src/JmesPath/Parser.php
private function parseArrayIndexExpression()
    {
        static $matchNext = [
            T::T_NUMBER   => true,
            T::T_COLON    => true,
            T::T_RBRACKET => true
        ];

        $pos = 0;
        $parts = [null, null, null];
        $expected = $matchNext;

        do {
            if ($this->token['type'] == T::T_COLON) {
                $pos++;
                $expected = $matchNext;
            } elseif ($this->token['type'] == T::T_NUMBER) {
                $parts[$pos] = $this->token['value'];
                $expected = [T::T_COLON => true, T::T_RBRACKET => true];
            }
            $this->next($expected);
        } while ($this->token['type'] != T::T_RBRACKET);

        // Consume the closing bracket
        $this->next();

        if ($pos === 0) {
            // No colons were found so this is a simple index extraction
            return ['type' => 'index', 'value' => $parts[0]];
        }

        if ($pos > 2) {
            throw $this->syntax('Invalid array slice syntax: too many colons');
        }

        // Sliced array from start (e.g., [2:])
        return [
            'type'     => 'projection',
            'from'     => 'array',
            'children' => [
                ['type' => 'slice', 'value' => $parts],
                $this->parseProjection(self::$bp[T::T_STAR])
            ]
        ];
    }
private function parseArrayIndexExpression()
    {
        static $matchNext = [
            T::T_NUMBER   => true,
            T::T_COLON    => true,
            T::T_RBRACKET => true
        ];

        $pos = 0;
        $parts = [null, null, null];
        $expected = $matchNext;

        do {
            if ($this->token['type'] == T::T_COLON) {
                $pos++;
                $expected = $matchNext;
            } elseif ($this->token['type'] == T::T_NUMBER) {
                $parts[$pos] = $this->token['value'];
                $expected = [T::T_COLON => true, T::T_RBRACKET => true];
            }
            $this->next($expected);
        } while ($this->token['type'] != T::T_RBRACKET);

        // Consume the closing bracket
        $this->next();

        if ($pos === 0) {
            // No colons were found so this is a simple index extraction
            return ['type' => 'index', 'value' => $parts[0]];
        }

        if ($pos > 2) {
            throw $this->syntax('Invalid array slice syntax: too many colons');
        }

        // Sliced array from start (e.g., [2:])
        return [
            'type'     => 'projection',
            'from'     => 'array',
            'children' => [
                ['type' => 'slice', 'value' => $parts],
                $this->parseProjection(self::$bp[T::T_STAR])
            ]
        ];
    }
Parses an array index expression (e.g., [0], [1:2:3]