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proc: Short circuit evaluation of && and || like go does

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Change evaluation of binary operators so that both && and || only
evaluate their second argument conditionally, like go does.
This commit is contained in:
aarzilli 2018-04-13 19:05:55 +02:00 committed by Derek Parker
parent e1f2626b56
commit b9c4a1d68c
3 changed files with 23 additions and 8 deletions
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4
_fixtures/testvariables2.go
View File

@ -244,6 +244,8 @@ func main() {
longstr := "very long string 0123456789a0123456789b0123456789c0123456789d0123456789e0123456789f0123456789g012345678h90123456789i0123456789j0123456789"
var nilstruct *astruct = nil
var amb1 = 1
runtime.Breakpoint()
for amb1 := 0; amb1 < 10; amb1++ {
@ -251,5 +253,5 @@ func main() {
}
runtime.Breakpoint()
fmt.Println(i1, i2, i3, p1, amb1, s1, s3, a1, p2, p3, s2, as1, str1, f1, fn1, fn2, nilslice, nilptr, ch1, chnil, m1, mnil, m2, m3, up1, i4, i5, i6, err1, err2, errnil, iface1, iface2, ifacenil, arr1, parr, cpx1, const1, iface3, iface4, recursive1, recursive1.x, iface5, iface2fn1, iface2fn2, bencharr, benchparr, mapinf, mainMenu, b, b2, sd, anonstruct1, anonstruct2, anoniface1, anonfunc, mapanonstruct1, ifacearr, efacearr, ni8, ni16, ni32, pinf, ninf, nan, zsvmap, zsslice, zsvar, tm, errtypednil, emptyslice, emptymap, byteslice, runeslice, longstr)
fmt.Println(i1, i2, i3, p1, amb1, s1, s3, a1, p2, p3, s2, as1, str1, f1, fn1, fn2, nilslice, nilptr, ch1, chnil, m1, mnil, m2, m3, up1, i4, i5, i6, err1, err2, errnil, iface1, iface2, ifacenil, arr1, parr, cpx1, const1, iface3, iface4, recursive1, recursive1.x, iface5, iface2fn1, iface2fn2, bencharr, benchparr, mapinf, mainMenu, b, b2, sd, anonstruct1, anonstruct2, anoniface1, anonfunc, mapanonstruct1, ifacearr, efacearr, ni8, ni16, ni32, pinf, ninf, nan, zsvmap, zsslice, zsvar, tm, errtypednil, emptyslice, emptymap, byteslice, runeslice, longstr, nilstruct)
}

23
pkg/proc/eval.go
View File

@ -931,19 +931,28 @@ func (scope *EvalScope) evalBinary(node *ast.BinaryExpr) (*Variable, error) {
if err != nil {
return nil, err
}
xv.loadValue(loadFullValue)
if xv.Unreadable != nil {
return nil, xv.Unreadable
}
// short circuits logical operators
switch node.Op {
case token.LAND:
if !constant.BoolVal(xv.Value) {
return newConstant(xv.Value, xv.mem), nil
}
case token.LOR:
if constant.BoolVal(xv.Value) {
return newConstant(xv.Value, xv.mem), nil
}
}
yv, err := scope.evalAST(node.Y)
if err != nil {
return nil, err
}
xv.loadValue(loadFullValue)
yv.loadValue(loadFullValue)
if xv.Unreadable != nil {
return nil, xv.Unreadable
}
if yv.Unreadable != nil {
return nil, yv.Unreadable
}

4
service/test/variables_test.go
View File

@ -735,6 +735,10 @@ func TestEvalExpression(t *testing.T) {
{"ch1.dataqsiz", false, "10", "10", "uint", nil},
{"ch1.buf", false, `*[10]int [1,4,3,2,0,0,0,0,0,0]`, `(*[10]int)(…`, "*[10]int", nil},
{"ch1.buf[0]", false, "1", "1", "int", nil},
// shortcircuited logical operators
{"nilstruct != nil && nilstruct.A == 1", false, "false", "false", "", nil},
{"nilstruct == nil || nilstruct.A == 1", false, "true", "true", "", nil},
}
ver, _ := goversion.Parse(runtime.Version())