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// Copyright 2018 The CUE Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package cue
import (
"bytes"
"math/big"
"regexp"
"sort"
"strings"
"time"
"cuelang.org/go/cue/token"
"github.com/cockroachdb/apd"
)
// binSrc returns a baseValue representing a binary expression of the given
// values.
func binSrc(pos token.Pos, op op, a, b value) baseValue {
return baseValue{&computedSource{pos, op, a, b}}
}
func unify(ctx *context, src source, left, right evaluated) evaluated {
return binOp(ctx, src, opUnify, left, right)
}
func binOp(ctx *context, src source, op op, left, right evaluated) (result evaluated) {
if b, ok := left.(*bottom); ok {
if op == opUnify && b.exprDepth == 0 && cycleError(b) != nil {
ctx.cycleErr = true
return right
}
return left
}
if b, ok := right.(*bottom); ok {
if op == opUnify && b.exprDepth == 0 && cycleError(b) != nil {
ctx.cycleErr = true
return left
}
return right
}
leftKind := left.kind()
rightKind := right.kind()
kind, invert := matchBinOpKind(op, leftKind, rightKind)
if kind == bottomKind {
return ctx.mkIncompatible(src, op, left, right)
}
if kind.hasReferences() {
panic("unexpected references in expression")
}
if invert {
left, right = right, left
}
if op != opUnify {
// Any operation other than unification or disjunction must be on
// concrete types. Disjunction is handled separately.
if !leftKind.isGround() || !rightKind.isGround() {
return ctx.mkErr(src, codeIncomplete, "incomplete error")
}
ctx.incEvalDepth()
v := left.binOp(ctx, src, op, right) // may return incomplete
ctx.decEvalDepth()
return v
}
// op == opUnify
// TODO: unify type masks.
if left == right {
return left
}
if isTop(left) {
return right
}
if isTop(right) {
return left
}
if dl, ok := left.(*disjunction); ok {
return distribute(ctx, src, dl, right)
} else if dr, ok := right.(*disjunction); ok {
return distribute(ctx, src, dr, left)
}
if _, ok := right.(*unification); ok {
return right.binOp(ctx, src, opUnify, left)
}
// TODO: value may be incomplete if there is a cycle. Instead of an error
// schedule an assert and return the atomic value, if applicable.
v := left.binOp(ctx, src, op, right)
if isBottom(v) {
v := right.binOp(ctx, src, op, left)
// Return the original failure if both fail, as this will result in
// better error messages.
if !isBottom(v) {
return v
}
}
return v
}
type mVal struct {
val evaluated
mark bool
}
// distribute distributes a value over the element of a disjunction in a
// unification operation.
// TODO: this is an exponential algorithm. There is no reason to have to
// resolve this early. Revise this to only do early pruning but not a full
// evaluation.
func distribute(ctx *context, src source, x, y evaluated) evaluated {
dn := &disjunction{baseValue: src.base()}
dist(ctx, dn, false, mVal{x, true}, mVal{y, true})
return dn.normalize(ctx, src).val
}
func dist(ctx *context, d *disjunction, mark bool, x, y mVal) {
if dx, ok := x.val.(*disjunction); ok {
if dx.hasDefaults {
mark = true
d.hasDefaults = true
}
for _, dxv := range dx.values {
m := dxv.marked || !dx.hasDefaults
dist(ctx, d, mark, mVal{dxv.val.evalPartial(ctx), m}, y)
}
return
}
if dy, ok := y.val.(*disjunction); ok {
if dy.hasDefaults {
mark = true
d.hasDefaults = true
}
for _, dxy := range dy.values {
m := dxy.marked || !dy.hasDefaults
dist(ctx, d, mark, x, mVal{dxy.val.evalPartial(ctx), m})
}
return
}
src := binSrc(token.NoPos, opUnify, x.val, y.val)
d.add(ctx, binOp(ctx, src, opUnify, x.val, y.val), mark && x.mark && y.mark)
}
func (x *disjunction) binOp(ctx *context, src source, op op, other evaluated) evaluated {
panic("unreachable: special-cased")
}
func (x *bottom) binOp(ctx *context, src source, op op, other evaluated) evaluated {
panic("unreachable: special-cased")
}
func (x *unification) add(ctx *context, src source, v evaluated) evaluated {
for progress := true; progress; {
progress = false
k := 0
for i, vx := range x.values {
a := binOp(ctx, src, opUnify, vx, v)
switch _, isUnify := a.(*unification); {
case isBottom(a):
if !isIncomplete(a) {
return a
}
fallthrough
case isUnify:
x.values[k] = x.values[i]
k++
continue
}
// k will not be raised in this iteration. So the outer loop
// will ultimately terminate as k reaches 0.
// In practice it is seems unlikely that there will be more than
// two iterations for any addition.
// progress = true
v = a
}
if k == 0 {
return v
}
x.values = x.values[:k]
}
x.values = append(x.values, v)
return nil
}
func (x *unification) binOp(ctx *context, src source, op op, other evaluated) evaluated {
if op == opUnify {
u := &unification{baseValue: baseValue{src}}
u.values = append(u.values, x.values...)
if y, ok := other.(*unification); ok {
for _, vy := range y.values {
if v := u.add(ctx, src, vy); v != nil {
return v
}
}
} else if v := u.add(ctx, src, other); v != nil {
return v
}
return u
}
return ctx.mkIncompatible(src, op, x, other)
}
func (x *top) binOp(ctx *context, src source, op op, other evaluated) evaluated {
switch op {
case opUnify:
return other
}
src = mkBin(ctx, src.Pos(), op, x, other)
return ctx.mkErr(src, codeIncomplete, "binary operation on (incomplete) top value")
}
func (x *basicType) binOp(ctx *context, src source, op op, other evaluated) evaluated {
k := unifyType(x.kind(), other.kind())
switch y := other.(type) {
case *basicType:
switch op {
// TODO: other types.
case opUnify:
if k&typeKinds != bottomKind {
return &basicType{binSrc(src.Pos(), op, x, other), k & typeKinds}
}
}
case *bound:
src = mkBin(ctx, src.Pos(), op, x, other)
return ctx.mkErr(src, codeIncomplete, "%s with incomplete values", op)
case *numLit:
if op == opUnify {
if k == y.k {
return y
}
i := *y
i.k = k
return &i
}
src = mkBin(ctx, src.Pos(), op, x, other)
return ctx.mkErr(src, codeIncomplete, "%s with incomplete values", op)
default:
if k&typeKinds != bottomKind {
return other
}
}
return ctx.mkIncompatible(src, op, x, other)
}
func checkBounds(ctx *context, src source, r *bound, op op, a, b evaluated) evaluated {
v := binOp(ctx, src, op, a, b)
if isBottom(v) || !v.(*boolLit).b {
return errOutOfBounds(ctx, src.Pos(), r, a)
}
return nil
}
func errOutOfBounds(ctx *context, pos token.Pos, r *bound, v evaluated) *bottom {
if pos == token.NoPos {
pos = r.Pos()
}
e := mkBin(ctx, pos, opUnify, r, v)
msg := "%v not within bound %v"
switch r.op {
case opNeq, opNMat:
msg = "%v excluded by %v"
case opMat:
msg = "%v does not match %v"
}
return ctx.mkErr(e, msg, debugStr(ctx, v), debugStr(ctx, r))
}
func opInfo(op op) (cmp op, norm int) {
switch op {
case opGtr:
return opGeq, 1
case opGeq:
return opGtr, 1
case opLss:
return opLeq, -1
case opLeq:
return opLss, -1
case opNeq:
return opNeq, 0
case opMat:
return opMat, 2
case opNMat:
return opNMat, 3
}
panic("cue: unreachable")
}
func (x *bound) binOp(ctx *context, src source, op op, other evaluated) evaluated {
xv := x.value.(evaluated)
newSrc := binSrc(src.Pos(), op, x, other)
switch op {
case opUnify:
k, _ := matchBinOpKind(opUnify, x.kind(), other.kind())
if k == bottomKind {
break
}
switch y := other.(type) {
case *basicType:
k := unifyType(x.k, y.kind())
if k == x.k {
return x
}
return newBound(ctx, newSrc.base(), x.op, k, xv)
case *bound:
yv := y.value.(evaluated)
if !xv.kind().isGround() || !yv.kind().isGround() {
return ctx.mkErr(newSrc, codeIncomplete, "cannot add incomplete values")
}
cmp, xCat := opInfo(x.op)
_, yCat := opInfo(y.op)
switch {
case xCat == yCat:
if x.op == opNeq || x.op == opMat || x.op == opNMat {
if test(ctx, x, opEql, xv, yv) {
return x
}
break // unify the two bounds
}
// xCat == yCat && x.op != opNeq
// > a & >= b
// > a if a >= b
// >= b if a < b
// > a & > b
// > a if a >= b
// > b if a < b
// >= a & > b
// >= a if a > b
// > b if a <= b
// >= a & >= b
// >= a if a > b
// >= b if a <= b
// inverse is true as well.
// Tighten bound.
if test(ctx, x, cmp, xv, yv) {
return x
}
return y
case xCat == -yCat:
if xCat == -1 {
x, y = y, x
}
a, aOK := x.value.(evaluated).(*numLit)
b, bOK := y.value.(evaluated).(*numLit)
if !aOK || !bOK {
break
}
var d apd.Decimal
cond, err := apd.BaseContext.Sub(&d, &b.v, &a.v)
if cond.Inexact() || err != nil {
break
}
// attempt simplification
// numbers
// >=a & <=b
// a if a == b
// _|_ if a < b
// >=a & <b
// _|_ if b <= a
// >a & <=b
// _|_ if b <= a
// >a & <b
// _|_ if b <= a
// integers
// >=a & <=b
// a if b-a == 0
// _|_ if a < b
// >=a & <b
// a if b-a == 1
// _|_ if b <= a
// >a & <=b
// b if b-a == 1
// _|_ if b <= a
// >a & <b
// a+1 if b-a == 2
// _|_ if b <= a
switch diff, err := d.Int64(); {
case err != nil:
case diff == 1:
if k&floatKind == 0 {
if x.op == opGeq && y.op == opLss {
return a
}
if x.op == opGtr && y.op == opLeq {
return b
}
}
case diff == 2:
if k&floatKind == 0 && x.op == opGtr && y.op == opLss {
apd.BaseContext.Add(&d, d.SetInt64(1), &a.v)
n := *a
n.k = k
n.v = d
return &n
}
case diff == 0:
if x.op == opGeq && y.op == opLeq {
return a
}
fallthrough
case d.Negative:
return ctx.mkErr(newSrc, "incompatible bounds %v and %v",
debugStr(ctx, x), debugStr(ctx, y))
}
case x.op == opNeq:
if !test(ctx, x, y.op, xv, yv) {
return y
}
case y.op == opNeq:
if !test(ctx, x, x.op, yv, xv) {
return x
}
}
return &unification{newSrc, []evaluated{x, y}}
case *numLit:
if err := checkBounds(ctx, src, x, x.op, y, xv); err != nil {
return err
}
// Narrow down number type.
if y.k != k {
n := *y
n.k = k
return &n
}
return other
case *nullLit, *boolLit, *durationLit, *list, *structLit, *stringLit, *bytesLit:
// All remaining concrete types. This includes non-comparable types
// for comparison to null.
if err := checkBounds(ctx, src, x, x.op, y, xv); err != nil {
return err
}
return y
}
}
return ctx.mkIncompatible(src, op, x, other)
}
func (x *customValidator) binOp(ctx *context, src source, op op, other evaluated) evaluated {
newSrc := binSrc(src.Pos(), op, x, other)
switch op {
case opUnify:
k, _ := matchBinOpKind(opUnify, x.kind(), other.kind())
if k == bottomKind {
break
}
switch y := other.(type) {
case *basicType:
k := unifyType(x.kind(), y.kind())
if k == x.kind() {
return x
}
return &unification{newSrc, []evaluated{x, y}}
case *bound:
return &unification{newSrc, []evaluated{x, y}}
case *numLit:
if err := x.check(ctx, y); err != nil {
return err
}
// Narrow down number type.
if y.k != k {
n := *y
n.k = k
return &n
}
return other
case *nullLit, *boolLit, *durationLit, *list, *structLit, *stringLit, *bytesLit:
// All remaining concrete types. This includes non-comparable types
// for comparison to null.
if err := x.check(ctx, y); err != nil {
return err
}
return y
}
}
return ctx.mkIncompatible(src, op, x, other)
}
func (x *customValidator) check(ctx *context, v evaluated) evaluated {
args := make([]evaluated, 1+len(x.args))
args[0] = v
for i, v := range x.args {
args[1+i] = v.(evaluated)
}
res := x.call.call(ctx, x, args...)
if isBottom(res) {
return res.(evaluated)
}
if b, ok := res.(*boolLit); !ok {
// should never reach here
return ctx.mkErr(x, "invalid custom validator")
} else if !b.b {
var buf bytes.Buffer
buf.WriteString(x.call.Name)
buf.WriteString("(")
for _, a := range x.args {
buf.WriteString(debugStr(ctx, a))
}
buf.WriteString(")")
return ctx.mkErr(x, "value %v not in %v", debugStr(ctx, v), buf.String())
}
return nil
}
func evalLambda(ctx *context, a value) (l *lambdaExpr, err evaluated) {
if a == nil {
return nil, nil
}
// NOTE: the values of a lambda might still be a disjunction
e := ctx.manifest(a)
if isBottom(e) {
return nil, e
}
l, ok := e.(*lambdaExpr)
if !ok {
return nil, ctx.mkErr(a, "value must be lambda")
}
return ctx.deref(l).(*lambdaExpr), nil
}
func (x *structLit) binOp(ctx *context, src source, op op, other evaluated) evaluated {
y, ok := other.(*structLit)
if !ok || op != opUnify {
return ctx.mkIncompatible(src, op, x, other)
}
// TODO: unify emit
x = ctx.deref(x).(*structLit)
y = ctx.deref(y).(*structLit)
if x == y {
return x
}
arcs := make(arcs, 0, len(x.arcs)+len(y.arcs))
obj := &structLit{binSrc(src.Pos(), op, x, other), x.emit, nil, nil, arcs, nil}
defer ctx.pushForwards(x, obj, y, obj).popForwards()
tx, ex := evalLambda(ctx, x.template)
ty, ey := evalLambda(ctx, y.template)
var t *lambdaExpr
switch {
case ex != nil:
return ex
case ey != nil:
return ey
case tx != nil:
t = tx
case ty != nil:
t = ty
}
if tx != ty && tx != nil && ty != nil {
v := binOp(ctx, src, opUnify, tx, ty)
if isBottom(v) {
return v
}
t = v.(*lambdaExpr)
}
if t != nil {
obj.template = ctx.copy(t)
}
sz := len(x.comprehensions) + len(y.comprehensions)
obj.comprehensions = make([]*fieldComprehension, sz)
for i, c := range x.comprehensions {
obj.comprehensions[i] = ctx.copy(c).(*fieldComprehension)
}
for i, c := range y.comprehensions {
obj.comprehensions[i+len(x.comprehensions)] = ctx.copy(c).(*fieldComprehension)
}
for _, a := range x.arcs {
cp := ctx.copy(a.v)
obj.arcs = append(obj.arcs,
arc{a.feature, a.optional, cp, nil, a.attrs, a.docs})
}
outer:
for _, a := range y.arcs {
v := ctx.copy(a.v)
for i, b := range obj.arcs {
if a.feature == b.feature {
v = mkBin(ctx, src.Pos(), opUnify, b.v, v)
obj.arcs[i].v = v
obj.arcs[i].cache = nil
obj.arcs[i].optional = a.optional && b.optional
obj.arcs[i].docs = mergeDocs(a.docs, b.docs)
attrs, err := unifyAttrs(ctx, src, a.attrs, b.attrs)
if err != nil {
return err
}
obj.arcs[i].attrs = attrs
continue outer
}
}
a.setValue(v)
obj.arcs = append(obj.arcs, a)
}
sort.Stable(obj)
return obj
}
func (x *nullLit) binOp(ctx *context, src source, op op, other evaluated) evaluated {
// TODO: consider using binSrc instead of src.base() for better traceability.
switch other.(type) {
case *nullLit:
switch op {
case opEql:
return &boolLit{baseValue: src.base(), b: true}
case opNeq:
return &boolLit{baseValue: src.base(), b: false}
case opUnify:
return x
}
case *bound:
// Not strictly necessary, but handling this results in better error
// messages.
if op == opUnify {
return other.binOp(ctx, src, opUnify, x)
}
default:
switch op {
case opEql:
return &boolLit{baseValue: src.base(), b: false}
case opNeq:
return &boolLit{baseValue: src.base(), b: true}
}
}
return ctx.mkIncompatible(src, op, x, other)
}
func (x *boolLit) binOp(ctx *context, src source, op op, other evaluated) evaluated {
switch y := other.(type) {
case *basicType:
// range math
return x
case *boolLit:
switch op {
case opUnify:
if x.b != y.b {
return ctx.mkErr(x, "conflicting values: %v != %v", x.b, y.b)
}
return x
case opLand:
return boolTonode(src, x.b && y.b)
case opLor:
return boolTonode(src, x.b || y.b)
case opEql:
return boolTonode(src, x.b == y.b)
case opNeq:
return boolTonode(src, x.b != y.b)
}
}
return ctx.mkIncompatible(src, op, x, other)
}
func (x *stringLit) binOp(ctx *context, src source, op op, other evaluated) evaluated {
switch y := other.(type) {
// case *basicType:
// return x
// TODO: rangelit
case *stringLit:
str := other.strValue()
switch op {
case opUnify:
str := other.strValue()
if x.str != str {
src := mkBin(ctx, src.Pos(), op, x, other)
return ctx.mkErr(src, "conflicting values: %v != %v", x.str, str)
}
return x
case opLss, opLeq, opEql, opNeq, opGeq, opGtr:
return cmpTonode(src, op, strings.Compare(x.str, str))
case opAdd:
src := binSrc(src.Pos(), op, x, other)
return &stringLit{src, x.str + str, nil}
case opMat:
if y.re == nil {
// This really should not happen, but leave in for safety.
b, err := regexp.MatchString(str, x.str)
if err != nil {
return ctx.mkErr(src, "error parsing regexp: %v", err)
}
return boolTonode(src, b)
}
return boolTonode(src, y.re.MatchString(x.str))
case opNMat:
if y.re == nil {
// This really should not happen, but leave in for safety.
b, err := regexp.MatchString(str, x.str)
if err != nil {
return ctx.mkErr(src, "error parsing regexp: %v", err)
}
return boolTonode(src, !b)
}
return boolTonode(src, !y.re.MatchString(x.str))
}
case *numLit:
switch op {
case opMul:
src := binSrc(src.Pos(), op, x, other)
return &stringLit{src, strings.Repeat(x.str, y.intValue(ctx)), nil}
}
}
return ctx.mkIncompatible(src, op, x, other)
}
func (x *bytesLit) binOp(ctx *context, src source, op op, other evaluated) evaluated {
switch y := other.(type) {
// case *basicType:
// return x
// TODO: rangelit
case *bytesLit:
b := y.b
switch op {
case opUnify:
if !bytes.Equal(x.b, b) {
return ctx.mkErr(x, "conflicting values: %v != %v", x.b, b)
}
return x
case opLss, opLeq, opEql, opNeq, opGeq, opGtr:
return cmpTonode(src, op, bytes.Compare(x.b, b))
case opAdd:
copy := append([]byte(nil), x.b...)
copy = append(copy, b...)
return &bytesLit{binSrc(src.Pos(), op, x, other), copy, nil}
}
case *numLit:
switch op {
case opMul:
src := binSrc(src.Pos(), op, x, other)
return &bytesLit{src, bytes.Repeat(x.b, y.intValue(ctx)), nil}
}
}
return ctx.mkIncompatible(src, op, x, other)
}
func test(ctx *context, src source, op op, a, b evaluated) bool {
v := binOp(ctx, src, op, a, b)
if isBottom(v) {
return false
}
return v.(*boolLit).b
}
func leq(ctx *context, src source, a, b evaluated) bool {
if isTop(a) || isTop(b) {
return true
}
v := binOp(ctx, src, opLeq, a, b)
if isBottom(v) {
return false
}
return v.(*boolLit).b
}
// TODO: should these go?
func maxNum(v value) value {
switch x := v.(type) {
case *numLit:
return x
case *bound:
switch x.op {
case opLeq:
return x.value
case opLss:
return &binaryExpr{x.baseValue, opSub, x.value, one}
}
return &basicType{x.baseValue, intKind}
}
return v
}
func minNum(v value) value {
switch x := v.(type) {
case *numLit:
return x
case *bound:
switch x.op {
case opGeq:
return x.value
case opGtr:
return &binaryExpr{x.baseValue, opAdd, x.value, one}
}
return &basicType{x.baseValue, intKind}
}
return v
}
func cmpTonode(src source, op op, r int) evaluated {
result := false
switch op {
case opLss:
result = r == -1
case opLeq:
result = r != 1
case opEql, opUnify:
result = r == 0
case opNeq:
result = r != 0
case opGeq:
result = r != -1
case opGtr:
result = r == 1
}
return boolTonode(src, result)
}
func (x *numLit) binOp(ctx *context, src source, op op, other evaluated) evaluated {
switch y := other.(type) {
case *basicType, *bound, *customValidator: // for better error reporting
if op == opUnify {
return y.binOp(ctx, src, op, x)
}
case *numLit:
k := unifyType(x.kind(), y.kind())
n := newNumBin(k, x, y)
switch op {
case opUnify:
if x.v.Cmp(&y.v) != 0 {
src = mkBin(ctx, src.Pos(), op, x, other)
return ctx.mkErr(src, "conflicting values: %v != %v", x.strValue(), y.strValue())
}
if k != x.k {
n.v = x.v
return n
}
return x
case opLss, opLeq, opEql, opNeq, opGeq, opGtr:
return cmpTonode(src, op, x.v.Cmp(&y.v))
case opAdd:
ctx.Add(&n.v, &x.v, &y.v)
case opSub:
ctx.Sub(&n.v, &x.v, &y.v)
case opMul:
ctx.Mul(&n.v, &x.v, &y.v)
case opQuo:
ctx.Quo(&n.v, &x.v, &y.v)
ctx.Reduce(&n.v, &n.v)
n.k = floatKind
case opRem:
ctx.Rem(&n.v, &x.v, &y.v)
n.k = floatKind
case opIDiv:
intOp(ctx, n, (*big.Int).Div, x, y)
case opIMod:
intOp(ctx, n, (*big.Int).Mod, x, y)
case opIQuo:
intOp(ctx, n, (*big.Int).Quo, x, y)
case opIRem:
intOp(ctx, n, (*big.Int).Rem, x, y)
}
return n
case *durationLit:
if op == opMul {
fd := float64(y.d)
// TODO: check range
f, _ := x.v.Float64()
d := time.Duration(f * fd)
return &durationLit{binSrc(src.Pos(), op, x, other), d}
}
}
return ctx.mkIncompatible(src, op, x, other)
}
type intFunc func(z, x, y *big.Int) *big.Int
func intOp(ctx *context, n *numLit, fn intFunc, a, b *numLit) {
var x, y apd.Decimal
ctx.RoundToIntegralValue(&x, &a.v)
if x.Negative {
x.Coeff.Neg(&x.Coeff)
}
ctx.RoundToIntegralValue(&y, &b.v)
if y.Negative {
y.Coeff.Neg(&y.Coeff)
}
fn(&n.v.Coeff, &x.Coeff, &y.Coeff)
if n.v.Coeff.Sign() < 0 {
n.v.Coeff.Neg(&n.v.Coeff)
n.v.Negative = true
}
n.k = intKind
}
// TODO: check overflow
func (x *durationLit) binOp(ctx *context, src source, op op, other evaluated) evaluated {
switch y := other.(type) {
case *basicType:
// infinity math
case *durationLit:
switch op {
case opUnify:
if x.d != y.d {
return ctx.mkIncompatible(src, op, x, other)
}
return other
case opLss:
return boolTonode(src, x.d < y.d)
case opLeq:
return boolTonode(src, x.d <= y.d)
case opEql:
return boolTonode(src, x.d == y.d)
case opNeq:
return boolTonode(src, x.d != y.d)
case opGeq:
return boolTonode(src, x.d >= y.d)
case opGtr:
return boolTonode(src, x.d > y.d)
case opAdd:
return &durationLit{binSrc(src.Pos(), op, x, other), x.d + y.d}
case opSub:
return &durationLit{binSrc(src.Pos(), op, x, other), x.d - y.d}
case opQuo:
n := &numLit{
numBase: newNumBase(nil, newNumInfo(floatKind, 0, 10, false)),
}
n.v.SetInt64(int64(x.d))
d := apd.New(int64(y.d), 0)
ctx.Quo(&n.v, &n.v, d)
return n
case opRem:
n := &numLit{
numBase: newNumBase(nil, newNumInfo(intKind, 0, 10, false)),
}
n.v.SetInt64(int64(x.d % y.d))
n.v.Exponent = -9
return n
}
case *numLit:
switch op {
case opMul:
// TODO: check range
f, _ := y.v.Float64()
d := time.Duration(float64(x.d) * f)
return &durationLit{binSrc(src.Pos(), op, x, other), d}
case opQuo:
// TODO: check range
f, _ := y.v.Float64()
d := time.Duration(float64(x.d) * f)
return &durationLit{binSrc(src.Pos(), op, x, other), d}
case opRem:
d := x.d % time.Duration(y.intValue(ctx))
return &durationLit{binSrc(src.Pos(), op, x, other), d}
}
}
return ctx.mkIncompatible(src, op, x, other)
}
func (x *list) binOp(ctx *context, src source, op op, other evaluated) evaluated {
switch op {
case opUnify:
y, ok := other.(*list)
if !ok {
break
}
n := unify(ctx, src, x.len.(evaluated), y.len.(evaluated))
if isBottom(n) {
src = mkBin(ctx, src.Pos(), op, x, other)
return ctx.mkErr(src, "incompatible list lengths: %v", n)
}
sx := x.elem.arcs
xa := sx
sy := y.elem.arcs
ya := sy
for len(xa) < len(ya) {
xa = append(xa, arc{feature: label(len(xa)), v: x.typ})
}
for len(ya) < len(xa) {
ya = append(ya, arc{feature: label(len(ya)), v: y.typ})
}
typ := x.typ
max, ok := n.(*numLit)
if !ok || len(xa) < max.intValue(ctx) {
typ = unify(ctx, src, x.typ.(evaluated), y.typ.(evaluated))
if isBottom(typ) {
src = mkBin(ctx, src.Pos(), op, x, other)
return ctx.mkErr(src, "incompatible list types: %v: ", typ)
}
}
// TODO: use forwarding instead of this mild hack.
x.elem.arcs = xa
y.elem.arcs = ya
s := unify(ctx, src, x.elem, y.elem).(*structLit)
x.elem.arcs = sx
y.elem.arcs = sy
base := binSrc(src.Pos(), op, x, other)
return &list{baseValue: base, elem: s, typ: typ, len: n}
case opEql, opNeq:
y, ok := other.(*list)
if !ok {
break
}
if len(x.elem.arcs) != len(y.elem.arcs) {
return boolTonode(src, false)
}
for i := range x.elem.arcs {
if !test(ctx, src, op, x.at(ctx, i), y.at(ctx, i)) {
return boolTonode(src, false)
}
}
return boolTonode(src, true)
case opAdd:
y, ok := other.(*list)
if !ok {
break
}
n := &list{baseValue: binSrc(src.Pos(), op, x, other), typ: y.typ}
arcs := []arc{}
for _, v := range x.elem.arcs {
arcs = append(arcs, arc{feature: label(len(arcs)), v: v.v})
}
for _, v := range y.elem.arcs {
arcs = append(arcs, arc{feature: label(len(arcs)), v: v.v})
}
switch v := y.len.(type) {
case *numLit:
// Closed list
ln := &numLit{numBase: v.numBase}
ln.v.SetInt64(int64(len(arcs)))
n.len = ln
default:
// Open list
n.len = y.len // TODO: add length of x?
}
n.elem = &structLit{baseValue: n.baseValue, arcs: arcs}
return n
case opMul:
k := other.kind()
if !k.isAnyOf(intKind) {
panic("multiplication must be int type")
}
n := &list{baseValue: binSrc(src.Pos(), op, x, other), typ: x.typ}
arcs := []arc{}
if len(x.elem.arcs) > 0 {
if !k.isGround() {
// should never reach here.
break
}
if ln := other.(*numLit).intValue(ctx); ln > 0 {
for i := 0; i < ln; i++ {
// TODO: copy values
for _, a := range x.elem.arcs {
arcs = append(arcs, arc{feature: label(len(arcs)), v: a.v})
}
}
} else if ln < 0 {
return ctx.mkErr(src, "negative number %d multiplies list", ln)
}
}
switch v := x.len.(type) {
case *numLit:
// Closed list
ln := &numLit{numBase: v.numBase}
ln.v.SetInt64(int64(len(arcs)))
n.len = ln
default:
// Open list
n.len = x.len // TODO: multiply length?
}
n.elem = &structLit{baseValue: n.baseValue, arcs: arcs}
return n
}
return ctx.mkIncompatible(src, op, x, other)
}
func (x *lambdaExpr) binOp(ctx *context, src source, op op, other evaluated) evaluated {
if y, ok := other.(*lambdaExpr); ok && op == opUnify {
x = ctx.deref(x).(*lambdaExpr)
y = ctx.deref(y).(*lambdaExpr)
n, m := len(x.params.arcs), len(y.params.arcs)
if n != m {
src = mkBin(ctx, src.Pos(), op, x, other)
return ctx.mkErr(src, "number of params should match (%d != %d)", n, m)
}
arcs := make([]arc, len(x.arcs))
lambda := &lambdaExpr{binSrc(src.Pos(), op, x, other), &params{arcs}, nil}
defer ctx.pushForwards(x, lambda, y, lambda).popForwards()
xVal := ctx.copy(x.value)
yVal := ctx.copy(y.value)
lambda.value = mkBin(ctx, src.Pos(), opUnify, xVal, yVal)
for i := range arcs {
xArg := ctx.copy(x.at(ctx, i)).(evaluated)
yArg := ctx.copy(y.at(ctx, i)).(evaluated)
v := binOp(ctx, src, op, xArg, yArg)
if isBottom(v) {
return v
}
arcs[i] = arc{feature: x.arcs[i].feature, v: v}
}
return lambda
}
return ctx.mkIncompatible(src, op, x, other)
}
func (x *builtin) binOp(ctx *context, src source, op op, other evaluated) evaluated {
if op == opUnify && evaluated(x) == other {
return x
}
return ctx.mkIncompatible(src, op, x, other)
}
func (x *feed) binOp(ctx *context, src source, op op, other evaluated) evaluated {
return ctx.mkIncompatible(src, op, x, other)
}
func (x *guard) binOp(ctx *context, src source, op op, other evaluated) evaluated {
return ctx.mkIncompatible(src, op, x, other)
}
func (x *yield) binOp(ctx *context, src source, op op, other evaluated) evaluated {
return ctx.mkIncompatible(src, op, x, other)
}
func (x *fieldComprehension) binOp(ctx *context, src source, op op, other evaluated) evaluated {
return ctx.mkIncompatible(src, op, x, other)
}