:=
cbind | is NAME
cbind | epsilon
This attribute is used to specify the precedence of a C expression
so that the code generator can place parenthesis around it if it
is embedded in a context with higher precedence.
Felix automatically calculates the predence for tightly
packed encodings of all C operators; for example there is no
need to specify the precedence of "$1+$2".
Otherwise, if the precedence is omitted, the expression is
assumed to be low, and parenthesis is always added.
The precedence must be one of the following identifiers:
- atom
- primary
- postfix
- unary
- cast
- pm
- mult
- add
- shift
- rel
- eq
- band
- bxor
- bor
- and
- xor
- or
- cond
- assign
- comma
- expr