cue/...: remove remnants of /*block*/ comment support

https://cue-review.googlesource.com/c/cue/+/3983 and later
https//cuelang.org/cl/547012 meant to fully remove support for
block comments as explained in https://cuelang.org/issue/87,
but the documentation and bits of code and tests were left behind.

Note that tools/fix rewriting block comments as line comments
has been untested and broken since the two CLs above in 2019.
Given the amount of time that has passed, remove the fix code as well.

Signed-off-by: Daniel Martí <mvdan@mvdan.cc>
Change-Id: I8ade2b2461c665de1fd54d09e11cbfbf4a1d03a4
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1196133
Reviewed-by: Aram Hăvărneanu <aram@cue.works>
TryBot-Result: CUEcueckoo <cueckoo@cuelang.org>
Unity-Result: CUE porcuepine <cue.porcuepine@gmail.com>

cue/ast/ast.go

@@ -176,10 +176,10 @@ func (c *comments) SetComments(cgs []*CommentGroup) {
 	*c.groups = cgs
 }
 
-// A Comment node represents a single //-style or /*-style comment.
+// A Comment node represents a single //-style comment.
 type Comment struct {
 	Slash token.Pos // position of "/" starting the comment
-	Text  string    // comment text (excluding '\n' for //-style comments)
+	Text  string    // comment text excluding '\n'
 }
 
 func (c *Comment) Comments() []*CommentGroup { return nil }
@@ -226,7 +226,7 @@ func stripTrailingWhitespace(s string) string {
 }
 
 // Text returns the text of the comment.
-// Comment markers (//, /*, and */), the first space of a line comment, and
+// Comment markers ("//"), the first space of a line comment, and
 // leading and trailing empty lines are removed. Multiple empty lines are
 // reduced to one, and trailing space on lines is trimmed. Unless the result
 // is empty, it is newline-terminated.
@@ -243,17 +243,10 @@ func (g *CommentGroup) Text() string {
 	for _, c := range comments {
 		// Remove comment markers.
 		// The parser has given us exactly the comment text.
-		switch c[1] {
-		case '/':
-			//-style comment (no newline at the end)
-			c = c[2:]
-			// strip first space - required for Example tests
-			if len(c) > 0 && c[0] == ' ' {
-				c = c[1:]
-			}
-		case '*':
-			/*-style comment */
-			c = c[2 : len(c)-2]
+		c = c[2:]
+		// strip first space - required for Example tests
+		if len(c) > 0 && c[0] == ' ' {
+			c = c[1:]
 		}
 
 		// Split on newlines.

cue/ast/ast_test.go

@@ -41,19 +41,7 @@ func TestCommentText(t *testing.T) {
 		{[]string{"// foo  bar  "}, "foo  bar\n"},
 		{[]string{"// foo", "// bar"}, "foo\nbar\n"},
 		{[]string{"// foo", "//", "//", "//", "// bar"}, "foo\n\nbar\n"},
-		{[]string{"// foo", "/* bar */"}, "foo\n bar\n"},
 		{[]string{"//", "//", "//", "// foo", "//", "//", "//"}, "foo\n"},
-
-		{[]string{"/**/"}, ""},
-		{[]string{"/*   */"}, ""},
-		{[]string{"/**/", "/**/", "/*   */"}, ""},
-		{[]string{"/* Foo   */"}, " Foo\n"},
-		{[]string{"/* Foo  Bar  */"}, " Foo  Bar\n"},
-		{[]string{"/* Foo*/", "/* Bar*/"}, " Foo\n Bar\n"},
-		{[]string{"/* Foo*/", "/**/", "/**/", "/**/", "// Bar"}, " Foo\n\nBar\n"},
-		{[]string{"/* Foo*/", "/*\n*/", "//", "/*\n*/", "// Bar"}, " Foo\n\nBar\n"},
-		{[]string{"/* Foo*/", "// Bar"}, " Foo\nBar\n"},
-		{[]string{"/* Foo\n Bar*/"}, " Foo\n Bar\n"},
 	}
 
 	for i, c := range testCases {

cue/format/format.go

@@ -25,7 +25,6 @@ package format
 import (
 	"bytes"
 	"fmt"
-	"strings"
 	"text/tabwriter"
 
 	"cuelang.org/go/cue/ast"
@@ -320,22 +319,15 @@ func (f *formatter) printComment(cg *ast.CommentGroup) {
 		printBlank = true
 	}
 	for _, c := range cg.List {
-		isEnd := strings.HasPrefix(c.Text, "//")
 		if !printBlank {
-			if isEnd {
-				f.Print(vtab)
-			} else {
-				f.Print(blank)
-			}
+			f.Print(vtab)
 		}
 		f.Print(c.Slash)
 		f.Print(c)
-		if isEnd {
-			f.printingComment = true
-			f.Print(newline)
-			if cg.Doc {
-				f.Print(nooverride)
-			}
+		f.printingComment = true
+		f.Print(newline)
+		if cg.Doc {
+			f.Print(nooverride)
 		}
 	}
 }

cue/parser/parser.go

@@ -274,19 +274,7 @@ func (p *parser) next0() {
 
 // Consume a comment and return it and the line on which it ends.
 func (p *parser) consumeComment() (comment *ast.Comment, endline int) {
-	// /*-style comments may end on a different line than where they start.
-	// Scan the comment for '\n' chars and adjust endline accordingly.
 	endline = p.file.Line(p.pos)
-	if p.lit[1] == '*' {
-		p.assertV0(p.pos, 0, 10, "block quotes")
-
-		// don't use range here - no need to decode Unicode code points
-		for i := 0; i < len(p.lit); i++ {
-			if p.lit[i] == '\n' {
-				endline++
-			}
-		}
-	}
 
 	comment = &ast.Comment{Slash: p.pos, Text: p.lit}
 	p.next0()

tools/fix/fix.go

@@ -20,8 +20,6 @@
 package fix
 
 import (
-	"strings"
-
 	"cuelang.org/go/cue/ast"
 	"cuelang.org/go/cue/ast/astutil"
 	"cuelang.org/go/cue/token"
@@ -64,39 +62,6 @@ func File(f *ast.File, o ...Option) *ast.File {
 		return true
 	}, nil).(*ast.File)
 
-	// Rewrite block comments to regular comments.
-	ast.Walk(f, func(n ast.Node) bool {
-		switch x := n.(type) {
-		case *ast.CommentGroup:
-			comments := []*ast.Comment{}
-			for _, c := range x.List {
-				s := c.Text
-				if !strings.HasPrefix(s, "/*") || !strings.HasSuffix(s, "*/") {
-					comments = append(comments, c)
-					continue
-				}
-				if x.Position > 0 {
-					// Moving to the end doesn't work, as it still
-					// may inject at a false line break position.
-					x.Position = 0
-					x.Doc = true
-				}
-				s = strings.TrimSpace(s[2 : len(s)-2])
-				for _, s := range strings.Split(s, "\n") {
-					for i := 0; i < 3; i++ {
-						if strings.HasPrefix(s, " ") || strings.HasPrefix(s, "*") {
-							s = s[1:]
-						}
-					}
-					comments = append(comments, &ast.Comment{Text: "// " + s})
-				}
-			}
-			x.List = comments
-			return false
-		}
-		return true
-	}, nil)
-
 	// TODO: we are probably reintroducing slices. Disable for now.
 	//
 	// Rewrite slice expression.