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CHANGESTR.REX: Difference between revisions
m
→the CHANGESTR source: changed some comments (to align better for perusing).
m (→the CHANGESTR source: changed a comment to reflect its IF statement.) |
m (→the CHANGESTR source: changed some comments (to align better for perusing).) |
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╚═════════════════════════════╝ │ │ │ │ │ │ ╚═══════════════════════════╝
↓ ↓ ↓ ↓ ↓ ↓ */
changestr: parse arg o,h,n,t,b,p,
/*T, B, P are optional ►─┘*/
t=word(t 999999999, 1) /*maybe use the default? */
b=word(b 1 , 1) /* " " " " */
Line 38 ⟶ 39:
if \datatype(t, 'W') then signal syntax /*4th arg not an integer. */
if \datatype(b, 'W') then signal syntax /*5th " " " " */
if \datatype(p, 'W') then signal syntax /*6th
if t<0 then signal syntax /*4th
if b<1 then signal syntax /*5th
if p<1 then signal syntax /*6th " " " */
L=length(o) /*length of OLD string. */
if L==0 & t\=0 then return n || h /*changing a [null] char?
if p\=1 then do /*P¬=1? Then ajust F & H.*/
f=left(h, min(p-1, length(h))) /*keep first part intact. */
h=substr(h, p) /*only use this part of H.*/
Line 53 ⟶ 55:
if _=='' then return f || $ || y /*no more left, return. */
$=$ || y /*append the residual txt.*/
/* [↓] check if too soon.*/
if j<b then $=$ || o /*append OLD if too soon. */
else do /*met the occurrence test.*/
$=$ || n /*append the NEW string.*/
#=#+1 /*bump
end /* [↑] append new string.*/
end /*j*/ /*Note: most REXX ··· */
/* CHANGESTR BIFs only ···*/
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