package ast import ( `fmt` `strings` `unsafe` `github.com/bytedance/sonic/internal/native/types` ) func (self *Parser) syntaxError(err types.ParsingError) SyntaxError { return SyntaxError{ Pos : self.p, Src : self.s, Code: err, } } func newSyntaxError(err SyntaxError) *Node { msg := err.Description() return &Node{ t: V_ERROR, v: int64(err.Code), p: unsafe.Pointer(&msg), } } type SyntaxError struct { Pos int Src string Code types.ParsingError Msg string } func (self SyntaxError) Error() string { return fmt.Sprintf("%q", self.Description()) } func (self SyntaxError) Description() string { return "Syntax error " + self.description() } func (self SyntaxError) description() string { i := 16 p := self.Pos - i q := self.Pos + i /* check for empty source */ if self.Src == "" { return fmt.Sprintf("no sources available: %#v", self) } /* prevent slicing before the beginning */ if p < 0 { p, q, i = 0, q - p, i + p } /* prevent slicing beyond the end */ if n := len(self.Src); q > n { n = q - n q = len(self.Src) /* move the left bound if possible */ if p > n { i += n p -= n } } /* left and right length */ x := clamp_zero(i) y := clamp_zero(q - p - i - 1) /* compose the error description */ return fmt.Sprintf( "at index %d: %s\n\n\t%s\n\t%s^%s\n", self.Pos, self.Message(), self.Src[p:q], strings.Repeat(".", x), strings.Repeat(".", y), ) } func (self SyntaxError) Message() string { if self.Msg == "" { return self.Code.Message() } return self.Msg } func clamp_zero(v int) int { if v < 0 { return 0 } else { return v } }