Example 9. Using Subscripted Substitution Symbols to Find Substrings

substr .macro start,strg1,strg2,pos .var len1,len2,i,tmp .if $symlen(start) = 0 .eval 1,start .endif .eval 0,pos .eval start,i .eval $symlen(strg1),len1 .eval $symlen(strg2),len2 .loop .break I = (len2 - len1 + 1) .asg ":strg2(i,len1):",tmp .if $symcmp(strg1,tmp) = 0 .eval i,pos .break .else .eval I + 1,i .endif .endloop .endm .asg 0,pos .asg "ar1 ar2 ar3 ar4",regs substr 1,"ar2",regs,pos .word pos