[SYSTEMDS-296] Add elif (else if) to PyDML

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Component/s: Parser, PythonAPI
• Epic Link: Improve PyDML Language
• Assignee: Tatsuya Nishiyama
• Reporter: Jon Deron Eriksson
• Created: 09/Sep/15 23:45
• Updated: 02/Dec/23 19:05
• Resolved: 17/May/16 18:48

Description

"Else if" (elif) statements are useful since they avoid the need for nested if/else statements. Currently, DML has "else if" but PyDML does not have an equivalent "elif".

As an example, here is DML containing "else if" statements:

x = 6
if (x == 1) {
	print('A')
} else if (x == 2) {
	print('B')
} else if (x == 3) {
	print('C')
} else if (x == 4) {
	print('D')
} else if (x == 5) {
	print('E')
} else {
	print('F')
}

Here is the logical equivalent in PyDML using nested "if else" statements:

x = 6
if (x == 1):
    print('A')
else:
    if (x == 2):
        print('B')
    else:
        if (x == 3):
            print('C')
        else:
            if (x == 4):
                print('D')
            else:
                if (x == 5):
                    print('E')
                else:
                    print('F')

The nesting becomes especially challenging in a Python-like language as the number of nested "if else" statements increases due to the use of whitespace indentations to specify blocks of code.