Oxygen Basic
Programming => Bugs & Feature Requests => Topic started by: pber on June 21, 2014, 06:50:57 AM
-
hi charles,
i'm writing some test functions that make use of compile/call
assert quote -- mid("123",1,1) = "1" --
assert quote -- "1" = mid("123",1,1) --
the 2nd row crashes.
The code evaluated is something like
basic
if not ( "1" = mid("123",1,1) ) then
assertErr=-1
end if
-
Hi Paolo, Can you give more details?
-
hi Charles,
it seems it crashes only when printing a string.
The initial code I used was similar to this one
int assertError=0
string src= quote ||
if not ( "2" = mid("123",2,1) ) then
assertError= -1
endif
||
sys p= compile(src)
call p
print assertError
print "ok"
the print with assertError pass,
the one with "ok" generates gpf
Now I worked around this problem by assigning
the 2 values to be compared to 2 different sys vars,
then testing. This way the problem does not occur.
.
-
...my mini-asserts have some problem with UDF
this does not work:
function mySqrt(int n)
return sqrt(n)
end function
assertEQ "3" , "mySqrt(9)"
-
oh... code evaluated by compile
does not see outer functions, only variables :(
-
There is a simple workaround for most things :)
The solution is to use a vectored function, wherebye the function address is stored in a variable, which is visible to your dynamic code.
declare *foo()
@foo=@foofun
function foofun() as sys, label
===============================
print "foo!"
end function
declare *foo()
@foo=@foofun
function DynExec(string src)
============================
sys c=compile src
string er=error
if er then
print "DynExec:" er
else
call c
end if
freememory c
end function
DynExec "foo()"
-
Great!
What does label mean?
...
function foofun() as sys, label
...Your example works even without it.
Your example implies the compiled code must use a different syntax
(i.e. function names in compiled code are different
from the "production" code).
Oxygen does not implement namespace, and scope is anonymous.
Maybe I could implement a module-system like this:
' here i want to be sure that functions
' are still callable (even if not exported outside the module)
sub worker_function()
print "I'm just an anonymous worker"
end sub
function entry_function() as sys ', label
worker_function
end function
type fun_module
sys (* f1)()
''''''''''''''''''''''''''
' next 2 do not work (...don't they declare a name?)
'declare *f1() as sys
'! * f1() as sys
end type
' declare and initialize module <fun>
dim fun as fun_module
@fun.f1= @entry_function
function DynExec(string src)
============================
sys c=compile src
string er=error
if er then
print "DynExec:" er
else
call c
end if
freememory c
end function
DynExec "fun.f1()"
Do exist a better way?
-
Dynamically compiled code has the same syntax as statically compiled code, though there are constraints on the visibility of host functions variables. It's somewhat like a DLL.
OxygenBasic does not have namespaces but scopes are available to confine visibility, without requiring procedures.
sys a=42
scope
sys a=24
print a '24
end scope
print a '42
Procedures can also be defined inside procedures, if you need to confine them.
function f(sys a,b) as sys
sys c=45
'
function g() as sys
return a+b+c
end function
'
return g()
end function
print f 100,200 'result 345
-
Not to forget classes as the optimal construct for encapsulation:
class fruit
===========
sys skin,flesh,seed
method juice()
print "Juice!"
end method
end class
fruit apple
fruit.juice()
-
class fruit
Hi Charles
Is a joke, isn't it ;D
.
-
Oh, deadly serious :)
Classes and their methods are directly visible to dynamically compiled code. No need to setup a vectored function as above:
class fruit
===========
sys skin,flesh,seed
method juice()
print "Juice!"
end method
end class
function DynExec(string src)
============================
sys c
c=compile src
string er=error
if er then
print "DynExec:" er
else
call c
end if
freememory c
end function
DynExec "fruit pear : pear.juice" 'Juice!
-
Right: using class make things simpler.
thanks Charles.
-
Is a joke, isn't it
Oops, no joke.
-
Oxygen is not a joke.
Without tests i'm not able to move one step ahead,
using classes and objects do not make things easier.
...i feel like they do just what they want, not what i say to do