CURSOR/DOWHILE
Generic cursor walker.
Input stack: cursor closure iterator
Output stack:
CURSOR/DOWHILE will execute closure while it leaves 1 on
top of the stack, invoking iterator on the cursor after each run.
The closure should be written with the expectation of the cursor on the top of the stack.
PumpkinDB> ["testkey" HLC CONCAT 1 ASSOC
"testkey" HLC CONCAT 2 ASSOC
"testkey" HLC CONCAT 3 ASSOC
"z" HLC CONCAT 4 ASSOC
COMMIT] WRITE
[CURSOR DUP CURSOR/FIRST DROP
[CURSOR/VAL TRUE] 'CURSOR/NEXT CURSOR/DOWHILE] READ
0x01 0x02 0x03 0x04
Allocation
Allocates for closure composition
Errors
NoTransaction error if there's no current write transaction
InvalidValue error if the cursor identifier is incorrect or expired
Tests
cursor_dowhile :
["testkey" HLC CONCAT 1 ASSOC
"testkey" HLC CONCAT 2 ASSOC
"testkey" HLC CONCAT 3 ASSOC
"z" HLC CONCAT 4 ASSOC
COMMIT] WRITE
[CURSOR DUP CURSOR/FIRST DROP
[CURSOR/VAL TRUE] 'CURSOR/NEXT CURSOR/DOWHILE] READ
4 WRAP [1 2 3 4] EQUAL?.