[sv-bc] questions about property/sequence precedence

I have some questions about the precedence of operators in the
property and sequence grammars. Tables 17.1 and 17.2 give the
precedence and associativity for some operators, but not all.
Also, the grammar is ambiguous.

Table 17.1 lists the precedences for the following sequence operators:

    [* [- [=>
    ##
    throughput
    within
    intersect
    and
    or

It doesn't give a precedence or associativity for clocking_event. The
grammar allows, for instance:

    @clk seq and seq

Is this to be parsed as:

    @clk (seq and seq)

or

    (@clk seq) and seq

Table 17.2 lists the precedences for the following property operators:

    not
    and
    or
    if .. else
    |-> |=>

It also doesn't give a precedence for clocking_event.

The grammar is also ambiguous in that it doesn't distinguish some
sequences from properties:

    expr and expr

Is this a sequence consisting of two expressions, a property consisting
of two expressions, or a property consisting of two sequences?

Paul
Received on Fri Oct 8 18:50:54 2004