This repository contains a scanner/parser for Rego, the policy language from OPA.
I work on this in my spare time, so progress is slow.
%% Integrating OPA
Rest API
Dus als je een policy hebt
package example.authz
default allow := false
allow {
...Dan gebruik je de api als volgt
POST /v1/data/example/authz/allow
...
%% Inspiration
https://www.openpolicyagent.org/docs/latest/policy-reference/#grammar
Grammar https://github.com/antlr/grammars-v4/tree/rego
module = package { import } policy
package = "package" ref
import = "import" ref [ "as" var ]
policy = { rule }
rule = [ "default" ] rule-head { rule-body }
rule-head = var [ "(" rule-args ")" ] [ "[" term "]" ] [ = term ]
rule-args = term { "," term }
rule-body = [ else [ = term ] ] "{" query "}"
query = literal { ";" | [\r\n] literal }
literal = ( some-decl | expr | "not" expr ) { with-modifier }
with-modifier = "with" term "as" term
some-decl = "some" var { "," var }
expr = term | expr-built-in | expr-infix
expr-built-in = var [ "." var ] "(" [ term { , term } ] ")"
expr-infix = [ term "=" ] term infix-operator term
term = ref | var | scalar | array | object | set | array-compr | object-compr | set-compr
array-compr = "[" term "|" rule-body "]"
set-compr = "{" term "|" rule-body "}"
object-compr = "{" object-item "|" rule-body "}"
infix-operator = bool-operator | arith-operator | bin-operator
bool-operator = "=" | "!=" | "<" | ">" | ">=" | "<="
arith-operator = "+" | "-" | "*" | "/"
bin-operator = "&" | "|"
ref = var { ref-arg }
ref-arg = ref-arg-dot | ref-arg-brack
ref-arg-brack = "[" ( scalar | var | array | object | set | "_" ) "]"
ref-arg-dot = "." var
var = ( ALPHA | "_" ) { ALPHA | DIGIT | "_" }
scalar = string | NUMBER | TRUE | FALSE | NULL
string = STRING | raw-string
raw-string = "`" { CHAR-"`" } "`"
array = "[" term { "," term } "]"
object = "{" object-item { "," object-item } "}"
object-item = ( scalar | ref | var ) ":" term
set = empty-set | non-empty-set
non-empty-set = "{" term { "," term } "}"
empty-set = "set(" ")"
====
[] optional (zero or one instances)
{} repetition (zero or more instances)
| alternation (one of the instances)
() grouping (order of expansion)
STRING JSON string
NUMBER JSON number
TRUE JSON true
FALSE JSON false
NULL JSON null
CHAR Unicode character
ALPHA ASCII characters A-Z and a-z
DIGIT ASCII characters 0-9
CR Carriage Return
LF Line Feed