PostgreSql parser can't parse function and procedure's body

[victor-wiki]

I tried to parse the PostgreSQL using the c# code generated by PostgreSQLLexer.g4 and PostgreSQLParser.g4, but I found that the body of function and procedure always be parsed as AnysconstContext, no details. I don't know why it can't be parsed as similar to other parsers (TSQL, PLSQL and MySQL). They are at least having some common points, such as the select, insert, update and delete clauses.