Method syntaxErrorAt

syntax/parser.go:155–197

---------------------------------------------------------------------------- Error handling syntaxErrorAt reports a syntax error at the given position.

(pos Pos, msg string)

// syntaxErrorAt reports a syntax error at the given position.
func (p *parser) syntaxErrorAt(pos Pos, msg string) {
	if trace {
		p.print("syntax error: " + msg)
	}

	if p.tok == _EOF && p.first != nil {
		return // avoid meaningless follow-up errors
	}

	// add punctuation etc. as needed to msg
	switch {
	case msg == "":
		// nothing to do
	case strings.HasPrefix(msg, "in "), strings.HasPrefix(msg, "at "), strings.HasPrefix(msg, "after "):
		msg = " " + msg
	case strings.HasPrefix(msg, "expecting "):
		msg = ", " + msg
	default:
		// plain error - we don't care about current token
		p.errorAt(pos, "syntax error: "+msg)
		return
	}

	// determine token string
	var tok string
	switch p.tok {
	case _Name, _Semi:
		tok = p.lit
	case _Literal:
		tok = "literal " + p.lit
	case _Operator:
		tok = p.op.String()
	case _AssignOp:
		tok = p.op.String() + "="
	case _IncOp:
		tok = p.op.String()
		tok += tok
	default:
		tok = tokstring(p.tok)
	}

	p.errorAt(pos, "syntax error: unexpected "+tok+msg)
}

// tokstring returns the English word for selected punctuation tokens
// for more readable error messages. Use tokstring (not tok.String())