703 Commits (da57118a43a904f753d44d407994cf0b36358adc)
 

Author SHA1 Message Date
David Majda da57118a43 Implement basic support for tracing
Parsers can now be generated with support for tracing using the --trace
CLI option or a boolean |trace| option to |PEG.buildParser|. This makes
them trace their progress, which can be useful for debugging. Parsers
generated with tracing support are called "tracing parsers".

When a tracing parser executes, by default it traces the rules it enters
and exits by writing messages to the console. For example, a parser
built from this grammar:

  start = a / b
  a = "a"
  b = "b"

will write this to the console when parsing input "b":

  1:1 rule.enter start
  1:1 rule.enter   a
  1:1 rule.fail    a
  1:1 rule.enter   b
  1:2 rule.match   b
  1:2 rule.match start

You can customize tracing by passing a custom *tracer* to parser's
|parse| method using the |tracer| option:

  parser.parse(input, { trace: tracer });

This will replace the built-in default tracer (which writes to the
console) by the tracer you supplied.

The tracer must be an object with a |trace| method. This method is
called each time a tracing event happens. It takes one argument which is
an object describing the tracing event.

Currently, three events are supported:

  * rule.enter -- triggered when a rule is entered
  * rule.match -- triggered when a rule matches successfully
  * rule.fail  -- triggered when a rule fails to match

These events are triggered in nested pairs -- for each rule.enter event
there is a matching rule.match or rule.fail event.

The event object passed as an argument to |trace| contains these
properties:

  * type   -- event type
  * rule   -- name of the rule the event is related to
  * offset -- parse position at the time of the event
  * line   -- line at the time of the event
  * column -- column at the time of the event
  * result -- rule's match result (only for rule.match event)

The whole tracing API is somewhat experimental (which is why it isn't
documented properly yet) and I expect it will evolve over time as
experience is gained.

The default tracer is also somewhat bare-bones. I hope that PEG.js user
community will develop more sophisticated tracers over time and I'll be
able to integrate their best ideas into the default tracer.
9 years ago
David Majda 675561f085 Rename and generalize |generateCache{Header,Footer}|
Rename |generateCache{Header,Footer}| to |generateRule{Header,Footer}|
and change their responsibility to generate overall header/footer of a
rule function (when optimizing for speed) or the |peg$parseRule|
function (when optimizing for speed). This creates a natural place where
to generate tracing code (coming soon).
9 years ago
David Majda fb5f6c6ee9 Make labels behave like block-scoped variables
Action and predicate code can now see variables defined in expressions
"above" them.

Based on a pull request by Bryon Vandiver (@asterick):

  https://github.com/pegjs/pegjs/pull/180

Fixes #316.
9 years ago
David Majda 73795a65cc Behavior specs cleanup: Add group specs
While groups don't create separate nodes on the AST level, they exist
as concept on the user level, so they should be specified.
9 years ago
David Majda e306b58443 Behavior specs cleanup: Improve error reporting specs 9 years ago
David Majda e9d038547d Behavior specs cleanup: Improve semantic predicate specs
Note that use of |text| inside semantic predicate code is no longer
tested and officially supported.
9 years ago
David Majda 3d9600b81b Behavior specs cleanup: Improve action specs 9 years ago
David Majda b623396cb8 Behavior specs cleanup: Improve initializer specs
Note that use of |text|, |offset|, |line|, and |column| inside
initializer code is no longer tested and officially supported.
9 years ago
David Majda fee58d0806 Behavior specs cleanup: Improve rule specs 9 years ago
David Majda fa70e70ddf Behavior specs cleanup: Improve choice specs 9 years ago
David Majda b3828919e2 Behavior specs cleanup: Improve sequence specs 9 years ago
David Majda 548209b48b Behavior specs cleanup: Improve simple predicate specs 9 years ago
David Majda 52144e48cb Behavior specs cleanup: Improve label specs 9 years ago
David Majda c5c44b9d0c Behavior specs cleanup: Improve text specs 9 years ago
David Majda bb708490a0 Behavior specs cleanup: Improve one or more specs 9 years ago
David Majda b9a3b44cf2 Behavior specs cleanup: Improve zero or more specs 9 years ago
David Majda c377eff876 Behavior specs cleanup: Improve optional specs 9 years ago
David Majda ade2c249f2 Behavior specs cleanup: Improve rule reference specs 9 years ago
David Majda 936d6453a5 Behavior specs cleanup: Improve dot specs 9 years ago
David Majda 74be12c657 Behavior specs cleanup: Improve character class specs 9 years ago
David Majda 54191fbf12 Behavior specs cleanup: Improve literal specs 9 years ago
David Majda 2faff0000e Behavior specs cleanup: Make |toParse| work without expected value
This means we can assert just "this string parses" and ignore the
returned value.
9 years ago
David Majda ce91921a1d Behavior specs cleanup: Don't describe named rules separately
While naming a rule creates a separate node on the AST level, it's not a
new concept on the user level, so its specs should be a part of rule
specs.
9 years ago
David Majda a597e65a66 Behavior specs cleanup: Reorder toplevel |describe| blocks
Reorder toplevel |describe| blocks to more closely match ordering used
in the PEG.js grammar and elsewhere in PEG.js.
9 years ago
David Majda 3308807d22 Behavior specs cleanup: Move spec/api/generated-parser-behavior.spec.js
Move spec/api/generated-parser-behavior.spec.js to
spec/behavior/generated-parser-behavior.spec.js. It's not an API test,
strictly speaking.
9 years ago
David Majda 84473db3ce Specs cleanup: Small description cleanups/fixes 9 years ago
David Majda cc8edd8892 README.md: Fix typo
Based on a pull request by Julien Valéry:

  https://github.com/pegjs/website/pull/14
9 years ago
David Majda fb7de36051 Update website URL
PEG.js website was moved from http://pegjs.majda.cz/ to http://pegjs.org/.
9 years ago
David Majda 2dedce52d6 Add info about the Bower package maintainer 9 years ago
David Majda 9a822528f9 Add Bower installation instructions 9 years ago
David Majda 178d56699a Update GitHub project URLs
See https://groups.google.com/d/msg/pegjs/4a6zWKQSG6U/n8Pm257Lz6wJ.

I didn't update CHANGELOG.md as I consider issue URLs there historical artifacts
;-)
9 years ago
David Majda 5a2ca2abc7 Add two missing blank lines 10 years ago
David Majda 5ce5f7a612 Specs cleanup: Use raw node types in |generateBytecode| specs
Use raw node types instead of humanized node names in |generateBytecode|
specs. This corresponds more closely to the level the specs are written
at.
10 years ago
David Majda 0977dd37a3 Reordering in visitors and their specs
Reorder visiting functions and their specs to more closely match
ordering used in the PEG.js grammar.
10 years ago
David Majda 850ddf5889 Specs cleanup: Simplify compiler passes specs
After 898a7b5a2d the specs mostly tested
the visitor implementation, not actual code in the passes.
10 years ago
David Majda 4ec9e6ba10 Remove useless test in the |reportLeftRecursion| pass
Empty sequences are not allowed anymore so we don't have to test for
them.
10 years ago
David Majda 898a7b5a2d Simplify visitors by providing default visit functions
The |visitor.build| function now supplies default visit functions for
visitors it builds. These functions don't do anything beside traversing
the tree and passing arguments around to child visit functions.

Having the default visit functions allowed to simplify several visitors.
10 years ago
David Majda 4a3b9cbb8d Require Node.js >= 0.10.0
Travis CI builds with Node.js 0.8.x started to fail:

  https://travis-ci.org/dmajda/pegjs/jobs/26691570

Rather than investigating what's wrong I decided to stop supporting Node
0.8.x. Node.js 0.10.x is here for over a year, which should be enough
time for everyone to upgrade in the fast-paced Node.js world.
10 years ago
David Majda e101e1b6f3 Specs cleanup: Implement generated parser API specs
The generated parser API specs are mostly extracted from
generated-parser.spec.js, which got renamed to
generated-parser-behavior.spec.js to better reflect its purpose.
10 years ago
David Majda 94c8b08acf Specs cleanup: Implement plugin API specs 10 years ago
David Majda d0ff834a3d Specs cleanup: Implement PEG.js API specs
Some parts were previously part of generated parser specs, these were
moved.
10 years ago
David Majda 0306a76152 Specs cleanup: Rename & simplify |varyAll|
Rename |varyAll| to |varyOptimizationOptions|, because that's what the
function does. Simplify as we don't need a fully generic solution.
10 years ago
David Majda 3d637173ee Specs cleanup: Split specs into unit and API specs
Unit specs are unit tests of internal stuff. API specs are tests of the
user-visible APIs and behavior.

I think it makes sense to make this distinction because then the public
API line is more clearly visible e.g. when using the specs as
documentation.
10 years ago
David Majda f457c41dd4 Declare the |j| variable before use in lib/utils/arrays.js
Until now it was inadvertently global.
10 years ago
David Majda 24394e3f91 Fix comment alignment in lib/compiler/passes/generate-javascript.js 10 years ago
David Majda 2b06476c69 Regenerate lib/parser.js after bytecode changes 10 years ago
David Majda dad1207c46 Improve semantics of the TEXT bytecode instruction
The TEXT instruction now replaces position at the top of the stack with
the input from that position until the current position. This is simpler
and cleaner semantics than the previous one, where TEXT also popped an
additional value from the stack and kept the position there.
10 years ago
David Majda a815a8b902 Implement additional PUSH_* bytecode instructions
Implement the following bytecode instructions:

  * PUSH_UNDEFINED
  * PUSH_NULL
  * PUSH_FAILED
  * PUSH_EMPTY_ARRAY

These instructions push simple JavaSccript values to the stack directly,
without going through constants. This makes the bytecode slightly
shorter and the bytecode generator somewhat simpler.

Also note that PUSH_EMPTY_ARRAY allows us to avoid a hack which protects
the [] constant from modification.
10 years ago
David Majda c6f0818d49 Use sentence case consistently in {spec,benchmark}/README.md headers 10 years ago
David Majda 4d456402be Small cleanup of benchmark/index.js
Update coding style to match the rest of PEG.js.
10 years ago