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include defs
# amatch --- (non-recursive) look for match starting at lin (from)
integer function amatch (lin, from, pat, tagbeg, tagend)
character lin (MAXLINE), pat (MAXPAT)
integer from, tagbeg (10), tagend (10)
integer i, j, offset, stack
integer omatch, patsiz
for (i = 1; i <= 10; i = i + 1) {
tagbeg (i) = 0
tagend (i) = 0
}
tagbeg (1) = from
stack = 0
offset = from # next unexamined input character
for (j = 1; pat (j) != EOS; j = j + patsiz (pat, j))
if (pat (j) == CLOSURE) { # a closure entry
stack = j
j = j + CLOSIZE # step over CLOSURE
for (i = offset; lin (i) != EOS; ) # match as many as
if (omatch (lin, i, pat, j) == NO) # possible
break
pat (stack + COUNT) = i - offset
pat (stack + START) = offset
offset = i # character that made us fail
}
else if (pat (j) == START_TAG) {
i = pat (j + 1)
tagbeg (i + 1) = offset
}
else if (pat (j) == STOP_TAG) {
i = pat (j + 1)
tagend (i + 1) = offset
}
else if (omatch (lin, offset, pat, j) == NO) { # non-closure
for ( ; stack > 0; stack = pat (stack + PREVCL))
if (pat (stack + COUNT) > 0)
break
if (stack <= 0) { # stack is empty
amatch = 0 # return failure
return
}
pat (stack + COUNT) = pat (stack + COUNT) - 1
j = stack + CLOSIZE
offset = pat (stack + START) + pat (stack + COUNT)
}
# else omatch succeeded
amatch = offset
tagend (1) = offset
return # success
end
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