-/*
- * EMBL Feature support is limited. The text below is included for the benefit of
- * any developer working on improving EMBL feature import in Jalview.
- * Extract from EMBL feature specification
- * see http://www.embl-ebi.ac.uk/embl/Documentation/FT_definitions/feature_table.html
-3.5 Location
-3.5.1 Purpose
-
-The location indicates the region of the presented sequence which corresponds
-to a feature.
-
-3.5.2 Format and conventions
-The location contains at least one sequence location descriptor and may
-contain one or more operators with one or more sequence location descriptors.
-Base numbers refer to the numbering in the entry. This numbering designates
-the first base (5' end) of the presented sequence as base 1.
-Base locations beyond the range of the presented sequence may not be used in
-location descriptors, the only exception being location in a remote entry (see
-3.5.2.1, e).
-
-Location operators and descriptors are discussed in more detail below.
-
-3.5.2.1 Location descriptors
-
-The location descriptor can be one of the following:
-(a) a single base number
-(b) a site between two indicated adjoining bases
-(c) a single base chosen from within a specified range of bases (not allowed for new
- entries)
-(d) the base numbers delimiting a sequence span
-(e) a remote entry identifier followed by a local location descriptor
- (i.e., a-d)
-
-A site between two adjoining nucleotides, such as endonucleolytic cleavage
-site, is indicated by listing the two points separated by a carat (^). The
-permitted formats for this descriptor are n^n+1 (for example 55^56), or, for
-circular molecules, n^1, where "n" is the full length of the molecule, ie
-1000^1 for circular molecule with length 1000.
-
-A single base chosen from a range of bases is indicated by the first base
-number and the last base number of the range separated by a single period
-(e.g., '12.21' indicates a single base taken from between the indicated
-points). From October 2006 the usage of this descriptor is restricted :
-it is illegal to use "a single base from a range" (c) either on its own or
-in combination with the "sequence span" (d) descriptor for newly created entries.
-The existing entries where such descriptors exist are going to be retrofitted.
-
-Sequence spans are indicated by the starting base number and the ending base
-number separated by two periods (e.g., '34..456'). The '<' and '>' symbols may
-be used with the starting and ending base numbers to indicate that an end
-point is beyond the specified base number. The starting and ending base
-positions can be represented as distinct base numbers ('34..456') or a site
-between two indicated adjoining bases.
-
-A location in a remote entry (not the entry to which the feature table
-belongs) can be specified by giving the accession-number and sequence version
-of the remote entry, followed by a colon ":", followed by a location
-descriptor which applies to that entry's sequence (i.e. J12345.1:1..15, see
-also examples below)
-
-3.5.2.2 Operators
-
-The location operator is a prefix that specifies what must be done to the
-indicated sequence to find or construct the location corresponding to the
-feature. A list of operators is given below with their definitions and most
-common format.
-
-complement(location)
-Find the complement of the presented sequence in the span specified by "
-location" (i.e., read the complement of the presented strand in its 5'-to-3'
-direction)
-
-join(location,location, ... location)
-The indicated elements should be joined (placed end-to-end) to form one
-contiguous sequence
-
-order(location,location, ... location)
-The elements can be found in the
-specified order (5' to 3' direction), but nothing is implied about the
-reasonableness about joining them
-
-Note : location operator "complement" can be used in combination with either "
-join" or "order" within the same location; combinations of "join" and "order"
-within the same location (nested operators) are illegal.
-
-
-
-3.5.3 Location examples
-
-The following is a list of common location descriptors with their meanings:
-
-Location Description
-
-467 Points to a single base in the presented sequence
-
-340..565 Points to a continuous range of bases bounded by and
- including the starting and ending bases
-
-<345..500 Indicates that the exact lower boundary point of a feature
- is unknown. The location begins at some base previous to
- the first base specified (which need not be contained in
- the presented sequence) and continues to and includes the
- ending base
-
-<1..888 The feature starts before the first sequenced base and
- continues to and includes base 888
-
-1..>888 The feature starts at the first sequenced base and
- continues beyond base 888
-
-102.110 Indicates that the exact location is unknown but that it is
- one of the bases between bases 102 and 110, inclusive
-
-123^124 Points to a site between bases 123 and 124
-
-join(12..78,134..202) Regions 12 to 78 and 134 to 202 should be joined to form
- one contiguous sequence
-
-
-complement(34..126) Start at the base complementary to 126 and finish at the
- base complementary to base 34 (the feature is on the strand
- complementary to the presented strand)