cue/format: don't indent fields on same line as lbrace

Vertical tabs are inserted after struct fields in order to correctly
vertically align values via text/tabwriter.

A recent CL https://cuelang.org/cl/1170966 made changes to this logic
in order to improve indentation of list elements.
As part of this change, a field whose value is a binary expression will
no longer have a vertical tab inserted.
For example, given the following code:

    x: 1
    foo: bar & {baz: 1}

The formatter will insert vertical tabs like so:

    x:<VT>1
    foo: bar & {baz:<VT>1}

Which means text/tabwriter will output the following:

    x:               1
    foo: bar & {baz: 1}

The logic is fixed to now ensure that no vtabs are inserted in a line
once an '{' has been written, so that vertical tabs in the above example
will now be inserted like this:

    x:<VT>1
    foo: bar & {baz: 1}

And the formatted code will now be:

    x: 1
    foo: bar & {baz: 1}

In addition, a few typos were fixed and dead code was removed.

Fixes #3015

Signed-off-by: Noam Dolovich <noam.tzvi.dolovich@gmail.com>
Change-Id: Ibee8ffc617324396523b50a4bb30b9cfc8beb28c
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1193515
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Unity-Result: CUE porcuepine <cue.porcuepine@gmail.com>
TryBot-Result: CUEcueckoo <cueckoo@cuelang.org>

cue/format/format.go

@@ -262,13 +262,6 @@ func (f *formatter) formfeed() whiteSpace {
 	return formfeed
 }
 
-func (f *formatter) wsOverride(def whiteSpace) whiteSpace {
-	if f.current.override == ignore {
-		return def
-	}
-	return f.current.override
-}
-
 func (f *formatter) onOneLine(node ast.Node) bool {
 	a := node.Pos()
 	b := node.End()

cue/format/format_test.go

@@ -229,7 +229,7 @@ func init() {
 	}
 }
 
-// TestNodes tests nodes that are that are invalid CUE, but are accepted by
+// TestNodes tests nodes that are invalid CUE, but are accepted by
 // format.
 func TestNodes(t *testing.T) {
 	testCases := []struct {

cue/format/node.go

@@ -235,7 +235,7 @@ func (f *formatter) inlineField(n *ast.Field) *ast.Field {
 	regular := internal.IsRegularField(n)
 	// shortcut single-element structs.
 	// If the label has a valid position, we assume that an unspecified
-	// Lbrace signals the intend to collapse fields.
+	// Lbrace signals the intent to collapse fields.
 	if !n.Label.Pos().IsValid() && !(f.printer.cfg.simplify && regular) {
 		return nil
 	}
@@ -304,7 +304,7 @@ func (f *formatter) decl(decl ast.Decl) {
 
 		nextFF := f.nextNeedsFormfeed(n.Value)
 		tab := vtab
-		if nextFF {
+		if nextFF || f.prevLbraceOnLine {
 			tab = blank
 		}
 
@@ -645,6 +645,7 @@ func (f *formatter) exprRaw(expr ast.Expr, prec1, depth int) {
 			ws |= newline | nooverride
 		}
 		f.print(x.Lbrace, token.LBRACE, &l, ws, ff, indent)
+		f.prevLbraceOnLine = l == f.lineout
 
 		f.walkDeclList(x.Elts)
 		f.matchUnindent()
@@ -849,7 +850,7 @@ func (f *formatter) binaryExpr(x *ast.BinaryExpr, prec1, cutoff, depth int) {
 	prec := x.Op.Precedence()
 	if prec < prec1 {
 		// parenthesis needed
-		// Note: The parser inserts an syntax.ParenExpr node; thus this case
+		// Note: The parser inserts a syntax.ParenExpr node; thus this case
 		//       can only occur if the AST is created in a different way.
 		// defer p.pushComment(nil).pop()
 		f.print(token.LPAREN, nooverride)

cue/format/printer.go

@@ -41,9 +41,10 @@ type printer struct {
 
 	lastTok token.Token // last token printed (syntax.ILLEGAL if it's whitespace)
 
-	output      []byte
-	indent      int
-	spaceBefore bool
+	output           []byte
+	indent           int
+	spaceBefore      bool
+	prevLbraceOnLine bool // true if a '{' has been written on the current line
 
 	errs errors.Error
 }
@@ -269,17 +270,17 @@ func (p *printer) writeWhitespace(ws whiteSpace) {
 	case ws&newsection != 0:
 		p.maybeIndentLine(ws)
 		p.writeByte('\f', 2)
-		p.lineout += 2
+		p.incrementLine(2)
 		p.spaceBefore = true
 	case ws&formfeed != 0:
 		p.maybeIndentLine(ws)
 		p.writeByte('\f', 1)
-		p.lineout++
+		p.incrementLine(1)
 		p.spaceBefore = true
 	case ws&newline != 0:
 		p.maybeIndentLine(ws)
 		p.writeByte('\n', 1)
-		p.lineout++
+		p.incrementLine(1)
 		p.spaceBefore = true
 	case ws&declcomma != 0:
 		p.writeByte(',', 1)
@@ -295,6 +296,13 @@ func (p *printer) writeWhitespace(ws whiteSpace) {
 	}
 }
 
+func (p *printer) incrementLine(n int) {
+	if n != 0 {
+		p.prevLbraceOnLine = false
+	}
+	p.lineout += line(n)
+}
+
 func (p *printer) markLineIndent(ws whiteSpace) {
 	p.indentStack = append(p.indentStack, ws)
 }

cue/format/testdata/expressions.golden

@@ -270,12 +270,12 @@ import "list"
 	o: [{}]
 	o: [{}]
 
-	p:         1
+	p: 1
 	p: p & {p: 2}
-	q:         1
+	q: 1
 	q: q | {q: 2}
-	r:                1
+	r: 1
 	r: b & [1, 2, {a: 4}]
 	s: [string]: [string]: a
-	s: [string]: {s:       string}
+	s: [string]: {s: string}
 }

cue/token/position.go

@@ -149,7 +149,7 @@ func (p RelPos) Pos() Pos {
 	return Pos{nil, int(p)}
 }
 
-// HasRelPos repors whether p has a relative position.
+// HasRelPos reports whether p has a relative position.
 func (p Pos) HasRelPos() bool {
 	return p.offset&relMask != 0
 

encoding/protobuf/testdata/istio.io/api/cue.mod/gen/github.com/golang/protobuf/protoc-gen-go/descriptor/descriptor_proto_gen.cue

@@ -153,17 +153,17 @@ package descriptor
 		// 0 is reserved for errors.
 		// Order is weird for historical reasons.
 		"TYPE_DOUBLE"
-					#enumValue: 1
+		#enumValue: 1
 	} | {"TYPE_FLOAT", #enumValue: 2} | {
 		// Not ZigZag encoded.  Negative numbers take 10 bytes.  Use TYPE_SINT64 if
 		// negative values are likely.
 		"TYPE_INT64"
-					#enumValue: 3
+		#enumValue: 3
 	} | {"TYPE_UINT64", #enumValue: 4} | {
 		// Not ZigZag encoded.  Negative numbers take 10 bytes.  Use TYPE_SINT32 if
 		// negative values are likely.
 		"TYPE_INT32"
-						#enumValue: 5
+		#enumValue: 5
 	} | {"TYPE_FIXED64", #enumValue: 6} |
 		{"TYPE_FIXED32", #enumValue: 7} |
 		{"TYPE_BOOL", #enumValue: 8} |
@@ -180,7 +180,7 @@ package descriptor
 		} | {
 			// New in version 2.
 			"TYPE_BYTES"
-						#enumValue: 12
+			#enumValue: 12
 		} | {"TYPE_UINT32", #enumValue: 13} |
 		{"TYPE_ENUM", #enumValue: 14} |
 		{"TYPE_SFIXED32", #enumValue: 15} |
@@ -216,7 +216,7 @@ package descriptor
 	#Label: {
 		// 0 is reserved for errors
 		"LABEL_OPTIONAL"
-						#enumValue: 1
+		#enumValue: 1
 	} | {"LABEL_REQUIRED", #enumValue: 2} |
 		{"LABEL_REPEATED", #enumValue: 3}
 
@@ -518,7 +518,7 @@ package descriptor
 	#CType: {
 		// Default mode.
 		"STRING"
-					#enumValue: 0
+		#enumValue: 0
 	} | {"CORD", #enumValue: 1} |
 		{"STRING_PIECE", #enumValue: 2}