RapidQ to
Hotbasic migration
Tips to help migrate a RapidQ project to Hotbasic
|
topic |
symptoms |
solutions |
|
Sub/Function declarations |
in HB subs must always be declared, even if
there are no forward calls (the sub statement itself isn’t used as a
declaration). If the sub has arguments, the definition HB uses is
the one in the declare statement (same for functions) |
add a declare statement
before the sub/function implementation |
|
variable
names in sub arguments must not be used elsewhere with a different type declare sub
a1(x as integer) declare sub
a2(x as long) will fail to compile. This is also true for API
declarations (although arguments are mere placeholders in this case) |
parse your code to avoid
duplicates (can be very tedious) |
|
|
Case-sensitivity |
HB is
case-sensitive, so that variable and function names must be exactly the same
throughout |
find/replace throughout
your code |
|
Reserved names |
some
names are reserved by HB and can’t be used. Non-exhaustive list includes: ss, c, StartPage using comment as a
variable name doesn’t generate a compile error but causes an error while
generating the object module |
find/replace throughout
your code |
|
Compilation directives |
$ifdef: $resource
inside $ifdefs are compiled anyway. As a result,
you can’t use $ifdef to select between different
resources $ifdef English $resource lang as
“english.txt” $else $resource lang as
“german.txt” $endif fails
to compile (duplicate resource declaration) |
? (no good solution so far) |
Errors in str$() results |
str$ sometimes yields strange results. str$ of an integer expression equal to 1 can return
0.999999999 problem
is difficult to isolate: doesn’t appear systematically and doesn’t seem to
appear on all computers |
a)
try
always calling str$ of a single variable: k=i+j
: print str$(k) rather
than: print
str$(i+j) (no guarantee that it eliminates all trouble) b) write your own conversion sub for integers so
you’re always safe |
Operator precedence |
Unlike
anyone else, HB gives + precedence over –. 4 – 3 + 1 is evaluated as: 4 – (3+1) and thus gives 0
instead of 2 Same
for *, which has precedence over / |
parse your code and ensure that + appears before –
in formulas. Same for * before / (very tedious) Use the $equalprec
on directive (this is a must,
immediately after $typecheck on) |
Ignoring function results |
HB
doesn’t allow ignoring function results, even for API functions (for which
the result is merely the value of EAX on return) E.g. sendmessage(h,WM_PAINT,0,0) fails to compile |
a)
if you
want to discard the result of a function, use a dummy variable to get the
result defint
dummy= sendmessage(h,WM_PAINT,0,0) b)
if
you always ignore the result of a given function, then declare it as a sub.
Also works for API functions: declare sub
SetFocus lib “user32” (h as integer) |
Unsupported window styles |
HB
doesn’t support some window style keywords (like borderstyle,
bevelinner, bevelouter, delbordericons) |
a)
border: Use HB’s keywords style
and exstyle to specify the border style you want.
Common styles you may want to use: b)
delbordericons: set the style bits explicitly in property .style: |