// File.Push 接收扫描到的 Token,
func (b *File) Push(pos scanner.Pos, tok token.Token, code string) error {
var flag Flag
switch tok {
case token.NL:
flag = FText
last := b.Last.Token()
if last == token.NL {
tok = token.EMPTYLINE // 转
break
}
if last == token.INDENTATION ||
last == token.EMPTYLINE {
text := b.Last.(*Text)
text.Source += code
text.Tok = token.EMPTYLINE // 合并
return nil
}
last = b.Active.Token()
if last == token.RIGHT || last == token.IDENT ||
last.As(token.Literal) {
err := b.Active.Final()
if err != nil {
return err
}
flag |= FFinal
}
// 识别 Python 缩进风格
case token.RIGHT:
case token.COMMENT, token.COMMENTS:
flag = FText
if b.Last.Token() == token.EMPTYLINE ||
b.Last.Token() == token.PLACEHOLDER {
tok = token.PLACEHOLDER // 转
break
}
// 先不使用合并
tok = token.COMMENT
case token.PLACEHOLDER, token.INDENTATION:
// 统一处理右括号闭合
flag = FText
default:
if tok > token.PLACEHOLDER || b.Active.Kind(FFile|FBlock|FText) != 0 {
return errors.New("ast: Oop! invalid " + tok.String())
}
if b.expect != nil {
// expect 尝试生成 Text 节点, 并且 tok 不变
if _, pass := b.expect.Eat(tok); pass {
flag = FText
b.expect = nil
break
}
b.expect = nil
}
base := Base{
Tok: tok,
Pos: pos,
Source: code,
}
b.Active.resolve(&base)
if base.Flag == 0 {
return errors.New("ast: Oop! invalid " + tok.String())
}
return b.add(base)
case token.EOF:
// 最后的闭合检查
}
if flag == 0 {
return errors.New("ast: Oop! invalid " + tok.String())
}
return b.add(Base{
Flag: flag,
Tok: tok,
Pos: pos,
Source: code,
})
}
