Fix default_value function when dealing with null token

This release comes with a fix regarding the null token used for kotlin applications.

default_value(null, "something") -> something

Add default_value() function

• Adds new function on the library.:

default_value(value, standard)

If the value is NULL, the result of this function is the standard, otherwise, the result is the value.

This function accept both integer, float, string and boolean types. (C++ overloading for the win)

Some success test samples: ✅

default_value(10, 1)
default_value(NULL, 1)
default_value(10.4, 1.01)
default_value(NULL, 1.01)
default_value("filled", "default")
default_value(NULL, "default")
default_value(false, true)
default_value(NULL, true)

Some failure test samples: 🚫

default_value(1, 4.5)
default_value(4.5, "string")
default_value("string", true)
default_value(true, 1)

Add add_days() and mask() functions

The new functions

mask(string, number)

mask(string, number)
# Result: The mask applied to a number

mask("000", 1) => "001"
mask("000", 1234) => "1234"
mask("000-000-000", 123456789) => "123-456-789"
mask("00/00/0000", 21011993) => "21/01/1993"

# Observation: You should not use a number that has more than 17 digits as a second parameter due to imprecision issues

add_days(date, number)

add_days(date, number)
# Result: The addition (in days) between a date and a days quantity.

add_days("2019-01-01", 3) => "2019-01-04"
add_days("2019-01-01T08:30", -1) => "2018-12-31T08:30"
add_days("2019-01-01T08:30", 0.5) => "2019-01-01T20:30"

Update current date

Update current date

Add diff hours

Add diff hours function.

Update native code

Update native code to add new methods.

Update gradle version

• Update gradle version to 4.6
• Remove unused packages
• Remove .idea folder

Fix error messages

• Add error message to date calculations.
• Catch runtime errors

Calculate formulas

• Add possibility to calculate formulas

Initial version

Added parsec c++ code
Added jni methods