elvish/pkg/eval/compile_value.go

586 lines
13 KiB
Go

package eval
import (
"errors"
"fmt"
"strings"
"src.elv.sh/pkg/diag"
"src.elv.sh/pkg/eval/errs"
"src.elv.sh/pkg/eval/vals"
"src.elv.sh/pkg/eval/vars"
"src.elv.sh/pkg/fsutil"
"src.elv.sh/pkg/glob"
"src.elv.sh/pkg/parse"
)
// An operation that produces values.
type valuesOp interface {
diag.Ranger
exec(*Frame) ([]any, Exception)
}
var outputCaptureBufferSize = 16
// Can be mutated for testing.
var getHome = fsutil.GetHome
func (cp *compiler) compoundOp(n *parse.Compound) valuesOp {
if len(n.Indexings) == 0 {
return literalValues(n, "")
}
tilde := false
indexings := n.Indexings
if n.Indexings[0].Head.Type == parse.Tilde {
// A lone ~.
if len(n.Indexings) == 1 {
return loneTildeOp{n.Range()}
}
tilde = true
indexings = indexings[1:]
}
return compoundOp{n.Range(), tilde, cp.indexingOps(indexings)}
}
type loneTildeOp struct{ diag.Ranging }
func (op loneTildeOp) exec(fm *Frame) ([]any, Exception) {
home, err := getHome("")
if err != nil {
return nil, fm.errorp(op, err)
}
return []any{home}, nil
}
func (cp *compiler) compoundOps(ns []*parse.Compound) []valuesOp {
ops := make([]valuesOp, len(ns))
for i, n := range ns {
ops[i] = cp.compoundOp(n)
}
return ops
}
type compoundOp struct {
diag.Ranging
tilde bool
subops []valuesOp
}
func (op compoundOp) exec(fm *Frame) ([]any, Exception) {
// Accumulator.
vs, exc := op.subops[0].exec(fm)
if exc != nil {
return nil, exc
}
for _, subop := range op.subops[1:] {
us, exc := subop.exec(fm)
if exc != nil {
return nil, exc
}
var err error
vs, err = outerProduct(vs, us, vals.Concat)
if err != nil {
return nil, fm.errorp(op, err)
}
}
if op.tilde {
newvs := make([]any, len(vs))
for i, v := range vs {
tilded, err := doTilde(v)
if err != nil {
return nil, fm.errorp(op, err)
}
newvs[i] = tilded
}
vs = newvs
}
hasGlob := false
for _, v := range vs {
if _, ok := v.(globPattern); ok {
hasGlob = true
break
}
}
if hasGlob {
newvs := make([]any, 0, len(vs))
for _, v := range vs {
if gp, ok := v.(globPattern); ok {
results, err := doGlob(fm.Context(), gp)
if err != nil {
return nil, fm.errorp(op, err)
}
newvs = append(newvs, results...)
} else {
newvs = append(newvs, v)
}
}
vs = newvs
}
return vs, nil
}
func outerProduct(vs []any, us []any, f func(any, any) (any, error)) ([]any, error) {
ws := make([]any, len(vs)*len(us))
nu := len(us)
for i, v := range vs {
for j, u := range us {
var err error
ws[i*nu+j], err = f(v, u)
if err != nil {
return nil, err
}
}
}
return ws, nil
}
// Errors thrown when globbing.
var (
ErrBadglobPattern = errors.New("bad globPattern; elvish bug")
ErrCannotDetermineUsername = errors.New("cannot determine user name from glob pattern")
)
func doTilde(v any) (any, error) {
switch v := v.(type) {
case string:
s := v
// TODO: Make this correct on Windows.
i := strings.Index(s, "/")
var uname, rest string
if i == -1 {
uname = s
} else {
uname = s[:i]
rest = s[i:]
}
dir, err := getHome(uname)
if err != nil {
return nil, err
}
return dir + rest, nil
case globPattern:
if len(v.Segments) == 0 {
return nil, ErrBadglobPattern
}
switch seg := v.Segments[0].(type) {
case glob.Literal:
if len(v.Segments) == 1 {
return nil, ErrBadglobPattern
}
_, isSlash := v.Segments[1].(glob.Slash)
if isSlash {
// ~username/xxx. Replace the first segment with the home
// directory of the specified user.
dir, err := getHome(seg.Data)
if err != nil {
return nil, err
}
v.Segments[0] = glob.Literal{Data: dir}
return v, nil
}
case glob.Slash:
dir, err := getHome("")
if err != nil {
return nil, err
}
v.DirOverride = dir
return v, nil
}
return nil, ErrCannotDetermineUsername
default:
return nil, fmt.Errorf("tilde doesn't work on value of type %s", vals.Kind(v))
}
}
func (cp *compiler) arrayOp(n *parse.Array) valuesOp {
return seqValuesOp{n.Range(), cp.compoundOps(n.Compounds)}
}
func (cp *compiler) arrayOps(ns []*parse.Array) []valuesOp {
ops := make([]valuesOp, len(ns))
for i, n := range ns {
ops[i] = cp.arrayOp(n)
}
return ops
}
func (cp *compiler) indexingOp(n *parse.Indexing) valuesOp {
if len(n.Indices) == 0 {
return cp.primaryOp(n.Head)
}
return &indexingOp{n.Range(), cp.primaryOp(n.Head), cp.arrayOps(n.Indices)}
}
func (cp *compiler) indexingOps(ns []*parse.Indexing) []valuesOp {
ops := make([]valuesOp, len(ns))
for i, n := range ns {
ops[i] = cp.indexingOp(n)
}
return ops
}
type indexingOp struct {
diag.Ranging
headOp valuesOp
indexOps []valuesOp
}
func (op *indexingOp) exec(fm *Frame) ([]any, Exception) {
vs, exc := op.headOp.exec(fm)
if exc != nil {
return nil, exc
}
for _, indexOp := range op.indexOps {
indices, exc := indexOp.exec(fm)
if exc != nil {
return nil, exc
}
newvs := make([]any, 0, len(vs)*len(indices))
for _, v := range vs {
for _, index := range indices {
result, err := vals.Index(v, index)
if err != nil {
return nil, fm.errorp(op, err)
}
newvs = append(newvs, result)
}
}
vs = newvs
}
return vs, nil
}
func (cp *compiler) primaryOp(n *parse.Primary) valuesOp {
switch n.Type {
case parse.Bareword, parse.SingleQuoted, parse.DoubleQuoted:
return literalValues(n, n.Value)
case parse.Variable:
sigil, qname := SplitSigil(n.Value)
ref := resolveVarRef(cp, qname, n)
if ref == nil {
cp.autofixUnresolvedVar(qname)
cp.errorpf(n, "variable $%s not found", parse.Quote(qname))
}
return &variableOp{n.Range(), sigil != "", qname, ref}
case parse.Wildcard:
seg, err := wildcardToSegment(parse.SourceText(n))
if err != nil {
cp.errorpf(n, "%s", err)
}
vs := []any{
globPattern{Pattern: glob.Pattern{Segments: []glob.Segment{seg}, DirOverride: ""},
Flags: 0, Buts: nil, TypeCb: nil}}
return literalValues(n, vs...)
case parse.Tilde:
cp.errorpf(n, "compiler bug: Tilde not handled in .compound")
return literalValues(n, "~")
case parse.ExceptionCapture:
return exceptionCaptureOp{n.Range(), cp.chunkOp(n.Chunk)}
case parse.OutputCapture:
return outputCaptureOp{n.Range(), cp.chunkOp(n.Chunk)}
case parse.List:
return listOp{n.Range(), cp.compoundOps(n.Elements)}
case parse.Lambda:
return cp.lambda(n)
case parse.Map:
return mapOp{n.Range(), cp.mapPairs(n.MapPairs)}
case parse.Braced:
return seqValuesOp{n.Range(), cp.compoundOps(n.Braced)}
default:
cp.errorpf(n, "bad PrimaryType; parser bug")
return literalValues(n, parse.SourceText(n))
}
}
func (cp *compiler) primaryOps(ns []*parse.Primary) []valuesOp {
ops := make([]valuesOp, len(ns))
for i, n := range ns {
ops[i] = cp.primaryOp(n)
}
return ops
}
type variableOp struct {
diag.Ranging
explode bool
qname string
ref *varRef
}
func (op variableOp) exec(fm *Frame) ([]any, Exception) {
variable := deref(fm, op.ref)
if variable == nil {
return nil, fm.errorpf(op, "variable $%s not found", parse.Quote(op.qname))
}
value := variable.Get()
if op.explode {
vs, err := vals.Collect(value)
return vs, fm.errorp(op, err)
}
return []any{value}, nil
}
type listOp struct {
diag.Ranging
subops []valuesOp
}
func (op listOp) exec(fm *Frame) ([]any, Exception) {
list := vals.EmptyList
for _, subop := range op.subops {
moreValues, exc := subop.exec(fm)
if exc != nil {
return nil, exc
}
for _, moreValue := range moreValues {
list = list.Conj(moreValue)
}
}
return []any{list}, nil
}
type exceptionCaptureOp struct {
diag.Ranging
subop effectOp
}
func (op exceptionCaptureOp) exec(fm *Frame) ([]any, Exception) {
exc := op.subop.exec(fm)
if exc == nil {
return []any{OK}, nil
}
return []any{exc}, nil
}
type outputCaptureOp struct {
diag.Ranging
subop effectOp
}
func (op outputCaptureOp) exec(fm *Frame) ([]any, Exception) {
outPort, collect, err := ValueCapturePort()
if err != nil {
return nil, fm.errorp(op, err)
}
exc := op.subop.exec(fm.forkWithOutput("[output capture]", outPort))
return collect(), exc
}
func (cp *compiler) lambda(n *parse.Primary) valuesOp {
// Parse signature.
var (
argNames []string
restArg int = -1
optNames []string
optDefaultOps []valuesOp
)
if len(n.Elements) > 0 {
// Argument list.
argNames = make([]string, len(n.Elements))
for i, arg := range n.Elements {
ref := stringLiteralOrError(cp, arg, "argument name")
sigil, qname := SplitSigil(ref)
name, rest := SplitQName(qname)
if rest != "" {
cp.errorpf(arg, "argument name must be unqualified")
}
if name == "" {
cp.errorpf(arg, "argument name must not be empty")
}
if sigil == "@" {
if restArg != -1 {
cp.errorpf(arg, "only one argument may have @ prefix")
}
restArg = i
}
argNames[i] = name
}
}
if len(n.MapPairs) > 0 {
optNames = make([]string, len(n.MapPairs))
optDefaultOps = make([]valuesOp, len(n.MapPairs))
for i, opt := range n.MapPairs {
qname := stringLiteralOrError(cp, opt.Key, "option name")
name, rest := SplitQName(qname)
if rest != "" {
cp.errorpf(opt.Key, "option name must be unqualified")
}
if name == "" {
cp.errorpf(opt.Key, "option name must not be empty")
}
optNames[i] = name
if opt.Value == nil {
cp.errorpf(opt.Key, "option must have default value")
} else {
optDefaultOps[i] = cp.compoundOp(opt.Value)
}
}
}
local, capture := cp.pushScope()
for _, argName := range argNames {
local.add(argName)
}
for _, optName := range optNames {
local.add(optName)
}
scopeSizeInit := len(local.infos)
chunkOp := cp.chunkOp(n.Chunk)
newLocal := local.infos[scopeSizeInit:]
cp.popScope()
return &lambdaOp{n.Range(), argNames, restArg, optNames, optDefaultOps, newLocal, capture, chunkOp, cp.srcMeta}
}
type lambdaOp struct {
diag.Ranging
argNames []string
restArg int
optNames []string
optDefaultOps []valuesOp
newLocal []staticVarInfo
capture *staticUpNs
subop effectOp
srcMeta parse.Source
}
func (op *lambdaOp) exec(fm *Frame) ([]any, Exception) {
capture := &Ns{
make([]vars.Var, len(op.capture.infos)),
make([]staticVarInfo, len(op.capture.infos))}
for i, info := range op.capture.infos {
if info.local {
capture.slots[i] = fm.local.slots[info.index]
capture.infos[i] = fm.local.infos[info.index]
} else {
capture.slots[i] = fm.up.slots[info.index]
capture.infos[i] = fm.up.infos[info.index]
}
}
optDefaults := make([]any, len(op.optDefaultOps))
for i, op := range op.optDefaultOps {
defaultValue, err := evalForValue(fm, op, "option default value")
if err != nil {
return nil, err
}
optDefaults[i] = defaultValue
}
return []any{&Closure{op.argNames, op.restArg, op.optNames, optDefaults, op.srcMeta, op.Range(), op.subop, op.newLocal, capture}}, nil
}
type mapOp struct {
diag.Ranging
pairsOp *mapPairsOp
}
func (op mapOp) exec(fm *Frame) ([]any, Exception) {
m := vals.EmptyMap
exc := op.pairsOp.exec(fm, func(k, v any) Exception {
m = m.Assoc(k, v)
return nil
})
if exc != nil {
return nil, exc
}
return []any{m}, nil
}
func (cp *compiler) mapPairs(pairs []*parse.MapPair) *mapPairsOp {
npairs := len(pairs)
keysOps := make([]valuesOp, npairs)
valuesOps := make([]valuesOp, npairs)
begins, ends := make([]int, npairs), make([]int, npairs)
for i, pair := range pairs {
keysOps[i] = cp.compoundOp(pair.Key)
if pair.Value == nil {
p := pair.Range().To
valuesOps[i] = literalValues(diag.PointRanging(p), true)
} else {
valuesOps[i] = cp.compoundOp(pairs[i].Value)
}
begins[i], ends[i] = pair.Range().From, pair.Range().To
}
return &mapPairsOp{keysOps, valuesOps, begins, ends}
}
type mapPairsOp struct {
keysOps []valuesOp
valuesOps []valuesOp
begins []int
ends []int
}
func (op *mapPairsOp) exec(fm *Frame, f func(k, v any) Exception) Exception {
for i := range op.keysOps {
keys, exc := op.keysOps[i].exec(fm)
if exc != nil {
return exc
}
values, exc := op.valuesOps[i].exec(fm)
if exc != nil {
return exc
}
if len(keys) != len(values) {
return fm.errorpf(diag.Ranging{From: op.begins[i], To: op.ends[i]},
"%d keys but %d values", len(keys), len(values))
}
for j, key := range keys {
err := f(key, values[j])
if err != nil {
return err
}
}
}
return nil
}
type literalValuesOp struct {
diag.Ranging
values []any
}
func (op literalValuesOp) exec(*Frame) ([]any, Exception) {
return op.values, nil
}
func literalValues(r diag.Ranger, vs ...any) valuesOp {
return literalValuesOp{r.Range(), vs}
}
type seqValuesOp struct {
diag.Ranging
subops []valuesOp
}
func (op seqValuesOp) exec(fm *Frame) ([]any, Exception) {
var values []any
for _, subop := range op.subops {
moreValues, exc := subop.exec(fm)
if exc != nil {
return nil, exc
}
values = append(values, moreValues...)
}
return values, nil
}
type nopValuesOp struct{ diag.Ranging }
func (nopValuesOp) exec(fm *Frame) ([]any, Exception) { return nil, nil }
func evalForValue(fm *Frame, op valuesOp, what string) (any, Exception) {
values, exc := op.exec(fm)
if exc != nil {
return nil, exc
}
if len(values) != 1 {
return nil, fm.errorp(op, errs.ArityMismatch{What: what,
ValidLow: 1, ValidHigh: 1, Actual: len(values)})
}
return values[0], nil
}