo
errors	part
expvar	tbd
flag	nondet
fmt	test5
go/ast	gospec
go/build	gospec
go/build/constraint	gospec
go/constant	gospec
go/doc	gospec
go/doc/comment	gospec
go/format	gospec
go/importer	gospec
go/parser	gospec
go/printer	gospec
go/scanner	gospec
go/token	gospec
go/types	gospec
hash	full
hash/adler32	full
hash/crc32	todo
hash/crc64	todo
hash/fnv	todo
hash/maphash	todo
html	full
html/template	todo
image	tbd
image/color	tbd
image/color/palette	tbd
image/draw	tbd
image/gif	tbd
image/jpeg	tbd
image/png	tbd
index/suffixarray	tbd
io	full
io/fs	tbd
io/ioutil	removed6
log	tbd
log/slog	tbd
log/syslog	nondet
maps	gnics
math	full
math/big	tbd
math/bits	full
math/cmplx	tbd
math/rand	full7
mime	tbd
mime/multipart	tbd
mime/quotedprintable	tbd
net	nondet
net/http	nondet
net/http/cgi	nondet
net/http/cookiejar	nondet
net/http/fcgi	nondet
net/http/httptest	nondet
net/http/httptrace	nondet
net/http/httputil	nondet
net/http/internal	nondet
net/http/pprof	nondet
net/mail	nondet
net/netip	nondet
net/rpc	nondet
net/rpc/jsonrpc	nondet
net/smtp	nondet
net/textproto	nondet
net/url	full
os	nondet
os/exec	nondet
os/signal	nondet
os/user	nondet
path	full
path/filepath	nondet
plugin	nondet
reflect	todo
regexp	full
regexp/syntax	full
runtime	gospec
runtime/asan	gospec
runtime/cgo	gospec
runtime/coverage	gospec
runtime/debug	gospec
runtime/metrics	gospec
runtime/msan	gospec
runtime/pprof	gospec
runtime/race	gospec
runtime/trace	gospec
slices	gnics
sort	part8
strconv	full9
strings	full
sync	tbd
sync/atomic	tbd
syscall	nondet
syscall/js	nondet
testing	part
testing/fstest	tbd
testing/iotest	tbd
testing/quick	tbd
text/scanner	todo
text/tabwriter	todo
text/template	todo
text/template/parse	todo
time	full10
time/tzdata	tbd
unicode	full
unicode/utf16	full
unicode/utf8	full
unsafe	nondet

Tooling (gno binary)

go command	gno command	comment
go bug	gno bug	same behavior
go build	gno tool transpile -gobuild	same intention, limited compatibility
go clean	gno clean	same intention, limited compatibility
go doc	gno doc	limited compatibility; see #522
go env	gno env
go fix
go fmt	gno fmt	gofmt (& similar tools, like gofumpt) works on gno code.
go generate
go get		see gno mod download.
go help	gno $cmd --help	ie. gno doc --help
go install
go list
go mod	gno mod
+ go mod init	gno mod init	same behavior
+ go mod download	gno mod download	same behavior
+ go mod tidy	gno mod tidy	same behavior
+ go mod why	gno mod why	same intention
	gno tool transpile
go work
	gno tool repl
go run	gno run
go test	gno test	limited compatibility
go tool
go version
go vet
golint	gno tool lint	same intention

Footnotes

1. builtin is a "fake" package that exists to document the behaviour of some builtin functions. The "fake" package does not currently exist in Gno, but all functions up to Go 1.17 exist, except for those relating to complex (real or imag) or channel types. ↩

2. crypto/ed25519 is currently only implemented for Verify, which should still cover a majority of use cases. A full implementation is welcome. ↩

3. crypto/sha1 and crypto/md5 implement "deprecated" hashing algorithms, widely considered unsafe for cryptographic hashing. Decision on whether to include these as part of the official standard libraries is still pending. ↩ ↩²

4. crypto/sha256 is currently only implemented for Sum256, which should still cover a majority of use cases. A full implementation is welcome. ↩

5. like many other encoding packages, fmt depends on reflect to be added. For now, package gno.land/p/demo/ufmt may do what you need. In test functions, fmt works. ↩

6. io/ioutil is deprecated in Go. Its functionality has been moved to packages os and io. The functions which have been moved in io are implemented in that package. ↩

7. math/rand in Gno ports over Go's math/rand/v2. ↩

8. sort has the notable omission of sort.Slice. You'll need to write a bit of boilerplate, but you can use sort.Interface + sort.Sort! ↩

9. strconv does not have the methods relating to types complex64 and complex128. ↩

10. time.Now returns the block time rather than the system time, for determinism. Concurrent functionality (such as time.Ticker) is not implemented. ↩