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Diffstat (limited to 'textproc/re_graph/pkg-descr')
| -rw-r--r-- | textproc/re_graph/pkg-descr | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/textproc/re_graph/pkg-descr b/textproc/re_graph/pkg-descr new file mode 100644 index 000000000000..9b9901414afd --- /dev/null +++ b/textproc/re_graph/pkg-descr @@ -0,0 +1,17 @@ +The re_graph.pl program graphs regular expressions. The guts of the regular +expression engine is a simple state machine. The various states and operations +in the regular expression parser can be displayed using a surprisingly simple +diagram. + +A few notes on what you are looking at: + * The nodes Start and Stop denote the beginning and end of the regular + expression. + * The solid squares denote atoms. Lines indicate the next state. When a + line splits, the state machine will take the top line first. If it's + path is blocked it will backup and take the next lower line. This is + repeated until it finds a path to the end or all paths are exhausted. + * Brown boxes indicate a grouping operation, i.e. (). + * Green boxes indicate a zero with test. The state machine will perform the + test inside the box before moving ahead. + +WWW: http://www.oualline.com/sw/ |