Parse ABNF grammars
For more information on the flavor of ABNF (Augmented Backus-Naur Form) supported by this project, see RFC 5234 and RFC 7405.
Installation:
npm install -g abnf
Example:
import { parseFile } from "abnf";
const rules = await parseFile("myfile.abnf");
CLI
There are a few binaries included:
abnf_check
Check the given ABNF file for correctness.
abnf_ast
Output the generated abstract syntax tree for the ABNF input. This output is mostly diagnostic in nature, not really meant to be parsed.
abnf_gen
Generate a Peggy grammar from the ABNF. The idea is that you could then annotate this grammar with actions in order to create a useful parser.
abnf_test
Using an ABNF, test inputs to see if they match. Returns the Peggy parse tree, which will likely be somewhat confusing until you're familiar with Peggy.
Workflow
$ cat << EOF > foo.abnf
f = "abc"
EOF
$ abnf_gen foo.abnf
$ cat foo.peggy
f
= "abc"i
$ abnf_test foo.abnf -t abc
'abc'
$ abnf_test foo.peggy -t ab
Error: Expected "abc" but "a" found.
--> command line:1:1
|
1 | ab
| ^
API
.parseFile(input)
Parse the file with the given name, returning a promise for a Rules object.
.parseString(input, grammarSource = "unknown")
Parse the given string and return a Rules object. The grammarSource
is
the name of the file that the input came from.
.parseStream(stream, grammarSource = "stdin")
Read the stream, parse it, and return a promise for a Rules object. The
grammarSource
is the name of the file that the input came from.
Returned Rules object shape
Rules.first
The name of the first rule in the input grammar.
Rules.defs
A hash of Rule objects indexed by uppercase rulename.
Rules.refs
An array of RuleRef objects.
Rule.name
The name of the rule
Rule.loc
The Peggy location in the input file where the rule name was defined
Rule.def
The definition of the rule. More information forthcoming.
RuleRef.name
The name of the rule that was referenced
RuleRef.loc
The Peggy location in the input file where the rule name was referenced.