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| author | Robin Haberkorn <robin.haberkorn@googlemail.com> | 2024-11-25 18:58:53 +0300 |
|---|---|---|
| committer | Robin Haberkorn <robin.haberkorn@googlemail.com> | 2024-11-25 18:58:53 +0300 |
| commit | 5597bc72671d0128e6f0dba446c4dc8d47bf37d0 (patch) | |
| tree | ed8b93c4003c10a64f2eab6f8a304a838a632209 | |
| parent | 726847bdf3250e235c97c451a6ab466b3e9103f2 (diff) | |
| download | sciteco-5597bc72671d0128e6f0dba446c4dc8d47bf37d0.tar.gz | |
fixed subtle operator precedence bug
* It was possible to provoke operator right-associativity when placing a high-precedence
operator between two low-precedence operators.
1-6*5-1 evaluated to -28 instead of the expected -30.
* The reason is that SciTECO relies on operators to be resolved from left-to-right as soon as possible.
The higher precedence operator prevents that and pushing the 2nd "-" only evaluated 6*5.
At the end 1-30-1 would be left on the stack.
teco_expressions_eval() however evaluates from right-to-left which is wrong in this case.
* Instead, we now do a full eval on every operator with a lower precedence, making sure that 1-30 is
evaluated first.
| -rw-r--r-- | src/expressions.c | 2 | ||||
| -rw-r--r-- | tests/testsuite.at | 6 |
2 files changed, 7 insertions, 1 deletions
diff --git a/src/expressions.c b/src/expressions.c index 25213e9..2424fb3 100644 --- a/src/expressions.c +++ b/src/expressions.c @@ -145,7 +145,7 @@ teco_expressions_push_calc(teco_operator_t op, GError **error) /* calculate if op has lower precedence than op on stack */ if (first >= 0 && teco_expressions_precedence(op) <= teco_expressions_precedence(teco_expressions_peek_op(first)) && - !teco_expressions_calc(error)) + !teco_expressions_eval(FALSE, error)) return FALSE; teco_expressions_push_op(op); diff --git a/tests/testsuite.at b/tests/testsuite.at index 59b1041..74df3a0 100644 --- a/tests/testsuite.at +++ b/tests/testsuite.at @@ -52,6 +52,12 @@ AT_SETUP([Missing left operand]) AT_CHECK([$SCITECO -e '+23='], 1, ignore, ignore) AT_CLEANUP +AT_SETUP([Operator precedence]) +AT_CHECK([$SCITECO -e "(1-6*5)+29\"N(0/0)'"], 0, ignore, ignore) +AT_CHECK([$SCITECO -e "(1-6*5-1)+30\"N(0/0)'"], 0, ignore, ignore) +AT_CHECK([$SCITECO -e "(1-6*5-1*2)+31\"N(0/0)'"], 0, ignore, ignore) +AT_CLEANUP + AT_SETUP([Closing loops at the correct macro level]) AT_CHECK([$SCITECO -e '@^Ua{>} <Ma'], 1, ignore, ignore) AT_CLEANUP |