tvl-depot/users/wpcarro/scratch/simple-select/parser.py
William Carroll eb412699b6 feat(wpcarro/simple-select): Parse query language 🎉
Seems to successfully handle inputs like...

```
> (-fname:"William" lname:/C.*l/) OR (fname:"William" -lname:"Carroll")
```

Change-Id: I5277cfbc7d102158eab5e1e71b2d95aaf13508fd
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5340
Reviewed-by: wpcarro <wpcarro@gmail.com>
Autosubmit: wpcarro <wpcarro@gmail.com>
Tested-by: BuildkiteCI
2022-03-01 02:07:51 +00:00

31 lines
803 B
Python

class Parser(object):
def __init__(self, tokens):
self.tokens = tokens
self.i = 0
def exhausted(self):
return self.i >= len(self.tokens)
def peek(self, n=0):
return self.tokens[self.i + n]
def advance(self):
if not self.exhausted():
self.i += 1
return self.peek(n=-1)
def match(self, xs):
if self.peek() in xs:
self.advance()
return True
return False
def test(self, predicate):
return predicate(self.tokens, self.i)
def expect(self, predicate):
if self.exhausted():
raise Exception("Unexpected EOL")
if predicate(self.peek()):
return self.advance()
raise Exception("Unexpected token: \"{}\"".format(self.peek()))