2 context reference FILE *
3 oneof rw_none, rw_read, rw_write, rw_either
10 rw_read + rw_write ==> rw_none
11 rw_none + * ==> rw_none
12 rw_either + rw_read ==> rw_read
13 rw_either + rw_write ==> rw_write
14 rw_either + rw_none ==> rw_none
17 rw_read as rw_write ==> error "Must reset file between read and write."
18 rw_write as rw_read ==> error "Must reset file between write and read."
19 rw_none as rw_read ==> error "File in unreadable state."
20 rw_none as rw_write ==> error "File in unwritable state."
22 rw_either as rw_write ==> rw_write
23 rw_either as rw_read ==> rw_read