CREATE FUNCTION flow_in(cstring)
RETURNS flow
AS 'MODULE_PATHNAME'
LANGUAGE C IMMUTABLE STRICT;

CREATE FUNCTION flow_out(flow)
RETURNS cstring
AS 'MODULE_PATHNAME'
LANGUAGE C IMMUTABLE STRICT;

CREATE FUNCTION flow_status(flow)
RETURNS cstring
AS 'MODULE_PATHNAME'
LANGUAGE C IMMUTABLE STRICT;

CREATE FUNCTION flow_omega(flow)
RETURNS float8
AS 'MODULE_PATHNAME'
LANGUAGE C IMMUTABLE STRICT;

CREATE FUNCTION flow_omegax(flow,int8,int8)
RETURNS float8
AS 'MODULE_PATHNAME'
LANGUAGE C IMMUTABLE STRICT;

CREATE FUNCTION flow_proj(flow,int)
RETURNS int8[]
AS 'MODULE_PATHNAME'
LANGUAGE C IMMUTABLE STRICT;

CREATE FUNCTION flow_provides(flow)
RETURNS int8
AS 'MODULE_PATHNAME'
LANGUAGE C IMMUTABLE STRICT;

CREATE FUNCTION flow_get_fim1_fi(flow,int)
RETURNS int8[]
AS 'MODULE_PATHNAME'
LANGUAGE C IMMUTABLE STRICT;

CREATE FUNCTION flow_dim(flow)
RETURNS int4
AS 'MODULE_PATHNAME'
LANGUAGE C IMMUTABLE STRICT;

CREATE TYPE flow (
	INTERNALLENGTH = variable,
	INPUT = flow_in,
	OUTPUT = flow_out,
	ALIGNMENT = double
);

COMMENT ON TYPE flow IS 'flow ''[(id,nr,qtt_prov,qtt_requ,sid,own,qtt,np), ...]''';

-- (flow,id,nr,qtt_prov,qtt_requ,sid,own,qtt,np)
CREATE FUNCTION flow_cat(flow,int8,int8,int8,int8,int8,int8,int8,int8)
RETURNS flow
AS 'MODULE_PATHNAME'
LANGUAGE C IMMUTABLE STRICT;

CREATE FUNCTION flow_to_matrix(flow)
RETURNS int8[]
AS 'MODULE_PATHNAME'
LANGUAGE C IMMUTABLE STRICT;