Compiling REx "\b(\w+)=(?|(\w+),(\d+)|(\d+);(\w+))\b"
Freeing REx: "\b(\w+)=(?|(\w+),(\d+)|(\d+);(\w+))\b"
Final program:
   1: BOUNDU (2)
   2: OPEN1 (4)
   4:   PLUS (6)
   5:     POSIXU[\w] (0)
   6: CLOSE1 (8)
   8: EXACT <=> (10)
  10: BRANCH (buf:1/3) (26)
  12:   OPEN2 (14)
  14:     PLUS (16)
  15:       POSIXU[\w] (0)
  16:   CLOSE2 (18)
  18:   EXACT <,> (20)
  20:   OPEN3 (22)
  22:     PLUS (24)
  23:       POSIXU[\d] (0)
  24:   CLOSE3 (43)
  26: BRANCH (buf:3/5) (FAIL)
  28:   OPEN2/4 (30)
  30:     PLUS (32)
  31:       POSIXU[\d] (0)
  32:   CLOSE2/4 (34)
  34:   EXACT <;> (36)
  36:   OPEN3/5 (38)
  38:     PLUS (40)
  39:       POSIXU[\w] (0)
  40:   CLOSE3/5 (43)
  42: TAIL (43)
  43: BOUNDU (44)
  44: END (0)
floating "=" at 1..9223372036854775807 (checking floating) stclass BOUNDU minlen 5
Matching REx "\b(\w+)=(?|(\w+),(\d+)|(\d+);(\w+))\b" against "aa=AA,123 bb=123;dd"
Intuit: trying to determine minimum start position...
  doing 'check' fbm scan, [1..16] gave 2
  Found floating substr "=" at offset 2 (rx_origin now 0)...
  (multiline anchor test skipped)
  looking for class: start_shift: 1 check_at: 2 rx_origin: 0 endpos: 2
  Does not contradict STCLASS...
Intuit: Successfully guessed: match at offset 0
Matching stclass BOUNDU against "aa=AA,123 bb=12" (15 bytes)
   0 <> <aa=AA,123 >         |   0| 1:BOUNDU(2)
   0 <> <aa=AA,123 >         |   0| 2:OPEN1(4)
   0 <> <aa=AA,123 >         |   0| 4:PLUS(6)
                             |   0| POSIXU[\w] can match 2 times out of 2147483647...
   2 <aa> <=AA,123 bb>       |   1|  6:CLOSE1(8)
   2 <aa> <=AA,123 bb>       |   1|  8:EXACT <=>(10)
   3 <aa=> <AA,123 bb=>      |   1|  10:BRANCH (buf:1/3)(26)
   3 <aa=> <AA,123 bb=>      |   2|   12:OPEN2(14)
   3 <aa=> <AA,123 bb=>      |   2|   14:PLUS(16)
                             |   2|   POSIXU[\w] can match 2 times out of 2147483647...
   5 <aa=AA> <,123 bb=12>    |   3|    16:CLOSE2(18)
   5 <aa=AA> <,123 bb=12>    |   3|    18:EXACT <,>(20)
   6 <a=AA,> <123 bb=123>    |   3|    20:OPEN3(22)
   6 <a=AA,> <123 bb=123>    |   3|    22:PLUS(24)
                             |   3|    POSIXU[\d] can match 3 times out of 2147483647...
   9 <A,123> < bb=123;dd>    |   4|     24:CLOSE3(43)
   9 <A,123> < bb=123;dd>    |   4|     43:BOUNDU(44)
   9 <A,123> < bb=123;dd>    |   4|     44:END(0)
Match successful!
("aa", "AA", "123")
Matching REx "\b(\w+)=(?|(\w+),(\d+)|(\d+);(\w+))\b" against " bb=123;dd"
Intuit: trying to determine minimum start position...
  doing 'check' fbm scan, [10..16] gave 12
  Found floating substr "=" at offset 12 (rx_origin now 9)...
  (multiline anchor test skipped)
  looking for class: start_shift: 1 check_at: 12 rx_origin: 9 endpos: 12
  Does not contradict STCLASS...
Intuit: Successfully guessed: match at offset 9
Matching stclass BOUNDU against " bb=12" (6 bytes)
   9 <A,123> < bb=123;dd>    |   0| 1:BOUNDU(2)
   9 <A,123> < bb=123;dd>    |   0| 2:OPEN1(4)
   9 <A,123> < bb=123;dd>    |   0| 4:PLUS(6)
                             |   0| POSIXU[\w] can match 0 times out of 2147483647...
                             |   0| failed...
  10 <,123 > <bb=123;dd>     |   0| 1:BOUNDU(2)
  10 <,123 > <bb=123;dd>     |   0| 2:OPEN1(4)
  10 <,123 > <bb=123;dd>     |   0| 4:PLUS(6)
                             |   0| POSIXU[\w] can match 2 times out of 2147483647...
  12 <23 bb> <=123;dd>       |   1|  6:CLOSE1(8)
  12 <23 bb> <=123;dd>       |   1|  8:EXACT <=>(10)
  13 <23 bb=> <123;dd>       |   1|  10:BRANCH (buf:1/3)(26)
  13 <23 bb=> <123;dd>       |   2|   12:OPEN2(14)
  13 <23 bb=> <123;dd>       |   2|   14:PLUS(16)
                             |   2|   POSIXU[\w] can match 3 times out of 2147483647...
                             |   2|   failed...
  13 <23 bb=> <123;dd>       |   1|  26:BRANCH (buf:3/5)(42)
  13 <23 bb=> <123;dd>       |   2|   28:OPEN2/4(30)
  13 <23 bb=> <123;dd>       |   2|   30:PLUS(32)
                             |   2|   POSIXU[\d] can match 3 times out of 2147483647...
  16 <23 bb=123> <;dd>       |   3|    32:CLOSE2/4(34)
  16 <23 bb=123> <;dd>       |   3|    34:EXACT <;>(36)
  17 <23 bb=123;> <dd>       |   3|    36:OPEN3/5(38)
  17 <23 bb=123;> <dd>       |   3|    38:PLUS(40)
                             |   3|    POSIXU[\w] can match 2 times out of 2147483647...
  19 <23 bb=123;dd> <>       |   4|     40:CLOSE3/5(43)
  19 <23 bb=123;dd> <>       |   4|     43:BOUNDU(44)
  19 <23 bb=123;dd> <>       |   4|     44:END(0)
Match successful!
("bb", "123", "dd")
Matching REx "\b(\w+)=(?|(\w+),(\d+)|(\d+);(\w+))\b" against ""
Regex match can't succeed, so not even tried
Matching REx "\b(\w+)=(?|(\w+),(\d+)|(\d+);(\w+))\b" against "aa=AA,123 bb=123;dd"
Intuit: trying to determine minimum start position...
  doing 'check' fbm scan, [1..16] gave 2
  Found floating substr "=" at offset 2 (rx_origin now 0)...
  (multiline anchor test skipped)
  looking for class: start_shift: 1 check_at: 2 rx_origin: 0 endpos: 2
  Does not contradict STCLASS...
Intuit: Successfully guessed: match at offset 0
Matching stclass BOUNDU against "aa=AA,123 bb=12" (15 bytes)
   0 <> <aa=AA,123 >         |   0| 1:BOUNDU(2)
   0 <> <aa=AA,123 >         |   0| 2:OPEN1(4)
   0 <> <aa=AA,123 >         |   0| 4:PLUS(6)
                             |   0| POSIXU[\w] can match 2 times out of 2147483647...
   2 <aa> <=AA,123 bb>       |   1|  6:CLOSE1(8)
   2 <aa> <=AA,123 bb>       |   1|  8:EXACT <=>(10)
   3 <aa=> <AA,123 bb=>      |   1|  10:BRANCH (buf:1/3)(26)
   3 <aa=> <AA,123 bb=>      |   2|   12:OPEN2(14)
   3 <aa=> <AA,123 bb=>      |   2|   14:PLUS(16)
                             |   2|   POSIXU[\w] can match 2 times out of 2147483647...
   5 <aa=AA> <,123 bb=12>    |   3|    16:CLOSE2(18)
   5 <aa=AA> <,123 bb=12>    |   3|    18:EXACT <,>(20)
   6 <a=AA,> <123 bb=123>    |   3|    20:OPEN3(22)
   6 <a=AA,> <123 bb=123>    |   3|    22:PLUS(24)
                             |   3|    POSIXU[\d] can match 3 times out of 2147483647...
   9 <A,123> < bb=123;dd>    |   4|     24:CLOSE3(43)
   9 <A,123> < bb=123;dd>    |   4|     43:BOUNDU(44)
   9 <A,123> < bb=123;dd>    |   4|     44:END(0)
Match successful!
Matching REx "\b(\w+)=(?|(\w+),(\d+)|(\d+);(\w+))\b" against " bb=123;dd"
Intuit: trying to determine minimum start position...
  doing 'check' fbm scan, [10..16] gave 12
  Found floating substr "=" at offset 12 (rx_origin now 9)...
  (multiline anchor test skipped)
  looking for class: start_shift: 1 check_at: 12 rx_origin: 9 endpos: 12
  Does not contradict STCLASS...
Intuit: Successfully guessed: match at offset 9
Matching stclass BOUNDU against " bb=12" (6 bytes)
   9 <A,123> < bb=123;dd>    |   0| 1:BOUNDU(2)
   9 <A,123> < bb=123;dd>    |   0| 2:OPEN1(4)
   9 <A,123> < bb=123;dd>    |   0| 4:PLUS(6)
                             |   0| POSIXU[\w] can match 0 times out of 2147483647...
                             |   0| failed...
  10 <,123 > <bb=123;dd>     |   0| 1:BOUNDU(2)
  10 <,123 > <bb=123;dd>     |   0| 2:OPEN1(4)
  10 <,123 > <bb=123;dd>     |   0| 4:PLUS(6)
                             |   0| POSIXU[\w] can match 2 times out of 2147483647...
  12 <23 bb> <=123;dd>       |   1|  6:CLOSE1(8)
  12 <23 bb> <=123;dd>       |   1|  8:EXACT <=>(10)
  13 <23 bb=> <123;dd>       |   1|  10:BRANCH (buf:1/3)(26)
  13 <23 bb=> <123;dd>       |   2|   12:OPEN2(14)
  13 <23 bb=> <123;dd>       |   2|   14:PLUS(16)
                             |   2|   POSIXU[\w] can match 3 times out of 2147483647...
                             |   2|   failed...
  13 <23 bb=> <123;dd>       |   1|  26:BRANCH (buf:3/5)(42)
  13 <23 bb=> <123;dd>       |   2|   28:OPEN2/4(30)
  13 <23 bb=> <123;dd>       |   2|   30:PLUS(32)
                             |   2|   POSIXU[\d] can match 3 times out of 2147483647...
  16 <23 bb=123> <;dd>       |   3|    32:CLOSE2/4(34)
  16 <23 bb=123> <;dd>       |   3|    34:EXACT <;>(36)
  17 <23 bb=123;> <dd>       |   3|    36:OPEN3/5(38)
  17 <23 bb=123;> <dd>       |   3|    38:PLUS(40)
                             |   3|    POSIXU[\w] can match 2 times out of 2147483647...
  19 <23 bb=123;dd> <>       |   4|     40:CLOSE3/5(43)
  19 <23 bb=123;dd> <>       |   4|     43:BOUNDU(44)
  19 <23 bb=123;dd> <>       |   4|     44:END(0)
Match successful!
("", "aa", "AA", "123", undef, undef, " ", "bb", undef, undef, "123", "dd")
Freeing REx: "\b(\w+)=(?|(\w+),(\d+)|(\d+);(\w+))\b"