fix validation

[mzuenni]

correctly verify which of the .in .ans and .out files inside the invalid_* directories should be rejected

[thorehusfeldt]

Here is a toy program to test invalidation (and constraints):
pickanumber.zip

It has several validators:

pickanumber> tree *_validator*
answer_validators
└── answerformat.py
input_validators
├── invala
│   ├── validate.cpp
│   └── validation.h
└── invalb
    ├── validate.cpp
    └── validation.h
output_validator
└── validate.py

5 directories, 6 files

You can run

bt generate --no-validators
bt validate --v --invalid

Here is the current output, with parallelisation switched off:

Much of this look ok. Note, e.g., that testcase neg_b passes the first input validator (invala) only to be rejected by the other invalb, which is therefore green. Testcases named actually_valid should trigger red lines; they were (deliberately) misplaced into invalid_ in order to check that invalidation works. Every validator is run on every testcase at most once.

But, while we’re here:

1. I am not sure why invalb is run on too_many_tokens, there is no reason for that (invala just rejected it, as expected.)

2. Also, for invalid_outputs/just_plain_wrong, both input and answer validation are expected to pass, so those lines should be green (not yellow).

3. When the (singular) output_validator accepts invalid_outputs/actually_valid, it should be red, not yellow. The preceding three lines should be green, not yellow (their behaviour is expected.)

[thorehusfeldt]

Looks good to me.