lark

lark copied to clipboard

`%ignore` is the last domino before grammar composition is fully supported in Lark. We should be able to support it in both LALR and Earley. Robust grammar composition would be...

erezsh

Unexpected behavior of rule priority.

2

Hi, I've noticed an unexpected behaviour of rule priority in the default parser `"earley"`. I'm going to describe how to reproduce the issue step-by-step, by implementing a simple propositional calculus...

marcofavorito

Add EOF symbol to match end of input

17

Can be signified with `$` Must be optional (grammars don't have to contain it to be correct) Need to make sure it works for both LALR and Earley, and with...

erezsh

Better token formatting available?

5

**What is your question?** I have a Lark grammar that has the following production: ``` !inneroperator : "has" | "=" | "" | "=" | "!=" ``` (The whole grammar...

pmiddend

Terminals cannot be transformed in tree-less LALR?

5

**Describe the bug** I've written a transformer with the line `DECIMAL = float` (from `%import common.DECIMAL` in the grammar) and it seemed to work fine post-transforming an Earley-parsed tree –...

qwertystop

HTML documentation is not built reproducibly (Sphinx)

10

The present sphinx configuration leads to sources being included in the html build inside the `_sources` directory (because `html_copy_source` is set to `true` by default). Inside this directory the file...

wiene

Lalr parser raises UnexpectedToken('$END', ...) rather than UnexpectedEOF

3

**Describe the bug** When an input is exhausted, the earley parser raises `lark.errors.UnexpectedEOF(...)`, while the lalr parser raises `lark.errors.UnexpectedToken('$END', ...)`. For consistency sake, in lalr parsers, if the error raised...

zevisert

Supplying a custom lexer is hard because of "assert issubclass"

2

**Suggestion** My use case is a bit odd: I'm not parsing text, I'm parsing rows in a database. Background: my employer provides network services to businesses (e.g. Internet access, dark...

gward

Trees are always simpler to work with than state-machines.

4

Hey, it looks very interesting! You make this statement 2 times: "Trees are always simpler to work with than state-machines." Could you back this up with some resource or examples?...

kootenpv

Can you have a Transformer or lexer_callback that replaces the output of one rule with multiple values?

24

**What is your question?** Try to be accurate and concise. **If you're having trouble with your code or grammar** Provide a small script that encapsulates your issue. Explain what you're...

rfox12-edu