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| author | Adam Scarr <adam@vektah.net> | 2017-08-10 21:04:14 +1000 |
|---|---|---|
| committer | Adam Scarr <adam@vektah.net> | 2017-08-10 21:08:18 +1000 |
| commit | af542eff9e1e51561a9efa37685ee07b1d01b53e (patch) | |
| tree | c700bdca58b4f9bbeb89ba1b102b2a779c88f7f3 /readme.md | |
| parent | b64fcfaa6115eb4a5f65c12d37f95d842136ae35 (diff) | |
Add parse logging
Diffstat (limited to 'readme.md')
| -rw-r--r-- | readme.md | 72 |
1 files changed, 65 insertions, 7 deletions
@@ -1,12 +1,7 @@ goparsify [](https://circleci.com/gh/Vektah/goparsify/tree/master) [](https://godoc.org/github.com/Vektah/goparsify) ========= -A parser-combinator library for building easy to test, read and maintain parsers using functional composition. - -### todo - - fatal errors: Some way for a parser to say "Ive found a good match, the input is broken, stop here with an error" - - better errors: currently only the longest error is returned, but it would be nice to show all expected tokens that could follow. - +A parser-combinator library for building easy to test, read and maintain parsers using functional composition. ### benchmarks I dont have many benchmarks set up yet, but the json parser is very promising. Nearly keeping up with the stdlib for raw speed: @@ -19,7 +14,70 @@ PASS ok github.com/vektah/goparsify/json 10.840s ``` -### debugging mode +### debugging parsers + +When a parser isnt working as you intended you can build with debugging and enable logging to get a detailed log of exactly what the parser is doing. + +1. First build with debug using `-tags debug` +2. enable logging by passing a runtime flag -parselogs or calling `EnableLogging(os.Stdout)` in your code. + +This works great with tests, eg in the goparsify source tree +``` +$ cd html +$ go test -tags debug -parselogs +html.go:50 | <body>hello <p | | tag +html.go:45 | <body>hello <p | | tstart +html.go:45 | body>hello <p c | < | < +html.go:20 | >hello <p color | body | identifier +html.go:35 | >hello <p color | | attrs +html.go:34 | >hello <p color | | attr +html.go:20 | >hello <p color | fail | identifier +html.go:45 | hello <p color= | > | > +html.go:26 | hello <p color= | | elements +html.go:25 | hello <p color= | | element +html.go:21 | <p color="blue" | hello | text +html.go:25 | <p color="blue" | | element +html.go:21 | <p color="blue" | fail | text +html.go:50 | <p color="blue" | | tag +html.go:45 | <p color="blue" | | tstart +html.go:45 | p color="blue"> | < | < +html.go:20 | color="blue">w | p | identifier +html.go:35 | color="blue">w | | attrs +html.go:34 | color="blue">w | | attr +html.go:20 | ="blue">world</ | color | identifier +html.go:34 | "blue">world</p | = | = +html.go:34 | >world</p></bod | | string literal +html.go:34 | >world</p></bod | | attr +html.go:20 | >world</p></bod | fail | identifier +html.go:45 | world</p></body | > | > +html.go:26 | world</p></body | | elements +html.go:25 | world</p></body | | element +html.go:21 | </p></body> | world | text +html.go:25 | </p></body> | | element +html.go:21 | </p></body> | fail | text +html.go:50 | </p></body> | | tag +html.go:45 | </p></body> | | tstart +html.go:45 | /p></body> | < | < +html.go:20 | /p></body> | fail | identifier +html.go:46 | </p></body> | | tend +html.go:46 | p></body> | </ | </ +html.go:20 | ></body> | p | identifier +html.go:46 | </body> | > | > +html.go:25 | </body> | | element +html.go:21 | </body> | fail | text +html.go:50 | </body> | | tag +html.go:45 | </body> | | tstart +html.go:45 | /body> | < | < +html.go:20 | /body> | fail | identifier +html.go:46 | </body> | | tend +html.go:46 | body> | </ | </ +html.go:20 | > | body | identifier +html.go:46 | | > | > +PASS +ok github.com/vektah/goparsify/html 0.118s +``` + +### debugging performance If you build the parser with -tags debug it will instrument each parser and a call to DumpDebugStats() will show stats: ``` Any() 415.7136ms 87000 calls json.go:35 |