cmd/cue: ignore complex types in get go

Complex numbers have no opaque representation in Go. The real and
imaginary parts of a complex number are only accessible using the
inbuilt functions real and imag. There is also no agreed upon standard
for representing complex numbers in other data formats like JSON or
YAML. Most encoders will simply write strings in the form "1+2i". I
think the safest thing to do for now is to represent complex numbers
with top, and adjust this in future if needed.

Fixes #2661

Change-Id: Ibdcbf04a535490a4936323b37c79eec12bbd822c
Signed-off-by: Thomas Way <[email protected]>
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1170115
Unity-Result: CUE porcuepine <[email protected]>
Reviewed-by: Daniel Martí <[email protected]>
TryBot-Result: CUEcueckoo <[email protected]>

Author: uhthomas

cmd/cue/cmd/get_go.go

@@ -1187,9 +1187,10 @@ func (e *extractor) makeType(expr types.Type) (result cueast.Expr) {
 			return e.ident("uint64", false)
 		case types.Byte:
 			return e.ident("uint8", false)
-		default:
-			return e.ident(x.String(), false)
+		case types.Complex64, types.Complex128:
+			return e.ident("_", false)
 		}
+		return e.ident(x.String(), false)
 
 	case *types.Union:
 		var exprs []cueast.Expr

cmd/cue/cmd/testdata/script/get_go_types.txtar

@@ -44,6 +44,7 @@ import (
 	"encoding"
 	"encoding/json"
 	"time"
+	"unsafe"
 
 	p2 "mod.test/pkg2"
 )
@@ -67,6 +68,11 @@ type Foozer struct {
 
 	Ptr uintptr
 
+	UnsafePointer unsafe.Pointer
+
+	Complex64     complex64
+	Complex128    complex128
+
 	Byte byte
 
 	// Time is mapped to CUE's internal type.
@@ -248,14 +254,17 @@ import (
 	String: string
 
 	#Inline
-	NoInline:    #NoInline
-	CustomJSON:  #CustomJSON
-	CustomYAML?: null | #CustomYAML @go(,*CustomYAML)
-	AnyJSON:     _                  @go(,json.Marshaler)
-	AnyText:     string             @go(,encoding.TextMarshaler)
-	bar?:        int & >10          @go(Bar)
-	Ptr:         uint64             @go(,uintptr)
-	Byte:        uint8              @go(,byte)
+	NoInline:      #NoInline
+	CustomJSON:    #CustomJSON
+	CustomYAML?:   null | #CustomYAML @go(,*CustomYAML)
+	AnyJSON:       _                  @go(,json.Marshaler)
+	AnyText:       string             @go(,encoding.TextMarshaler)
+	bar?:          int & >10          @go(Bar)
+	Ptr:           uint64             @go(,uintptr)
+	UnsafePointer: uint64             @go(,unsafe.Pointer)
+	Complex64:     _                  @go(,complex64)
+	Complex128:    _                  @go(,complex128)
+	Byte:          uint8              @go(,byte)
 
 	// Time is mapped to CUE's internal type.
 	Time:    time.Time