1 files changed, 55 insertions, 0 deletions
diff --git a/unix/boot/spp/rpp/ratlibr/amatch.r b/unix/boot/spp/rpp/ratlibr/amatch.r
new file mode 100644
index 00000000..54a2904b
--- /dev/null
+++ b/unix/boot/spp/rpp/ratlibr/amatch.r
@@ -0,0 +1,55 @@
+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