diff options
| author | hallgren <hallgren@chalmers.se> | 2013-02-27 20:59:43 +0000 |
|---|---|---|
| committer | hallgren <hallgren@chalmers.se> | 2013-02-27 20:59:43 +0000 |
| commit | 0feb386691bb82e13c3dcc01e27ae33d8865f2ca (patch) | |
| tree | f117b97d05861b5dcf58a241c8c2f6547b32182e /src/compiler/GF/Grammar/Printer.hs | |
| parent | 95c4cbb8f5ef10d04839e73a7f0dafe8536dab2d (diff) | |
Faster regular expression pattern matching in the grammar compiler.
The sequence operator (x+y) was implemented by splitting the string to be
matched at all positions and trying to match the parts against the two
subpatterns. To reduce the number of splits, we now estimate the minimum and
maximum length of the string that the subpatterns could match. For common
cases, where one of the subpatterns is a string of known length, like
in (x+"y") or (x + ("a"|"o"|"u"|"e")+"y"), only one split will be tried.
Diffstat (limited to 'src/compiler/GF/Grammar/Printer.hs')
| -rw-r--r-- | src/compiler/GF/Grammar/Printer.hs | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/src/compiler/GF/Grammar/Printer.hs b/src/compiler/GF/Grammar/Printer.hs index 276f2c9c2..0d9d41b7b 100644 --- a/src/compiler/GF/Grammar/Printer.hs +++ b/src/compiler/GF/Grammar/Printer.hs @@ -238,6 +238,7 @@ ppCase q (p,e) = ppPatt q 0 p <+> text "=>" <+> ppTerm q 0 e ppPatt q d (PAlt p1 p2) = prec d 0 (ppPatt q 0 p1 <+> char '|' <+> ppPatt q 1 p2)
ppPatt q d (PSeq p1 p2) = prec d 0 (ppPatt q 0 p1 <+> char '+' <+> ppPatt q 1 p2)
+ppPatt q d (PMSeq (_,p1) (_,p2)) = prec d 0 (ppPatt q 0 p1 <+> char '+' <+> ppPatt q 1 p2)
ppPatt q d (PC f ps) = if null ps
then ppIdent f
else prec d 1 (ppIdent f <+> hsep (map (ppPatt q 3) ps))
|