Method parse

parser/parser.go:333–373

(expr runes.Buffer, desc string)

var _ gen.CELVisitor = (*parser)(nil)

func (p *parser) parse(expr runes.Buffer, desc string) ast.Expr {
	lexer := gen.NewCELLexer(newCharStream(expr, desc))
	lexer.RemoveErrorListeners()
	lexer.AddErrorListener(p)

	prsr := gen.NewCELParser(antlr.NewCommonTokenStream(lexer, 0))
	prsr.RemoveErrorListeners()

	prsrListener := &recursionListener{
		maxDepth:      p.maxRecursionDepth,
		ruleTypeDepth: map[int]*int{},
	}

	prsr.AddErrorListener(p)
	prsr.AddParseListener(prsrListener)

	prsr.SetErrorHandler(&recoveryLimitErrorStrategy{
		DefaultErrorStrategy:             antlr.NewDefaultErrorStrategy(),
		errorRecoveryLimit:               p.errorRecoveryLimit,
		errorRecoveryTokenLookaheadLimit: p.errorRecoveryLookaheadTokenLimit,
	})

	defer func() {
		if val := recover(); val != nil {
			switch err := val.(type) {
			case *lookaheadLimitError:
				p.errors.internalError(err.Error())
			case *recursionError:
				p.errors.internalError(err.Error())
			case *tooManyErrors:
				// do nothing
			case *recoveryLimitError:
				// do nothing, listeners already notified and error reported.
			default:
				panic(val)
			}
		}
	}()

	return p.Visit(prsr.Start_()).(ast.Expr)
}

// Visitor implementations.
func (p *parser) Visit(tree antlr.ParseTree) any {