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| from __future__ import unicode_literals | |
| import unittest | |
| from io import StringIO | |
| import string | |
| from .. import Scanning | |
| from ..Symtab import ModuleScope | |
| from ..TreeFragment import StringParseContext | |
| from ..Errors import init_thread | |
| # generate some fake code - just a bunch of lines of the form "a0 a1 ..." | |
| code = [] | |
| for ch in string.ascii_lowercase: | |
| line = " ".join(["%s%s" % (ch, n) for n in range(10)]) | |
| code.append(line) | |
| code = "\n".join(code) | |
| init_thread() | |
| class TestScanning(unittest.TestCase): | |
| def make_scanner(self): | |
| source = Scanning.StringSourceDescriptor("fake code", code) | |
| buf = StringIO(code) | |
| context = StringParseContext("fake context") | |
| scope = ModuleScope("fake_module", None, None) | |
| return Scanning.PyrexScanner(buf, source, scope=scope, context=context) | |
| def test_put_back_positions(self): | |
| scanner = self.make_scanner() | |
| self.assertEqual(scanner.sy, "IDENT") | |
| self.assertEqual(scanner.systring, "a0") | |
| scanner.next() | |
| self.assertEqual(scanner.sy, "IDENT") | |
| self.assertEqual(scanner.systring, "a1") | |
| a1pos = scanner.position() | |
| self.assertEqual(a1pos[1:], (1, 3)) | |
| a2peek = scanner.peek() # shouldn't mess up the position | |
| self.assertEqual(a1pos, scanner.position()) | |
| scanner.next() | |
| self.assertEqual(a2peek, (scanner.sy, scanner.systring)) | |
| # find next line | |
| while scanner.sy != "NEWLINE": | |
| scanner.next() | |
| line_sy = [] | |
| line_systring = [] | |
| line_pos = [] | |
| scanner.next() | |
| while scanner.sy != "NEWLINE": | |
| line_sy.append(scanner.sy) | |
| line_systring.append(scanner.systring) | |
| line_pos.append(scanner.position()) | |
| scanner.next() | |
| for sy, systring, pos in zip( | |
| line_sy[::-1], line_systring[::-1], line_pos[::-1] | |
| ): | |
| scanner.put_back(sy, systring, pos) | |
| n = 0 | |
| while scanner.sy != "NEWLINE": | |
| self.assertEqual(scanner.sy, line_sy[n]) | |
| self.assertEqual(scanner.systring, line_systring[n]) | |
| self.assertEqual(scanner.position(), line_pos[n]) | |
| scanner.next() | |
| n += 1 | |
| self.assertEqual(n, len(line_pos)) | |
| def test_tentatively_scan(self): | |
| scanner = self.make_scanner() | |
| with Scanning.tentatively_scan(scanner) as errors: | |
| while scanner.sy != "NEWLINE": | |
| scanner.next() | |
| self.assertFalse(errors) | |
| scanner.next() | |
| self.assertEqual(scanner.systring, "b0") | |
| pos = scanner.position() | |
| with Scanning.tentatively_scan(scanner) as errors: | |
| while scanner.sy != "NEWLINE": | |
| scanner.next() | |
| if scanner.systring == "b7": | |
| scanner.error("Oh no not b7!") | |
| break | |
| self.assertTrue(errors) | |
| self.assertEqual(scanner.systring, "b0") # state has been restored | |
| self.assertEqual(scanner.position(), pos) | |
| scanner.next() | |
| self.assertEqual(scanner.systring, "b1") # and we can keep going again | |
| scanner.next() | |
| self.assertEqual(scanner.systring, "b2") # and we can keep going again | |
| with Scanning.tentatively_scan(scanner) as error: | |
| scanner.error("Something has gone wrong with the current symbol") | |
| self.assertEqual(scanner.systring, "b2") | |
| scanner.next() | |
| self.assertEqual(scanner.systring, "b3") | |
| # test a few combinations of nested scanning | |
| sy1, systring1 = scanner.sy, scanner.systring | |
| pos1 = scanner.position() | |
| with Scanning.tentatively_scan(scanner): | |
| scanner.next() | |
| sy2, systring2 = scanner.sy, scanner.systring | |
| pos2 = scanner.position() | |
| with Scanning.tentatively_scan(scanner): | |
| with Scanning.tentatively_scan(scanner): | |
| scanner.next() | |
| scanner.next() | |
| scanner.error("Ooops") | |
| self.assertEqual((scanner.sy, scanner.systring), (sy2, systring2)) | |
| self.assertEqual((scanner.sy, scanner.systring), (sy2, systring2)) | |
| scanner.error("eee") | |
| self.assertEqual((scanner.sy, scanner.systring), (sy1, systring1)) | |
| with Scanning.tentatively_scan(scanner): | |
| scanner.next() | |
| scanner.next() | |
| with Scanning.tentatively_scan(scanner): | |
| scanner.next() | |
| # no error - but this block should be unwound by the outer block too | |
| scanner.next() | |
| scanner.error("Oooops") | |
| self.assertEqual((scanner.sy, scanner.systring), (sy1, systring1)) | |
| if __name__ == "__main__": | |
| unittest.main() | |