Notes.md

pattern: (a*a)|c

Let's trace the execution:

Alternation(alternatives=[ Group(regex=Concatenation( items=[ Quantifier(atom=Character(value='a'), min_count=0, max_count=None, greedy=True), Character(value='b')] ), name=None, capturing=True), Character(value='c')])

This is the AST for the pattern.

Input String: aaa

How would the pattern match this string?

• In matcher.match() method, we will ask the generate match_node to yield its values by iterating over the loop.

• In match_node method, we will first call match_alternation and yield to match method: yield from self.match_alternation(node, pos)

  • By saying yield from, we are saying that for each value yielded from the match_alternation method, return that value to match().

• In match_alternation method, we iterate over each alternatives and then call match_node on that alternative & yield it. Here, the first alternative is the Group. In the Group, we again yield a value.