Fetches source information for the given clause. File is the
file from which the clause was loaded. TermPos describes the
source layout in a format compatible to the subterm_positions
option of read_term/2. VarOffsets provides access to the
variable allocation in a stack-frame. See make_varnames/5 for
details.
Note that positions are character positions, i.e., not
bytes. Line endings count as a single character, regardless of
whether the actual ending is \n or =|\r\n|_.
Defined options are:
- variable_names(-Names)
- Unify Names with the variable names list (Name=Var) as
returned by read_term/3. This argument is intended for
reporting source locations and refactoring based on
analysis of the compiled code.