+- QB64 Phoenix Edition (https://staging.qb64phoenix.com)
+-- Forum: QB64 Rising (https://staging.qb64phoenix.com/forumdisplay.php?fid=1)
+--- Forum: Prolific Programmers (https://staging.qb64phoenix.com/forumdisplay.php?fid=26)
+---- Forum: SMcNeill (https://staging.qb64phoenix.com/forumdisplay.php?fid=29)
+---- Thread: Self-Referencing Customtype Libraries (/showthread.php?tid=139)
Self-Referencing Customtype Libraries - SMcNeill - 04-23-2022
Just something rather neat that I thought I'd share, even if I haven't honestly sorted out an use for it (yet)...
Code: (Select All)
DECLARE CUSTOMTYPE LIBRARY 'Use Customtype for self-referencing a sub written inside your program
SUB SUB_EXAMPLE (BYVAL passed AS _OFFSET) 'this points to SUB EXAMPLE below, but uses an OFFSET to point to its parameter.
'NOTE: The sub/function name *MUST* be the same as QB64 translates it as, for us.
'General rule of thumb is to make the subname ALL CAPS, preceeded by SUB_ or FUNCTION_ as dictated.
SUB SUB_EXAMPLE2 (BYVAL passed AS _OFFSET)
END DECLARE
TYPE DataType 'A datatype to use as an example
x AS STRING * 12
y AS LONG
z AS LONG
END TYPE
TYPE DataType2 'a second datatype
byte1 AS _UNSIGNED _BYTE
byte2 AS _UNSIGNED _BYTE
byte3 AS _UNSIGNED _BYTE
byte4 AS _UNSIGNED _BYTE
byte5 AS _UNSIGNED _BYTE
byte6 AS _UNSIGNED _BYTE
byte7 AS _UNSIGNED _BYTE
byte8 AS _UNSIGNED _BYTE
byte9 AS _UNSIGNED _BYTE
byte10 AS _UNSIGNED _BYTE
byte11 AS _UNSIGNED _BYTE
byte12 AS _UNSIGNED _BYTE
byte13 AS _UNSIGNED _BYTE
byte14 AS _UNSIGNED _BYTE
byte15 AS _UNSIGNED _BYTE
byte16 AS _UNSIGNED _BYTE
byte17 AS _UNSIGNED _BYTE
byte18 AS _UNSIGNED _BYTE
byte19 AS _UNSIGNED _BYTE
byte20 AS _UNSIGNED _BYTE
END TYPE
DIM m AS _MEM 'A memblock to store some information
m = _MEMNEW(20) 'The proper size to fill the data type that we're interested in passing back to our program.
_MEMPUT m, m.OFFSET, "Hello World" '12 bytes
_MEMPUT m, m.OFFSET + 12, -2 AS LONG '4 more
_MEMPUT m, m.OFFSET + 16, 3 AS LONG '4 more to make all 20
SUB_EXAMPLE m.OFFSET 'Call the sub with the offset to these 20 bytes of memory
SLEEP
SUB_EXAMPLE2 m.OFFSET 'Notice, we passed the same block of memory, but are handling it differently here,
' according to the paramters set in the second sub
_MEMFREE m
END
SUB Example (t AS DataType) 'And here, we want to set up the actual sub to work with our example datatype.
PRINT t.x 'print the values of that memblock
PRINT t.y
PRINT t.z
END SUB
SUB Example2 (x AS DataType2)
COLOR 12
PRINT x.byte1
PRINT x.byte2
PRINT x.byte3
PRINT x.byte4
PRINT x.byte5
PRINT x.byte6
PRINT x.byte7
PRINT x.byte8
PRINT x.byte9
PRINT x.byte10
PRINT x.byte11
PRINT x.byte12
PRINT x.byte13
PRINT x.byte14
PRINT x.byte15
PRINT x.byte16
PRINT x.byte17
PRINT x.byte18
PRINT x.byte19
PRINT x.byte20
END SUB