Regular Expressions, Grammars & Parsing Flashcards
1
Q
Regular expressions
A
A sequence of characters that define a search pattern and a regular language
2
Q
|symbol meaning
symbol meaning
A
Boolean OR
3
Q
() symbol meaning
A
Grouping (equivalent to | symbol)
4
Q
. symbol meaning
A
Wild card- can match any one character
5
Q
[^a] symbol meaning
A
Negation
6
Q
gray|grey
A
gray or grey
7
Q
gr(a|e)y
A
gray|grey = gray or grey
8
Q
gr.y
A
gray, grey, groy, grzy etc..
9
Q
? symbol meaning
A
zero or one occurrences of the preceding element
10
Q
- symbol meaning
A
zero or more occurrences of the preceding element
11
Q
{n}
A
the preceding item is matched exactly n times
12
Q
{min, }
A
the preceding item is matched min or more times
13
Q
{min, max}
A
the preceding item is matched at least min times, but not more than max times
14
Q
colou?r
A
color, colour
15
Q
ab*c
A
ac, abc, abbc, abbbc etc..
