// intersperseComments consumes all comments that appear before the next token
// tok and prints it together with the buffered whitespace (i.e., the whitespace
// that needs to be written before the next token). A heuristic is used to mix
// the comments and whitespace. intersperseComments returns true if a pending
// formfeed was dropped from the whitespace buffer.
//
func (p *printer) intersperseComments(next token.Position, tok token.Token) (droppedFF bool) {
var last *ast.Comment
for ; p.commentBefore(next); p.cindex++ {
for _, c := range p.comments[p.cindex].List {
p.writeCommentPrefix(p.fset.Position(c.Pos()), next, last, tok.IsKeyword())
p.writeComment(c)
last = c
}
}
if last != nil {
if last.Text[1] == '*' && p.fset.Position(last.Pos()).Line == next.Line {
// the last comment is a /*-style comment and the next item
// follows on the same line: separate with an extra blank
p.write([]byte{' '})
}
// ensure that there is a line break after a //-style comment,
// before a closing '}' unless explicitly disabled, or at eof
needsLinebreak :=
last.Text[1] == '/' ||
tok == token.RBRACE && p.mode&noExtraLinebreak == 0 ||
tok == token.EOF
return p.writeCommentSuffix(needsLinebreak)
}
// no comment was written - we should never reach here since
// intersperseComments should not be called in that case
p.internalError("intersperseComments called without pending comments")
return false
}
func (p *parser) expect(tok token.Token) token.Pos {
pos := p.pos
if p.tok != tok {
p.errorExpected(pos, "'"+tok.String()+"'")
}
p.next() // make progress
return pos
}
func (p *parser) parseGenDecl(keyword token.Token, f parseSpecFunction) *ast.GenDecl {
if p.trace {
defer un(trace(p, "GenDecl("+keyword.String()+")"))
}
doc := p.leadComment
pos := p.expect(keyword)
var lparen, rparen token.Pos
var list []ast.Spec
if p.tok == token.LPAREN {
lparen = p.pos
p.next()
for p.tok != token.RPAREN && p.tok != token.EOF {
list = append(list, f(p, p.leadComment))
}
rparen = p.expect(token.RPAREN)
p.expectSemi()
} else {
list = append(list, f(p, nil))
}
return &ast.GenDecl{doc, pos, keyword, lparen, list, rparen}
}
func tokenclass(tok token.Token) int {
switch {
case tok.IsLiteral():
return literal
case tok.IsOperator():
return operator
case tok.IsKeyword():
return keyword
}
return special
}