fn transition_nfa()

in rust-csv/csv-core/src/reader.rs [985:1068]

• 84 lines of code
• 22 McCabe index (conditional complexity)

    fn transition_nfa(
        &self,
        state: NfaState,
        c: u8,
    ) -> (NfaState, NfaInputAction) {
        use self::NfaState::*;
        match state {
            End => (End, NfaInputAction::Epsilon),
            StartRecord => {
                if self.term.equals(c) {
                    (StartRecord, NfaInputAction::Discard)
                } else if self.comment == Some(c) {
                    (InComment, NfaInputAction::Discard)
                } else {
                    (StartField, NfaInputAction::Epsilon)
                }
            }
            EndRecord => (StartRecord, NfaInputAction::Epsilon),
            StartField => {
                if self.quoting && self.quote == c {
                    (InQuotedField, NfaInputAction::Discard)
                } else if self.delimiter == c {
                    (EndFieldDelim, NfaInputAction::Discard)
                } else if self.term.equals(c) {
                    (EndFieldTerm, NfaInputAction::Epsilon)
                } else {
                    (InField, NfaInputAction::CopyToOutput)
                }
            }
            EndFieldDelim => (StartField, NfaInputAction::Epsilon),
            EndFieldTerm => (InRecordTerm, NfaInputAction::Epsilon),
            InField => {
                if self.delimiter == c {
                    (EndFieldDelim, NfaInputAction::Discard)
                } else if self.term.equals(c) {
                    (EndFieldTerm, NfaInputAction::Epsilon)
                } else {
                    (InField, NfaInputAction::CopyToOutput)
                }
            }
            InQuotedField => {
                if self.quoting && self.quote == c {
                    (InDoubleEscapedQuote, NfaInputAction::Discard)
                } else if self.quoting && self.escape == Some(c) {
                    (InEscapedQuote, NfaInputAction::Discard)
                } else {
                    (InQuotedField, NfaInputAction::CopyToOutput)
                }
            }
            InEscapedQuote => (InQuotedField, NfaInputAction::CopyToOutput),
            InDoubleEscapedQuote => {
                if self.quoting && self.double_quote && self.quote == c {
                    (InQuotedField, NfaInputAction::CopyToOutput)
                } else if self.delimiter == c {
                    (EndFieldDelim, NfaInputAction::Discard)
                } else if self.term.equals(c) {
                    (EndFieldTerm, NfaInputAction::Epsilon)
                } else {
                    (InField, NfaInputAction::CopyToOutput)
                }
            }
            InComment => {
                if b'\n' == c {
                    (StartRecord, NfaInputAction::Discard)
                } else {
                    (InComment, NfaInputAction::Discard)
                }
            }
            InRecordTerm => {
                if self.term.is_crlf() && b'\r' == c {
                    (CRLF, NfaInputAction::Discard)
                } else {
                    (EndRecord, NfaInputAction::Discard)
                }
            }
            CRLF => {
                if b'\n' == c {
                    (StartRecord, NfaInputAction::Discard)
                } else {
                    (StartRecord, NfaInputAction::Epsilon)
                }
            }
        }
    }