C:\junk>perl noname.pl Compiling REx `a*b' size 6 Got 52 bytes for offset annotations. first at 1 synthetic stclass `ANYOF[ab]'. 1: STAR(4) 2: EXACT (0) 4: EXACT (6) 6: END(0) floating `b' at 0..2147483647 (checking floating) stclass `ANYOF[ab]' minlen 1 Offsets: [6] 2[1] 1[1] 0[0] 3[1] 0[0] 4[0] Guessing start of match, REx `a*b' against `aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa...'... Did not find floating substr `b'... Match rejected by optimizer Hello Freeing REx: `"a*b"' C:\junk>perl noname.pl Compiling REx `a*[b]' size 15 Got 124 bytes for offset annotations. first at 1 synthetic stclass `ANYOF[ab]'. 1: STAR(4) 2: EXACT (0) 4: ANYOF[b](15) 15: END(0) stclass `ANYOF[ab]' minlen 1 Offsets: [15] 2[1] 1[1] 0[0] 3[3] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 6[0] Matching REx `a*[b]' against `aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa...' Matching stclass `ANYOF[ab]' against `aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa' Setting an EVAL scope, savestack=3 0 <> | 1: STAR EXACT can match 61 times out of 2147483647... Setting an EVAL scope, savestack=3 61 <> | 4: ANYOF[b] failed... 60 | 4: ANYOF[b] failed... 59 | 4: ANYOF[b] failed... 58 | 4: ANYOF[b] failed... 57 | 4: ANYOF[b] failed... 56 | 4: ANYOF[b] failed... 55 | 4: ANYOF[b] failed... 54 | 4: ANYOF[b] failed... 53 | 4: ANYOF[b] failed... 52 | 4: ANYOF[b] failed... 51 | 4: ANYOF[b] failed... 50 | 4: ANYOF[b] failed... 49 | 4: ANYOF[b] failed... 48 | 4: ANYOF[b] failed... 47 | 4: ANYOF[b] failed... 46 | 4: ANYOF[b] failed... 45 | 4: ANYOF[b] failed... 44 | 4: ANYOF[b] failed... 43 | 4: ANYOF[b] failed... 42 | 4: ANYOF[b] failed... 41 | 4: ANYOF[b] failed... 40 | 4: ANYOF[b] failed... 39 | 4: ANYOF[b] failed... 38 | 4: ANYOF[b] failed... 37 | 4: ANYOF[b] failed... 36 | 4: ANYOF[b] failed... 35 | 4: ANYOF[b] failed... 34 | 4: ANYOF[b] failed... 33 | 4: ANYOF[b] failed... 32 | 4: ANYOF[b] failed... 31 | 4: ANYOF[b] failed... 30 | 4: ANYOF[b] failed... 29 | 4: ANYOF[b] failed... 28 | 4: ANYOF[b] failed... 27 | 4: ANYOF[b] failed... 26 | 4: ANYOF[b] failed... 25 | 4: ANYOF[b] failed... 24 | 4: ANYOF[b] failed... 23 | 4: ANYOF[b] failed... 22 | 4: ANYOF[b] failed... 21 | 4: ANYOF[b] failed... 20 | 4: ANYOF[b] failed... 19 | 4: ANYOF[b] failed... 18 | 4: ANYOF[b] failed... 17 | 4: ANYOF[b] failed... 16 | 4: ANYOF[b] failed... 15 | 4: ANYOF[b] failed... 14 | 4: ANYOF[b] failed... 13 | 4: ANYOF[b] failed... 12 | 4: ANYOF[b] failed... 11 | 4: ANYOF[b] failed... 10 | 4: ANYOF[b] failed... 9 | 4: ANYOF[b] failed... 8 | 4: ANYOF[b] failed... 7 | 4: ANYOF[b] failed... 6 | 4: ANYOF[b] failed... 5 | 4: ANYOF[b] failed... 4 | 4: ANYOF[b] failed... 3 | 4: ANYOF[b] failed... 2 | 4: ANYOF[b] failed... 1 | 4: ANYOF[b] failed... 0 <> | 4: ANYOF[b] failed... failed... Setting an EVAL scope, savestack=3 1 | 1: STAR EXACT can match 60 times out of 2147483647... Setting an EVAL scope, savestack=3 ... # much similar stuff omitted EXACT can match 2 times out of 2147483647... Setting an EVAL scope, savestack=3 61 <> | 4: ANYOF[b] failed... 60 | 4: ANYOF[b] failed... 59 | 4: ANYOF[b] failed... failed... Setting an EVAL scope, savestack=3 60 | 1: STAR EXACT can match 1 times out of 2147483647... Setting an EVAL scope, savestack=3 61 <> | 4: ANYOF[b] failed... 60 | 4: ANYOF[b] failed... failed... Contradicts stclass... Match failed Hello Freeing REx: `"a*[b]"'