The type of a sequence of messages.
Make a sequence of messages from a single message.
If f
is defined at t
apply it and return the resulting sequence
of messages.
If f
is defined at t
apply it and return the resulting sequence
of messages. Otherwise, return an empty sequence.
Check that the entity e
is used legally and return appropriate
messages if not.
Check that the entity e
is used legally and return appropriate
messages if not. If the entity is an error entity (unknown or multiply
defined, keep silent on the grounds that the error has already been
reported elsewhere (e.g., at the declaration site of the entity).
Otherwise, if f
is defined at e
return the messages that f (e)
evaluates to. If f
is not defined at e
, keep silent.
If cond
is true make a singleton message list that associates the
message msg
with the start position recorded for value
(if any).
If cond
is true make a singleton message list that associates the
message msg
with the start position recorded for value
(if any).
cond
can be omitted and defaults to true. Any finish
position
that is recorded for value
is ignored at present.
A value representing no messages.
Output the messages in order of position using the given emitter, which defaults to standard error.
Sort the messages by increasing position.
Facility for building messages associated with positioned values.