95 lines
3.5 KiB
Ruby
95 lines
3.5 KiB
Ruby
|
module Parslet
|
||
|
|
module ErrorReporter
|
||
|
|
# Instead of reporting the latest error that happens like {Tree} does,
|
||
|
|
# this class reports the deepest error. Depth is defined here as how
|
||
|
|
# advanced into the input an error happens. The errors close to the
|
||
|
|
# greatest depth tend to be more relevant to the end user, since they
|
||
|
|
# specify what could be done to make them go away.
|
||
|
|
#
|
||
|
|
# More specifically, errors produced by this reporter won't be related to
|
||
|
|
# the structure of the grammar at all. The positions of the errors will
|
||
|
|
# be advanced and convey at every grammar level what the deepest rule
|
||
|
|
# was to fail.
|
||
|
|
#
|
||
|
|
class Deepest
|
||
|
|
def initialize
|
||
|
|
@deepest_cause = nil
|
||
|
|
end
|
||
|
|
|
||
|
|
# Produces an error cause that combines the message at the current level
|
||
|
|
# with the errors that happened at a level below (children).
|
||
|
|
#
|
||
|
|
# @param atom [Parslet::Atoms::Base] parslet that failed
|
||
|
|
# @param source [Source] Source that we're using for this parse. (line
|
||
|
|
# number information...)
|
||
|
|
# @param message [String, Array] Error message at this level.
|
||
|
|
# @param children [Array] A list of errors from a deeper level (or nil).
|
||
|
|
# @return [Cause] An error tree combining children with message.
|
||
|
|
#
|
||
|
|
def err(atom, source, message, children=nil)
|
||
|
|
position = source.pos
|
||
|
|
cause = Cause.format(source, position, message, children)
|
||
|
|
return deepest(cause)
|
||
|
|
end
|
||
|
|
|
||
|
|
# Produces an error cause that combines the message at the current level
|
||
|
|
# with the errors that happened at a level below (children).
|
||
|
|
#
|
||
|
|
# @param atom [Parslet::Atoms::Base] parslet that failed
|
||
|
|
# @param source [Source] Source that we're using for this parse. (line
|
||
|
|
# number information...)
|
||
|
|
# @param message [String, Array] Error message at this level.
|
||
|
|
# @param pos [Fixnum] The real position of the error.
|
||
|
|
# @param children [Array] A list of errors from a deeper level (or nil).
|
||
|
|
# @return [Cause] An error tree combining children with message.
|
||
|
|
#
|
||
|
|
def err_at(atom, source, message, pos, children=nil)
|
||
|
|
position = pos
|
||
|
|
cause = Cause.format(source, position, message, children)
|
||
|
|
return deepest(cause)
|
||
|
|
end
|
||
|
|
|
||
|
|
# Returns the cause that is currently deepest. Mainly for specs.
|
||
|
|
#
|
||
|
|
attr_reader :deepest_cause
|
||
|
|
|
||
|
|
# Checks to see if the lineage of the cause given includes a cause with
|
||
|
|
# an error position deeper than the current deepest cause stored. If
|
||
|
|
# yes, it passes the cause through to the caller. If no, it returns the
|
||
|
|
# current deepest error that was saved as a reference.
|
||
|
|
#
|
||
|
|
def deepest(cause)
|
||
|
|
rank, leaf = deepest_child(cause)
|
||
|
|
|
||
|
|
if !deepest_cause || leaf.pos >= deepest_cause.pos
|
||
|
|
# This error reaches deeper into the input, save it as reference.
|
||
|
|
@deepest_cause = leaf
|
||
|
|
return cause
|
||
|
|
end
|
||
|
|
|
||
|
|
return deepest_cause
|
||
|
|
end
|
||
|
|
|
||
|
|
private
|
||
|
|
# Returns the leaf from a given error tree with the biggest rank.
|
||
|
|
#
|
||
|
|
def deepest_child(cause, rank=0)
|
||
|
|
max_child = cause
|
||
|
|
max_rank = rank
|
||
|
|
|
||
|
|
if cause.children && !cause.children.empty?
|
||
|
|
cause.children.each do |child|
|
||
|
|
c_rank, c_cause = deepest_child(child, rank+1)
|
||
|
|
|
||
|
|
if c_rank > max_rank
|
||
|
|
max_rank = c_rank
|
||
|
|
max_child = c_cause
|
||
|
|
end
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
return max_rank, max_child
|
||
|
|
end
|
||
|
|
end
|
||
|
|
end
|
||
|
|
end
|