object LineMap

instance:
  line undefined
  columns empty

Instantiate task given pLine
  set line to pLine
  
Add task given column, source, options
  if options.noReplace and columns\column
    return
  set columns\column:
    line line
    column column
    sourceLine source.0
    sourceColumn source.1
    
SourceLocation task given column
  while column>=0 
    exists columns\column
      return: .sourceLine, .sourceColumn
    dec column
  return undefined