Calling the parsing function could have been done without the ugly table
using |eval|, but this seemed to degrade performance significantly (by
about 3 %). This is probably because engines optimize badly in presence
of |eval|.
The method used in this patch does not change the benchmark suite
execution speed statistically significantly on V8.
Detailed results (benchmark suite totals):
---------------------------------
Test # Before After
---------------------------------
1 38.24 kB/s 38.28 kB/s
2 38.35 kB/s 38.15 kB/s
3 38.43 kB/s 38.40 kB/s
4 38.53 kB/s 38.20 kB/s
5 38.25 kB/s 38.39 kB/s
---------------------------------
Average 38.36 kB/s 38.39 kB/s
---------------------------------
Mozilla/5.0 (X11; U; Linux i686; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.151 Safari/534.1
This patch prevents portability problems. In particular, it fixes a
problem where "SyntaxError: Invalid range in character class." error
appeared when using command-line version on Widnows (see GH-13).
Before this commit, uniqueness was checked when addding the failure. Now
we make the entiries unique when generating the error report, saving a
little time when the parsing is successful. This does not increase the
benchmark numbers too much though.
Results of benchmark with 100 runs on V8:
Before: 37.25 kB/s
After: 37.41 kB/s
Speedup: 0.241 %
Mozilla/5.0 (X11; U; Linux i686; en-US) AppleWebKit/534.3 (KHTML, like
Gecko) Chrome/6.0.472.63 Safari/534.3
This is a small win performance-wise.
Results of benchmark with 100 runs on V8:
Before: 31.65 kB/s
After: 32.83 kB/s
Speedup: 3.728 %
Mozilla/5.0 (X11; U; Linux i686; en-US) AppleWebKit/533.4 (KHTML, like
Gecko) Chrome/5.0.375.127 Safari/533.4
Passing the context is not necessary, global variable is good enough
(passing the context would make more sense if each AST node was
translated into a function call, but this isn't the case).
The performance gain is very small, on the border of statstical error.
Results of benchmark with 100 runs on V8:
Before: 31.49 kB/s
After: 31.57 kB/s
Speedup: 0.254 %
Mozilla/5.0 (X11; U; Linux i686; en-US) AppleWebKit/533.4 (KHTML, like
Gecko) Chrome/5.0.375.127 Safari/533.4
The source code is now in the src directory. The library needs to be
built using "rake", which creates the lib/peg.js file by combining the
source files.
David Majda