error compiling valid calc expression

[heyymarco]

this css/scss syntax below is valid when compiled using css preprocessor like sass, but postcss-calc thinks it's wrong:

.btn {
    --test: calc(
        1
        * clamp(
            1 ,
            ((1 * 1) * 1) ,
            1
        )
    );
}

error:
JisonLexerError: Lexical error on line 4: Unrecognized text.

  Erroneous area:
1: 1
2:         * clamp(
3:             1 ,
4:             ((1 * 1) * 1) ,
^............................^
5:             1
6:         )