This is a file that lets you read in variables from simple parameter files. An example parater file is:
# Example Parameter file
#--------------------------------------------------------------------
# Any line starting with a `#` is a comment.
# A comment goes until the end of the line
# The comment doesn't have to start at the first character.
#--------------------------------------------------------------------
# The main purpose is to list variables and values
var length 10.0
# The format is the keyword `var` followed by a variable name and a
# value. The variable name must have no spaces or whitespace, and the
# same with the values.
# The values be anything type
var width 10.0 # floating point values
var num_of_particles 100 # integers
var output_file_name output.dat # string
#--------------------------------------------------------------------# We can also give list of variables
list box_size 10.0 10.0
# The format is the keyword `list` followed by a variable name,
# followed by the list of values.
# Line breaks and other whitespace is not meaningfull
list tempuratures
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10