CHANGESTR.REX: Difference between revisions
(added a sample REXX code for the CHANGESTR subroutine. -- ~~~~) |
Walterpachl (talk | contribs) m (correct spelling(s)) |
||
Line 4:
║ original string (haystack)────────┐ │ │ [default: ≈ one billian]║
║ old string to be changed───┐ │ │ │ ┌───begin at this occurance #.║
║ {O, H, and N can be null.} │ │ │ │ │ [default: 1st
╚═╦════════════════════════════╗ │ │ │ │ │ ╔═══════════════════════╦═╝
╚════════════════════════════╝ ↓ ↓ ↓ ↓ ↓ ╚═══════════════════════╝*/
Line 13:
w=length(o) /*length of OLD string.*/
if w==0 & t\=0 then return n || h /*changing a null char ? */
#=0
do j=1 until # >= t /*keep changing, T times.*/
parse var h y (o) _ +(w) h /*parse the string ... */
Line 20:
else do
$=$ || y || n /*build new STR from S. */
#=#+1 /*bump
end
end /*j*/
|
Revision as of 12:08, 2 August 2013
<lang rexx>/*╔══════════════════════════════╗ CHANGESTR ╔═════════════════════════╗ ╔═╩══════════════════════════════╝ function ╚═════════════════════════╩═╗ ║ new string to be used──────────┐ ┌─────limit of # changes (times)║ ║ original string (haystack)────────┐ │ │ [default: ≈ one billian]║ ║ old string to be changed───┐ │ │ │ ┌───begin at this occurance #.║ ║ {O, H, and N can be null.} │ │ │ │ │ [default: 1st occurrence]║ ╚═╦════════════════════════════╗ │ │ │ │ │ ╔═══════════════════════╦═╝
╚════════════════════════════╝ ↓ ↓ ↓ ↓ ↓ ╚═══════════════════════╝*/
changestr: procedure; parse arg o,h,n,t,b /* T and B are optional.*/ $= /*$: the returned string.*/ t=word(t 999999999 , 1) /*maybe use the default? */ b=word(b 1 , 1) /* " " " " */ w=length(o) /*length of OLD string.*/ if w==0 & t\=0 then return n || h /*changing a null char ? */
- =0 /*# of changed occurrences*/
do j=1 until # >= t /*keep changing, T times.*/ parse var h y (o) _ +(w) h /*parse the string ... */ if _== then return $ || y /*no more left, return. */ if j<b then $=$ || y || o /*didn't meet begin at ? */ else do $=$ || y || n /*build new STR from S. */ #=#+1 /*bump occurrence number.*/ end end /*j*/ /*Most REXX BIFs only ···*/
return $ || h /* support three options.*/</lang>