diff options
| -rw-r--r-- | doc/documentation.tex | 7 | ||||
| -rw-r--r-- | src/MaskUtils.c | 5 |
2 files changed, 8 insertions, 4 deletions
diff --git a/doc/documentation.tex b/doc/documentation.tex index 349de9b..d6adc5d 100644 --- a/doc/documentation.tex +++ b/doc/documentation.tex @@ -199,9 +199,12 @@ bitmask corresponding to the given type or state. For example, if a given type uses three bits of the mask, the returned value could be the integer corresponding to the bitfield $001110000$\ldots, where the location of $1$s indicates the bits which have been allocated to the -given type. A return value of $0$ indicates that the bitmask could +given type. A return value of $-1$ indicates that the bitmask could not be determined for some reason (for example, the requested state -was not previously registered). +was not previously registered)\footnote{Note that a potential +ambiguity arises here, in that if the full mask is allocated to a +single type, then $-1$ is a valid state. It is assumed that this +eventuality won't arise in practice.}. The following macros have been defined for fast setting and checking of the mask by direct bitwise operations: diff --git a/src/MaskUtils.c b/src/MaskUtils.c index ad9e5e6..784f5b0 100644 --- a/src/MaskUtils.c +++ b/src/MaskUtils.c @@ -422,7 +422,8 @@ SpaceMask_GetTypeBits(const char* type_name) @author Denis Pollney @date 15 October 2002 @desc - Returns the bitmask corresponding to the given state. + Returns the bitmask corresponding to the given state, or + -1 if the state does not exist. @enddesc @@*/ @@ -449,7 +450,7 @@ SpaceMask_GetStateBits(const char* type_name, const char* state_name) "Requested state \"%s\" could not be found in type \"%s\"\n", state_name, type_name); - return 0; + return -1; } /*@@ |