Expressions like (a++ b), (a ~b), (a++ ~b), (a++ --b) were accepted by the expression parser but caused errors in the code generator. These manifested as compiler errors, such as:
*** Compiler error: SR error: emitter stack overfull
*** Compiler error: SR error: Attempt to remove a nonexistent bracket layer from the emitter stack
All these expressions are invalid. (With the possible exception of (a++ -b), which could be valid if the - were a binary operator, but Inform treats it as unary.)
To handle this, I expanded the prec_table[] in expressp.c to have separate rows and columns for prefix, binary, and postfix operators. (Previously it had just one row and column for all operators.) The bad cases now have the entry NOOP_E, which indicates an expression parsing error.
(NOOP_E is glossed as "missing operator" because the most likely cause is a missing binary operator. That is, you could make the above examples valid by adding a + sign: (a++ + b), (a + ~b), (a++ + ~b), (a++ + --b).)
Fixes https://github.com/DavidKinder/Inform6/issues/248 .
Expressions like
(a++ b),(a ~b),(a++ ~b),(a++ --b)were accepted by the expression parser but caused errors in the code generator. These manifested as compiler errors, such as:All these expressions are invalid. (With the possible exception of
(a++ -b), which could be valid if the-were a binary operator, but Inform treats it as unary.)To handle this, I expanded the prec_table[] in expressp.c to have separate rows and columns for prefix, binary, and postfix operators. (Previously it had just one row and column for all operators.) The bad cases now have the entry NOOP_E, which indicates an expression parsing error.
(NOOP_E is glossed as "missing operator" because the most likely cause is a missing binary operator. That is, you could make the above examples valid by adding a
+sign:(a++ + b),(a + ~b),(a++ + ~b),(a++ + --b).)Test cases: https://github.com/erkyrath/Inform6-Testing/blob/unaryop-err/src/unaryop_err_test.inf
Incidental changes:
I renamed the error constants
e1,e2, etc to have more meaningful names. Same goes for the-1table entry.The prec_table[] is now 7x7, which makes it a bit too wide for the source's normal 80-character formatting. Sorry!
The compiler error "Missing operator: inserting '+'" now reads "Missing operator after ..."
The trace message "Adding bracket layer" now shows the
depthargument.