Returns an instance of this class. Made private to follow the singleton pattern.
Answers if this position correspond to one in some SourceReader, or if it is unknown.
Returns the single instance of this class.
The column number of this position in the current input.
PRECONDITIONS:
INVARIANT: column >= 1 and it is a valid column in that reader.
SourceReader/Errors.InvalidOperationAtUnknownPositionError if the position is unknown.
SourceReader/Errors.InvalidOperationAtEOIError if the position is at the end of input.
The name of the input document this position belongs to.
PRECONDITIONS:
SourceReader/Errors.InvalidOperationAtUnknownPositionError if the position is unknown.
SourceReader/Errors.InvalidOperationAtEOIError if the position is at the end of input.
The contents of the input document this position belongs to (both visible and non visible).
PRECONDITIONS:
SourceReader/Errors.InvalidOperationAtUnknownPositionError if the receiver is unknown.
SourceReader/Errors.InvalidOperationAtEOIError if the receiver is the end of input.
Answers if this position corresponds to the end of a document in the SourceReader it belongs, or not. The EndOfDocument is reached when all the characters in a document in the source input has been processed, but before the processing of the next document started.
PRECONDITIONS:
SourceReader/Errors.InvalidOperationAtUnknownPositionError if the position is unknown.
SourceReader/Errors.InvalidOperationAtEOIError if the position is at the end of input.
Answers if this position corresponds to the end of input of the SourceReader it belongs, or not. The EndOfInput is reached when all documents in the source input has been processed.
PRECONDITIONS:
SourceReader/Errors.InvalidOperationAtUnknownPositionError if the position is unknown.
The line number of this position in the current input.
PRECONDITIONS:
INVARIANT: line >=1, and it is a valid line in that reader.
SourceReader/Errors.InvalidOperationAtUnknownPositionError if the position is unknown.
SourceReader/Errors.InvalidOperationAtEOIError if the position is at the end of input.
The regions the position in the current input belongs to.
PRECONDITIONS:
INVARIANT: the regions are valid in the position's reader.
SourceReader/Errors.InvalidOperationAtUnknownPositionError if the position is unknown.
SourceReader/Errors.InvalidOperationAtEOIError if the position is at the end of input.
The contents of the visible input document this position belongs to.
PRECONDITIONS:
SourceReader/Errors.InvalidOperationAtUnknownPositionError if the receiver is unknown.
SourceReader/Errors.InvalidOperationAtEOIError if the receiver is the end of input.
Returns the full context of the source document after the position, up to the beginning of the given number of lines or the end of the document.
The char at the given position is the first one in the solution.
PRECONDITIONS:
SourceReader/Errors.InvalidOperationAtUnknownPositionError if the position is unknown.
SourceReader/Errors.InvalidOperationAtEOIError if the position is at the end of input.
Returns the full context of the source document before the position, up to the beginning of the given number of lines, or the beginning of the document, whichever comes first.
The char at the given position is NOT included in the solution.
PRECONDITIONS:
SourceReader/Errors.InvalidOperationAtUnknownPositionError if the position is unknown.
SourceReader/Errors.InvalidOperationAtEOIError if the position is at the end of input.
The exact portion of the source that is enclosed between the argument position and the receiver position (not included), both visible and non visible. If the receiver does not come after the argument, the result is the empty string.
PRECONDITIONS:
A SourcePosition related with the same SourceReader that the receiver. It indicates a starting position to consult, where the receiver is the last.
SourceReader/Errors.InvalidOperationAtUnknownPositionError if the receiver or the argument positions are unknown.
SourceReader/Errors.MismatchedInputsError if the receiver and the argument positions do not belong to the same reader.
SourceReader/Errors.InvalidOperationAtEOIError if the receiver is the end of input.
The exact portion of the source, both visible and non visible, that is enclosed between the receiver position and the argument position (not included). If the argument does not come after the receiver, the result is the empty string.
PRECONDITIONS:
A SourcePosition related with the same SourceReader that the receiver. It indicates a final position to consult, where the receiver is the first.
SourceReader/Errors.InvalidOperationAtUnknownPositionError if the receiver or the argument positions are unknown.
SourceReader/Errors.MismatchedInputsError if the receiver and the argument positions do not belong to the same reader.
SourceReader/Errors.InvalidOperationAtEOIError if the receiver is the end of input.
The exact portion of the source that is enclosed between the from
position and this position (not included) and is visible. If this
does not come after from, the result is the empty string.
PRECONDITIONS:
A SourcePosition related with the same SourceReader that the receiver. It indicates a starting position to consult, where the receiver is the last.
SourceReader/Errors.InvalidOperationAtUnknownPositionError if the receiver or the argument positions are unknown.
SourceReader/Errors.MismatchedInputsError if the receiver and the argument positions do not belong to the same reader.
SourceReader/Errors.InvalidOperationAtEOIError if the receiver is the end of input.
The exact portion of the source that is enclosed between the this
position and to position (not included) and is visible. If to does
not come after this, the result is the empty string.
PRECONDITIONS:
A SourcePosition related with the same SourceReader that the receiver. It indicates a final position to consult, where the receiver is the first.
SourceReader/Errors.InvalidOperationAtUnknownPositionError if the receiver or the argument positions are unknown.
SourceReader/Errors.MismatchedInputsError if the receiver and the argument positions do not belong to the same reader.
SourceReader/Errors.InvalidOperationAtEOIError if the receiver is the end of input.
An UnknownSourcePosition represents an unknown source position, that is, it does not point to any position in any source reader. These positions responds with
trueto the operation isUnknown.It is used when a position must be provided, but no one is known, working as a Null Object Pattern. Additionally, this class follows the Singleton Pattern using an eager initialization.
This class has a single instance, accessible through the instance static field, and cannot be further instantiated.