Question

Python uses indention in its program structures. How do you define the syntax of a language construct that uses indention? Give an example to describe.

Answer 1

Solution:

There are two parts to create language:
    1. Lexeme specification: defines groups of characters that represent a single syntactic construct like token or terminal value
    2. Grammar specification: defines the valid combinations of syntactic constructs/tokens/terminal values that make up non-terminal values that express how the language can be used in level

start ::= list
        | list NEWLINE
        .

list ::= entry
        | list entry
        .

entry ::= STRING NEWLINE
        | STRING NEWLINE INDENT list DEDENT
        .

Sample if-statement:
x = true
if x:
   print("x is true")
else:
   print("x is false")

There are two parts to create language: 1. Lexeme specification: defines groups of characters that represent a single syntactic construct like token or terminal value 2. Grammar specification: defines the valid combinations of syntactic constructs/tokens/terminal values that make up non-terminal, values that express how the language can be used start ::= list list NEWLINE list ::= entry | list entry entry ::= STRING NEWLINE STRING NEWLINE INDENT list DEDENT Simple program: x = true if x: print("x is true") else: print("x is false")