Пример #1
0
void Alg_midifile_reader::Mf_starttrack()
{
    // printf("starting new track\n");
    // create a new track that will share the sequence time map
    // since time is in beats, the seconds parameter is false
    track_number++;
    seq->add_track(track_number); // make sure track exists
    track = seq->track(track_number); // keep pointer to current track
    meta_channel = -1;
    port = 0;
}
Пример #2
0
bool Alg_reader::parse()
{
    int voice = 0;
    int key = 60;
    double loud = 100.0;
    double pitch = 60.0;
    double dur = 1.0;
    double time = 0.0;
    int track_num = 0;
    seq->convert_to_seconds();
    //seq->set_real_dur(0.0); // just in case it's not initialized already
    readline();
    bool valid = false; // ignore blank lines
    while (line_parser_flag) {
        bool time_flag = false;
        bool next_flag = false;
        double next;
        bool voice_flag = false;
        bool loud_flag = false;
        bool dur_flag = false;
        bool new_pitch_flag = false; // "P" syntax or "A"-"G" syntax
        double new_pitch = 0.0;
        bool new_key_flag = false;   // "K" syntax
        int new_key = 0;
        Alg_parameters_ptr attributes = NULL;
        if (line_parser.peek() == '#') {
            // look for #track
            line_parser.get_nonspace_quoted(field);
            if (streql(field.c_str(), "#track")) {
                line_parser.get_nonspace_quoted(field); // number
                field.insert(0, " "); // need char at beginning because
                // parse_int ignores the first character of the argument
                track_num = parse_int(field);
                seq->add_track(track_num);

                // maybe we have a sequence or track name
                line_parser.get_remainder(field);
                // if there is a non-space character after #track n then
                // use it as sequence or track name. Note that because we
                // skip over spaces, a sequence or track name cannot begin
                // with leading blanks. Another decision is that the name
                // must be at time zero
                if (field.length() > 0) {
                    // insert the field as sequence name or track name
                    Alg_update_ptr update = new Alg_update;
                    update->chan = -1;
                    update->time = 0;
                    update->set_identifier(-1);
                    // sequence name is whatever is on track 0
                    // other tracks have track names
                    const char *attr =
                            (track_num == 0 ? "seqnames" : "tracknames");
                    update->parameter.set_attr(
                            symbol_table.insert_string(attr));
                    update->parameter.s = heapify(field.c_str());
                    seq->add_event(update, track_num);
                }
            } else if (streql(field.c_str(), "#offset")) {
                if (offset_found) {
                    parse_error(field, 0, "#offset specified twice");
                }
                offset_found = true;
                line_parser.get_nonspace_quoted(field); // number
                field.insert(0, " "); // need char at beginning because
                // parse_real ignores first character in the argument
                offset = parse_real(field);
            }
        } else {
            // we must have a track to insert into
            if (seq->tracks() == 0) seq->add_track(0);
            line_parser.get_nonspace_quoted(field);
            char pk = line_parser.peek();
            // attributes are parsed as two adjacent nonspace_quoted tokens
            // so we have to conditionally call get_nonspace_quoted() again
            if (pk && !isspace(pk)) {
                string field2;
                line_parser.get_nonspace_quoted(field2);
                field.append(field2);
            }
            while (field[0]) {
                char first = toupper(field[0]);
                if (strchr("ABCDEFGKLPUSIQHW-", first)) {
                    valid = true; // it's a note or event
                }
                if (first == 'V') {
                    if (voice_flag) {
                        parse_error(field, 0, "Voice specified twice");
                    } else {
                        voice = parse_chan(field);
                    }
                    voice_flag = true;
                } else if (first == 'T') {
                    if (time_flag) {
                        parse_error(field, 0, "Time specified twice");
                    } else {
                        time = parse_dur(field, 0.0);
                    }
                    time_flag = true;
                } else if (first == 'N') {
                    if (next_flag) {
                        parse_error(field, 0, "Next specified twice");
                    } else {
                        next = parse_dur(field, time);
                    }
                    next_flag = true;
                } else if (first == 'K') {
                    if (new_key_flag) {
                        parse_error(field, 0, "Key specified twice");
                    } else {
                        new_key = parse_key(field);
                        new_key_flag = true;
                    }
                } else if (first == 'L') {
                    if (loud_flag) {
                        parse_error(field, 0, "Loudness specified twice");
                    } else {
                        loud = parse_loud(field);
                    }
                    loud_flag = true;
                } else if (first == 'P') {
                    if (new_pitch_flag) {
                        parse_error(field, 0, "Pitch specified twice");
                    } else {
                        new_pitch = parse_pitch(field);
                        new_pitch_flag = true;
                    }
                } else if (first == 'U') {
                    if (dur_flag) {
                        parse_error(field, 0, "Dur specified twice");
                    } else {
                        dur = parse_dur(field, time);
                        dur_flag = true;
                    }
                } else if (strchr("SIQHW", first)) {
                    if (dur_flag) {
                        parse_error(field, 0, "Dur specified twice");
                    } else {
                        // prepend 'U' to field, copy EOS too
                        field.insert((unsigned int) 0, 1, 'U');
                        dur = parse_dur(field, time);
                        dur_flag = true;
                    }
                } else if (strchr("ABCDEFG", first)) {
                    if (new_pitch_flag) {
                        parse_error(field, 0, "Pitch specified twice");
                    } else {
                        // prepend 'P' to field
                        field.insert((unsigned int) 0, 1, 'P');
                        new_pitch = parse_pitch(field);
                        new_pitch_flag = true;
                    }
                } else if (first == '-') {
                    Alg_parameter parm;
                    if (parse_attribute(field, &parm)) { // enter attribute-value pair
                        attributes = new Alg_parameters(attributes);
                        attributes->parm = parm;
                        parm.s = NULL; // protect string from deletion by destructor
                    }
                } else {
                    parse_error(field, 0, "Unknown field");
                }

                if (error_flag) {
                    field[0] = 0; // exit the loop
                } else {
                    line_parser.get_nonspace_quoted(field);
                    pk = line_parser.peek();
                    // attributes are parsed as two adjacent nonspace_quoted 
                    // tokens so we have to conditionally call 
                    // get_nonspace_quoted() again
                    if (pk && !isspace(pk)) {
                        string field2;
                        line_parser.get_nonspace_quoted(field2);
                        field.append(field2);
                    }
                }
            }
            // a case analysis:
            // Key < 128 implies pitch unless pitch is explicitly given
            // Pitch implies Key unless key is explicitly given,
            // Pitch is rounded to nearest integer to determine the Key
            //    if necessary, so MIDI files will lose the pitch fraction
            // A-G is a Pitch specification (therefore it implies Key)
            //   K60 P60 -- both are specified, use 'em
            //   K60 P60 C4 -- overconstrained, an error
            //   K60 C4 -- OK, but K60 is already implied by C4
            //   K60 -- OK, pitch is 60
            //   C4 P60 -- over constrained
            //   P60 -- OK, key is 60
            //   P60.1 -- OK, key is 60
            //   C4 -- OK, key is 60, pitch is 60
            //   <nothing> -- OK, key and pitch from before
            //   K200 P60 -- ok, pitch is 60
            //   K200 with neither P60 nor C4 uses 
            //       pitch from before

            // figure out what the key/instance is:
            if (new_key_flag) { // it was directly specified
                key = new_key;
            } else if (new_pitch_flag) {
                // pitch was specified, but key was not; get key from pitch
                key = (int) (new_pitch + 0.5); // round to integer key number
            }
            if (new_pitch_flag) {
                pitch = new_pitch;
            } else if (key < 128 && new_key_flag) {
                // no explicit pitch, but key < 128, so it implies pitch
                pitch = key;
                new_pitch_flag = true;
            }
            // now we've acquired new parameters
            // if (it is a note, then enter the note
            if (valid) {
                // change tempo or beat
                attributes = process_attributes(attributes, time);
                // if there's a duration or pitch, make a note:
                if (new_pitch_flag || dur_flag) {
                    Alg_note_ptr note_ptr = new Alg_note;
                    note_ptr->chan = voice;
                    note_ptr->time = time;
                    note_ptr->dur = dur;
                    note_ptr->set_identifier(key);
                    note_ptr->pitch = (float) pitch;
                    note_ptr->loud = (float) loud;
                    note_ptr->parameters = attributes;
                    seq->add_event(note_ptr, track_num); // sort later
                    if (seq->get_real_dur() < (time + dur)) seq->set_real_dur(time + dur);
                } else {
                    int update_key = -1;
                    // key must appear explicitly; otherwise
                    //    update applies to channel
                    if (new_key_flag) {
                        update_key = key;
                    }
                    if (loud_flag) {
                        Alg_update_ptr new_upd = new Alg_update;
                        new_upd->chan = voice;
                        new_upd->time = time;
                        new_upd->set_identifier(update_key);
                        new_upd->parameter.set_attr(symbol_table.insert_string("loudr"));
                        new_upd->parameter.r = pitch;
                        seq->add_event(new_upd, track_num);
                        if (seq->get_real_dur() < time) seq->set_real_dur(time);
                    }
                    if (attributes) {
                        while (attributes) {
                            Alg_update_ptr new_upd = new Alg_update;
                            new_upd->chan = voice;
                            new_upd->time = time;
                            new_upd->set_identifier(update_key);
                            new_upd->parameter = attributes->parm;
                            seq->add_event(new_upd, track_num);
                            Alg_parameters_ptr p = attributes;
                            attributes = attributes->next;
                            p->parm.s = NULL; // so we don't delete the string
                            delete p;
                        }
                    }
                }
                if (next_flag) {
                    time = time + next;
                } else if (dur_flag || new_pitch_flag) { // a note: incr by dur
                    time = time + dur;
                }
            }
        }
        readline();
    }
    if (!error_flag) { // why not convert even if there was an error? -RBD
        seq->convert_to_seconds(); // make sure format is correct
    }
    // real_dur is valid, translate to beat_dur
    seq->set_beat_dur((seq->get_time_map())->time_to_beat(seq->get_real_dur()));
    return error_flag;
}
Пример #3
0
#include "assert.h"
#include "stdlib.h"
#include "stdio.h"
#include "allegro.h"
#include "string.h"
#include "ctype.h"
//#include "memory.h"
#include "trace.h"
#include "strparse.h"
#ifndef EXPERIMENTAL_NOTE_TRACK
#include "allegrord.h"
#endif /* EXPERIMENTAL_NOTE_TRACK */
#define streql(s1, s2) (strcmp(s1, s2) == 0)
#define field_max 80


//Note that this is an #ifdef, not an #ifndef
#ifdef EXPERIMENTAL_NOTE_TRACK

class Alg_reader {
public:
    FILE *file;
    int line_no;
    String_parse line_parser;
    bool line_parser_flag;
    char field[field_max];
    bool error_flag;
    Alg_seq_ptr seq;
    double tsnum;
    double tsden;

    Alg_reader(FILE *a_file, Alg_seq_ptr new_seq);
    void readline();
    Alg_parameters_ptr process_attributes(Alg_parameters_ptr attributes, double time);
    bool parse();
    long parse_chan(char *field);
    long parse_int(char *field);
    int find_real_in(char *field, int n);
    double parse_real(char *field);
    void parse_error(char *field, long offset, char *message);
    double parse_dur(char *field, double base);
    double parse_after_dur(double dur, char *field, int n, double base);
    double parse_loud(char *field);
    long parse_key(char *field);
    double parse_pitch(char *field);
    long parse_after_key(int key, char *field, int n);
    long find_int_in(char *field, int n);
    bool parse_attribute(char *field, Alg_parameter_ptr parm);
    bool parse_val(Alg_parameter_ptr param, char *s, int i);
    bool check_type(char type_char, Alg_parameter_ptr param);
};

#endif /* EXPERIMENTAL_NOTE_TRACK */

void subseq(char *result, char *source, int from, int to)
{
    memcpy(result, source + from, to - from);
    result[to - from] = 0;
}

#ifndef EXPERIMENTAL_NOTE_TRACK
double Allegro_reader::parse_pitch(char *field)
#else /* EXPERIMENTAL_NOTE_TRACK */
double Alg_reader::parse_pitch(char *field)
#endif /* EXPERIMENTAL_NOTE_TRACK */
{
    if (isdigit(field[1])) {
        char real_string[80];
        int last = find_real_in(field, 1);
        subseq(real_string, field, 1, last);
        return atof(real_string);
    } else {
        return (double) parse_key(field);
    }
}


#ifndef EXPERIMENTAL_NOTE_TRACK
Allegro_reader::Allegro_reader(FILE *a_file)
{
    file = a_file; // save the file
    line_parser_flag = false;
    line_no = 0;
    seq = Seq();
    tsnum = 4; // default time signature
    tsden = 4;
}
#else /* EXPERIMENTAL_NOTE_TRACK */
// it is the responsibility of the caller to delete
// the seq
Alg_reader::Alg_reader(FILE *a_file, Alg_seq_ptr new_seq)
{
    file = a_file; // save the file
    line_parser_flag = false;
    line_no = 0;
    tsnum = 4; // default time signature
    tsden = 4;
    seq = new_seq;
}
#endif /* EXPERIMENTAL_NOTE_TRACK */


//Note that this is an #ifdef, not an #ifndef
#ifdef EXPERIMENTAL_NOTE_TRACK
Alg_seq_ptr alg_read(FILE *file, Alg_seq_ptr new_seq)
    // read a sequence from allegro file
{
    if (!new_seq) new_seq = new Alg_seq();
    Alg_reader alg_reader(file, new_seq);
    alg_reader.parse();
    return alg_reader.seq;
}
#endif /* EXPERIMENTAL_NOTE_TRACK */


#ifndef EXPERIMENTAL_NOTE_TRACK
void Allegro_reader::readline()
#else /* EXPERIMENTAL_NOTE_TRACK */
void Alg_reader::readline()
#endif /* EXPERIMENTAL_NOTE_TRACK */
{
    char line[256];
    char *line_flag = fgets(line, 256, file);
    line_parser_flag = false;
    if (line_flag) {
        line_parser.init(line);
        line_parser_flag = true;
        error_flag = false;
    }
}


#ifndef EXPERIMENTAL_NOTE_TRACK
void Allegro_reader::process_attributes(Parameters_ptr attributes, double time)
{
    // print "process_attributes:", attributes
    bool ts_flag;
    if (attributes) {
        Parameters_ptr a;
        if (a = Parameters::remove_key(&attributes, "tempor")) {
            double tempo = a->parm.r;
            seq.insert_tempo(tempo, seq.map.time_to_beat(time));
        }
        if (a = Parameters::remove_key(&attributes, "beatr")) {
            double beat = a->parm.r;
            seq.insert_beat(time, beat);
        }
        if (a = Parameters::remove_key(&attributes, "tsnumr")) {
            tsnum = a->parm.r;
            ts_flag = true;
        }
        if (a = Parameters::remove_key(&attributes, "tsdenr")) {
            tsden = a->parm.r;
            ts_flag = true;
        }
        if (ts_flag) {
            seq.set_time_sig(seq.map.time_to_beat(time), tsnum, tsden);
        }
    }
}
#else /* EXPERIMENTAL_NOTE_TRACK */
Alg_parameters_ptr Alg_reader::process_attributes(
        Alg_parameters_ptr attributes, double time)
{
    // print "process_attributes:", attributes
    bool ts_flag = false;
    if (attributes) {
        Alg_parameters_ptr a;
        bool in_seconds = seq->get_units_are_seconds();
        if (a = Alg_parameters::remove_key(&attributes, "tempor")) {
            double tempo = a->parm.r;
            seq->insert_tempo(tempo, seq->get_time_map()->time_to_beat(time));
        }
        if (a = Alg_parameters::remove_key(&attributes, "beatr")) {
            double beat = a->parm.r;
            seq->insert_beat(time, beat);
        }
        if (a = Alg_parameters::remove_key(&attributes, "timesig_numr")) {
            tsnum = a->parm.r;
            ts_flag = true;
        }
        if (a = Alg_parameters::remove_key(&attributes, "timesig_denr")) {
            tsden = a->parm.r;
            ts_flag = true;
        }
        if (ts_flag) {
            seq->set_time_sig(seq->get_time_map()->time_to_beat(time),
            tsnum, tsden);
        }
        if (in_seconds) seq->convert_to_seconds();
    }
    return attributes; // in case it was modified
}
#endif /* EXPERIMENTAL_NOTE_TRACK */

#ifndef EXPERIMENTAL_NOTE_TRACK
bool Allegro_reader::parse()
{
    int voice = 0;
    int key = 60;
    double loud = 100.0;
    double pitch = 60.0;
    double dur = 1.0;
    double time = 0.0;
    readline();
    bool valid = false; // ignore blank lines
    while (line_parser_flag) {
        bool time_flag = false;
        bool next_flag = false;
        double next;
        bool voice_flag = false;
        bool loud_flag = false;
        bool dur_flag = false;
        bool new_pitch_flag = false; // "P" syntax
        double new_pitch = 0.0;
        bool new_key_flag = false;   // "K" syntax
        int new_key = 0;
        bool new_note_flag = false;  // "A"-"G" syntax
        int new_note = 0;
        Parameters_ptr attributes = NULL;
        line_parser.get_nonspace_quoted(field);
        char pk = line_parser.peek();
        if (pk && !isspace(pk)) {
            line_parser.get_nonspace_quoted(field + strlen(field));
        }
        while (field[0]) {
            // print "field", "|";field;"|", "|";line_parser.string;"|", line_parser.pos
            char first = toupper(field[0]);
            if (strchr("ABCDEFGKLPUSIQHW-", first)) {
                valid = true; // it's a note or event
            }
            if (first == 'V') {
                if (voice_flag) {
                    parse_error(field, 0, "Voice specified twice");
                } else {
                    voice = parse_int(field);
                }
                voice_flag = true;
            } else if (first == 'T') {
                if (time_flag) {
                    parse_error(field, 0, "Time specified twice");
                } else {
                    time = parse_dur(field, 0.0);
                }
                time_flag = true;
            } else if (first == 'N') {
                if (next_flag) {
                    parse_error(field, 0, "Next specified twice");
                } else {
                    next = parse_dur(field, time);
                }
                next_flag = true;
            } else if (first == 'K') {
                if (new_key_flag) {
                    parse_error(field, 0, "Key specified twice");
                } else {
                    new_key = parse_key(field);
                    new_key_flag = true;
                }
            } else if (first == 'L') {
                if (loud_flag) {
                    parse_error(field, 0, "Loudness specified twice");
                } else {
                    loud = parse_loud(field);
                }
                loud_flag = true;
            } else if (first == 'P') {
                if (new_note_flag || new_pitch_flag) {
                    parse_error(field, 0, "Pitch specified twice");
                } else {
                    new_pitch = parse_pitch(field);
                    new_pitch_flag = true;
                }
            } else if (first == 'U') {
                if (dur_flag) {
                    parse_error(field, 0, "Dur specified twice");
                } else {
                    dur = parse_dur(field, time);
                    dur_flag = true;
                }
            } else if (strchr("SIQHW", first)) {
                if (dur_flag) {
                    parse_error(field, 0, "Dur specified twice");
                } else {
                    // prepend 'U' to field, copy EOS too
                    memmove(field + 1, field, strlen(field) + 1);
                    field[0] = 'U';
                    dur = parse_dur(field, time);
                    dur_flag = true;
                }
            } else if (strchr("ABCDEFG", first)) {
                if (new_note_flag || new_pitch_flag) {
                    parse_error(field, 0, "Pitch specified twice");
                } else {
                    // prepend 'K' to field, copy EOS too
                    memmove(field + 1, field, strlen(field) + 1);
                    field[0] = 'K';
                    new_note = parse_key(field);
                    new_note_flag = true;
                }
            } else if (first == '-') {
                Parameter parm;
                if (parse_attribute(field, &parm)) { // enter attribute-value pair
                    attributes = new Parameters(attributes);
                    attributes->parm = parm;
                    parm.s = NULL; // protect string from deletion by destructor
                }
            } else {
                parse_error(field, 0, "Unknown field");
            }

            if (error_flag) {
                field[0] = 0; // exit the loop
            } else {
                line_parser.get_nonspace_quoted(field);
                pk = line_parser.peek();
                if (pk && !isspace(pk)) {
                    line_parser.get_nonspace_quoted(field + strlen(field));
                }
            }
        }
        // a case analysis:
        // Key < 128 counts as both key and pitch
        // A-G implies pitch AND key unless key given too
        //   K60 P60 -- both are specified, use 'em
        //   K60 P60 C4 -- overconstrained, an error
        //   K60 C4 -- overconstrained
        //   K60 -- OK, pitch is 60
        //   C4 P60 -- over constrained
        //   P60 -- OK, key is from before, pitch is 60
        //   C4 -- OK, key is 60, pitch is 60
        //   <nothing> -- OK, key and pitch from before
        //   K200 with P60 ok, pitch is 60
        //   K200 with neither P60 nor C4 uses 
        //       pitch from before
        // figure out what the key/instance is:
        if (new_key_flag) { // it was directly specified
            key = new_key;
            if (key < 128 && new_note_flag) {
                parse_error("", 0, "Pitch specified twice");
            }
        } else if (new_note_flag) { // "A"-"G" used
            key = new_note;
        }
        if (new_pitch_flag) {
            pitch = new_pitch;
        } else if (key < 128) {
            pitch = key;
        }
        // now we've acquired new parameters
        // if (it is a note, then enter the note
        if (valid) {
            // change tempo or beat
            process_attributes(attributes, time);
            // if there's a duration or pitch, make a note:
            if (new_pitch_flag || dur_flag || new_note_flag) {
                new_key_flag = false;
                new_pitch_flag = false;
                Allegro_note_ptr note_ptr = new Allegro_note;
                note_ptr->chan = voice;
                note_ptr->time = time;
                note_ptr->dur = dur;
                note_ptr->key = key;
                note_ptr->pitch = pitch;
                note_ptr->loud = loud;
                note_ptr->parameters = attributes;
                seq.add_event(note_ptr); // sort later
            } else {
                int update_key = -1;
                // key or pitch must appear explicitly; otherwise
                //    update applies to channel
                if (new_key_flag || new_pitch_flag) {
                    update_key = key;
                }
                if (loud_flag) {
                    Allegro_update_ptr new_upd = new Allegro_update;
                    new_upd->chan = voice;
                    new_upd->time = time;
                    new_upd->key = update_key;
                    new_upd->parameter.set_attr(symbol_table.insert_string("loudr"));
                    new_upd->parameter.r = pitch;
                    seq.add_event(new_upd);
                }
                if (attributes) {
                    while (attributes) {
                        Allegro_update_ptr new_upd = new Allegro_update;
                        new_upd->chan = voice;
                        new_upd->time = time;
                        new_upd->key = update_key;
                        new_upd->parameter = attributes->parm;
                        seq.add_event(new_upd);
                        Parameters_ptr p = attributes;
                        attributes = attributes->next;
                        delete p;
                    }
                }
            }
            if (next_flag) {
                time = time + next;
            } else if (dur_flag) {
                time = time + dur;
            }
        }
        readline();
    }
    //print "Finished reading score"
    if (!error_flag) {
        seq.convert_to_seconds(); // make sure format is correct
        // seq.notes.sort('event_greater_than');
    }
    // print "parse returns error_flag", error_flag
    return error_flag;
}
#else /* EXPERIMENTAL_NOTE_TRACK */
bool Alg_reader::parse()
{
    int voice = 0;
    int key = 60;
    double loud = 100.0;
    double pitch = 60.0;
    double dur = 1.0;
    double time = 0.0;
    int track_num = 0;
    seq->convert_to_seconds();
    //seq->set_real_dur(0.0); // just in case it's not initialized already
    readline();
    bool valid = false; // ignore blank lines
    while (line_parser_flag) {
        bool time_flag = false;
        bool next_flag = false;
        double next;
        bool voice_flag = false;
        bool loud_flag = false;
        bool dur_flag = false;
        bool new_pitch_flag = false; // "P" syntax
        double new_pitch = 0.0;
        bool new_key_flag = false;   // "K" syntax
        int new_key = 0;
        bool new_note_flag = false;  // "A"-"G" syntax
        int new_note = 0;
        Alg_parameters_ptr attributes = NULL;
        if (line_parser.peek() == '#') {
            // look for #track
            line_parser.get_nonspace_quoted(field);
            if (streql(field, "#track")) {
                line_parser.get_nonspace_quoted(field); // number
                track_num = parse_int(field - 1);
                seq->add_track(track_num);
            }
            // maybe we have a comment
        } else {
            // we must have a track to insert into
            if (seq->tracks() == 0) seq->add_track(0);
            line_parser.get_nonspace_quoted(field);
            char pk = line_parser.peek();
            // attributes are parsed as two adjacent nonspace_quoted tokens
            // so we have to conditionally call get_nonspace_quoted() again
            if (pk && !isspace(pk)) {
                line_parser.get_nonspace_quoted(field + strlen(field));
            }
            while (field[0]) {
                char first = toupper(field[0]);
                if (strchr("ABCDEFGKLPUSIQHW-", first)) {
                    valid = true; // it's a note or event
                }
                if (first == 'V') {
                    if (voice_flag) {
                        parse_error(field, 0, "Voice specified twice");
                    } else {
                        voice = parse_chan(field);
                    }
                    voice_flag = true;
                } else if (first == 'T') {
                    if (time_flag) {
                        parse_error(field, 0, "Time specified twice");
                    } else {
                        time = parse_dur(field, 0.0);
                    }
                    time_flag = true;
                } else if (first == 'N') {
                    if (next_flag) {
                        parse_error(field, 0, "Next specified twice");
                    } else {
                        next = parse_dur(field, time);
                    }
                    next_flag = true;
                } else if (first == 'K') {
                    if (new_key_flag) {
                        parse_error(field, 0, "Key specified twice");
                    } else {
                        new_key = parse_key(field);
                        new_key_flag = true;
                    }
                } else if (first == 'L') {
                    if (loud_flag) {
                        parse_error(field, 0, "Loudness specified twice");
                    } else {
                        loud = parse_loud(field);
                    }
                    loud_flag = true;
                } else if (first == 'P') {
                    if (new_note_flag || new_pitch_flag) {
                        parse_error(field, 0, "Pitch specified twice");
                    } else {
                        new_pitch = parse_pitch(field);
                        new_pitch_flag = true;
                    }
                } else if (first == 'U') {
                    if (dur_flag) {
                        parse_error(field, 0, "Dur specified twice");
                    } else {
                        dur = parse_dur(field, time);
                        dur_flag = true;
                    }
                } else if (strchr("SIQHW", first)) {
                    if (dur_flag) {
                        parse_error(field, 0, "Dur specified twice");
                    } else {
                        // prepend 'U' to field, copy EOS too
                        memmove(field + 1, field, strlen(field) + 1);
                        field[0] = 'U';
                        dur = parse_dur(field, time);
                        dur_flag = true;
                    }
                } else if (strchr("ABCDEFG", first)) {
                    if (new_note_flag || new_pitch_flag) {
                        parse_error(field, 0, "Pitch specified twice");
                    } else {
                        // prepend 'K' to field, copy EOS too
                        memmove(field + 1, field, strlen(field) + 1);
                        field[0] = 'K';
                        new_note = parse_key(field);
                        new_note_flag = true;
                    }
                } else if (first == '-') {
                    Alg_parameter parm;
                    if (parse_attribute(field, &parm)) { // enter attribute-value pair
                        attributes = new Alg_parameters(attributes);
                        attributes->parm = parm;
                        parm.s = NULL; // protect string from deletion by destructor
                    }
                } else {
                    parse_error(field, 0, "Unknown field");
                }

                if (error_flag) {
                    field[0] = 0; // exit the loop
                } else {
                    line_parser.get_nonspace_quoted(field);
                    pk = line_parser.peek();
                    // attributes are parsed as two adjacent nonspace_quoted 
                    // tokens so we have to conditionally call 
                    // get_nonspace_quoted() again
                    if (pk && !isspace(pk)) {
                        line_parser.get_nonspace_quoted(field + strlen(field));
                    }
                }
            }
            // a case analysis:
            // Key < 128 counts as both key and pitch
            // A-G implies pitch AND key unless key given too
            //   K60 P60 -- both are specified, use 'em
            //   K60 P60 C4 -- overconstrained, an error
            //   K60 C4 -- overconstrained
            //   K60 -- OK, pitch is 60
            //   C4 P60 -- over constrained
            //   P60 -- OK, key is from before, pitch is 60
            //   C4 -- OK, key is 60, pitch is 60
            //   <nothing> -- OK, key and pitch from before
            //   K200 with P60 ok, pitch is 60
            //   K200 with neither P60 nor C4 uses 
            //       pitch from before
            // figure out what the key/instance is:
            if (new_key_flag) { // it was directly specified
                key = new_key;
                if (key < 128 && new_note_flag) {
                    parse_error("", 0, "Pitch specified twice");
                }
            } else if (new_note_flag) { // "A"-"G" used
                key = new_note;
            }
            if (new_pitch_flag) {
                pitch = new_pitch;
            } else if (key < 128) {
                pitch = key;
            }
            // now we've acquired new parameters
            // if (it is a note, then enter the note
            if (valid) {
                // change tempo or beat
                attributes = process_attributes(attributes, time);
                // if there's a duration or pitch, make a note:
                if (new_pitch_flag || dur_flag || new_note_flag) {
                    new_key_flag = false;
                    new_pitch_flag = false;
                    Alg_note_ptr note_ptr = new Alg_note;
                    note_ptr->chan = voice;
                    note_ptr->time = time;
                    note_ptr->dur = dur;
                    note_ptr->set_identifier(key);
                    note_ptr->pitch = pitch;
                    note_ptr->loud = loud;
                    note_ptr->parameters = attributes;
                    seq->add_event(note_ptr, track_num); // sort later
                    if (seq->get_real_dur() < (time + dur)) seq->set_real_dur(time + dur);
                } else {
                    int update_key = -1;
                    // key or pitch must appear explicitly; otherwise
                    //    update applies to channel
                    if (new_key_flag || new_pitch_flag) {
                        update_key = key;
                    }
                    if (loud_flag) {
                        Alg_update_ptr new_upd = new Alg_update;
                        new_upd->chan = voice;
                        new_upd->time = time;
                        new_upd->set_identifier(update_key);
                        new_upd->parameter.set_attr(symbol_table.insert_string("loudr"));
                        new_upd->parameter.r = pitch;
                        seq->add_event(new_upd, track_num);
                        if (seq->get_real_dur() < time) seq->set_real_dur(time);
                    }
                    if (attributes) {
                        while (attributes) {
                            Alg_update_ptr new_upd = new Alg_update;
                            new_upd->chan = voice;
                            new_upd->time = time;
                            new_upd->set_identifier(update_key);
                            new_upd->parameter = attributes->parm;
                            seq->add_event(new_upd, track_num);
                            Alg_parameters_ptr p = attributes;
                            attributes = attributes->next;
                            p->parm.s = NULL; // so we don't delete the string
                            delete p;
                        }
                    }
                }
                if (next_flag) {
                    time = time + next;
                } else if (dur_flag) {
                    time = time + dur;
                }
            }
        }
        readline();
    }
    //print "Finished reading score"
    if (!error_flag) {
        seq->convert_to_seconds(); // make sure format is correct
        // seq->notes.sort('event_greater_than');
    }
    // real_dur is valid, translate to beat_dur
    seq->set_beat_dur((seq->get_time_map())->time_to_beat(seq->get_real_dur()));
    // print "parse returns error_flag", error_flag
    return error_flag;
}