cue: don't print definitions in concrete mode

it is especially important to omit them when
printing data.

Issue #40

Change-Id: Ib6ce21cbaf4987d43036605b0e2fa3a62ec2ef63
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/2873
Reviewed-by: Marcel van Lohuizen <[email protected]>

Author: mpvl

cmd/cue/cmd/testdata/export/export.cue

@@ -1,6 +1,8 @@
 package export
 
-def: *1 | int
+One :: 1
+
+def: *One | int
 
 a: string
 a: "foo"

cmd/cue/cmd/testdata/hello/data.cue

@@ -1,3 +1,3 @@
 package hello
 
-who: "World"
+who :: "World"

cmd/cue/cmd/testdata/hello/eval.out

@@ -1,2 +1,2 @@
-who:     "World"
+who ::   "World"
 message: "Hello World!"

cmd/cue/cmd/testdata/hello/eval_conc.out

@@ -1,2 +1 @@
-who:     "World"
 message: "Hello World!"

cmd/cue/cmd/testdata/hello/export.out

@@ -1,4 +1,3 @@
 {
-    "who": "World",
     "message": "Hello World!"
 }

cue/export.go

@@ -621,6 +621,9 @@ func (p *exporter) structure(x *structLit, addTempl bool) (ret *ast.StructLit, e
 			f.Optional = token.NoSpace.Pos()
 		}
 		if a.definition {
+			if p.mode.omitHidden || p.mode.concrete {
+				continue
+			}
 			f.Token = token.ISA
 		}
 		if a.feature&hidden != 0 && p.mode.concrete && p.mode.omitHidden {

cue/format/node.go

@@ -173,7 +173,7 @@ func (f *formatter) decl(decl ast.Decl) {
 		if lastSize != len(f.labelBuf) {
 			f.print(formfeed)
 		}
-		if !regular && first.Pos().RelPos() < token.Newline {
+		if !regular && first.Pos().RelPos() < token.Newline && len(f.output) > 0 {
 			f.print(newline, nooverride)
 		}
 

cue/types.go

@@ -1060,8 +1060,13 @@ func (v Value) structValOpts(ctx *context, o options) (structValue, *bottom) {
 		f := label(0)
 		for _, a := range obj.arcs {
 			f |= a.feature
-			if o.omitOptional && a.optional {
+			if a.optional && o.omitOptional {
+				needFilter = true
+				break
+			}
+			if a.definition && (o.omitHidden || o.concrete) {
 				needFilter = true
+				break
 			}
 		}
 		needFilter = needFilter || f&hidden != 0
@@ -1071,10 +1076,17 @@ func (v Value) structValOpts(ctx *context, o options) (structValue, *bottom) {
 		arcs := make([]arc, len(obj.arcs))
 		k := 0
 		for _, a := range obj.arcs {
-			if a.feature&hidden == 0 && !a.optional {
-				arcs[k] = a
-				k++
+			if a.definition && (o.omitHidden || o.concrete) {
+				continue
+			}
+			if a.feature&hidden != 0 && o.omitHidden {
+				continue
+			}
+			if o.omitOptional && a.optional {
+				continue
 			}
+			arcs[k] = a
+			k++
 		}
 		arcs = arcs[:k]
 		obj = &structLit{