Current File : //opt/alt/ruby32/share/ruby/syntax_suggest/capture_code_context.rb
# frozen_string_literal: true
module SyntaxSuggest
module Capture
end
end
require_relative "capture/falling_indent_lines"
require_relative "capture/before_after_keyword_ends"
module SyntaxSuggest
# Turns a "invalid block(s)" into useful context
#
# There are three main phases in the algorithm:
#
# 1. Sanitize/format input source
# 2. Search for invalid blocks
# 3. Format invalid blocks into something meaninful
#
# This class handles the third part.
#
# The algorithm is very good at capturing all of a syntax
# error in a single block in number 2, however the results
# can contain ambiguities. Humans are good at pattern matching
# and filtering and can mentally remove extraneous data, but
# they can't add extra data that's not present.
#
# In the case of known ambiguious cases, this class adds context
# back to the ambiguitiy so the programmer has full information.
#
# Beyond handling these ambiguities, it also captures surrounding
# code context information:
#
# puts block.to_s # => "def bark"
#
# context = CaptureCodeContext.new(
# blocks: block,
# code_lines: code_lines
# )
#
# lines = context.call.map(&:original)
# puts lines.join
# # =>
# class Dog
# def bark
# end
#
class CaptureCodeContext
attr_reader :code_lines
def initialize(blocks:, code_lines:)
@blocks = Array(blocks)
@code_lines = code_lines
@visible_lines = @blocks.map(&:visible_lines).flatten
@lines_to_output = @visible_lines.dup
end
def call
@blocks.each do |block|
capture_first_kw_end_same_indent(block)
capture_last_end_same_indent(block)
capture_before_after_kws(block)
capture_falling_indent(block)
end
sorted_lines
end
def sorted_lines
@lines_to_output.select!(&:not_empty?)
@lines_to_output.uniq!
@lines_to_output.sort!
@lines_to_output
end
# Shows the context around code provided by "falling" indentation
#
# Converts:
#
# it "foo" do
#
# into:
#
# class OH
# def hello
# it "foo" do
# end
# end
#
def capture_falling_indent(block)
Capture::FallingIndentLines.new(
block: block,
code_lines: @code_lines
).call do |line|
@lines_to_output << line
end
end
# Shows surrounding kw/end pairs
#
# The purpose of showing these extra pairs is due to cases
# of ambiguity when only one visible line is matched.
#
# For example:
#
# 1 class Dog
# 2 def bark
# 4 def eat
# 5 end
# 6 end
#
# In this case either line 2 could be missing an `end` or
# line 4 was an extra line added by mistake (it happens).
#
# When we detect the above problem it shows the issue
# as only being on line 2
#
# 2 def bark
#
# Showing "neighbor" keyword pairs gives extra context:
#
# 2 def bark
# 4 def eat
# 5 end
#
def capture_before_after_kws(block)
return unless block.visible_lines.count == 1
around_lines = Capture::BeforeAfterKeywordEnds.new(
code_lines: @code_lines,
block: block
).call
around_lines -= block.lines
@lines_to_output.concat(around_lines)
end
# When there is an invalid block with a keyword
# missing an end right before another end,
# it is unclear where which keyword is missing the
# end
#
# Take this example:
#
# class Dog # 1
# def bark # 2
# puts "woof" # 3
# end # 4
#
# However due to https://github.com/ruby/syntax_suggest/issues/32
# the problem line will be identified as:
#
# > class Dog # 1
#
# Because lines 2, 3, and 4 are technically valid code and are expanded
# first, deemed valid, and hidden. We need to un-hide the matching end
# line 4. Also work backwards and if there's a mis-matched keyword, show it
# too
def capture_last_end_same_indent(block)
return if block.visible_lines.length != 1
return unless block.visible_lines.first.is_kw?
visible_line = block.visible_lines.first
lines = @code_lines[visible_line.index..block.lines.last.index]
# Find first end with same indent
# (this would return line 4)
#
# end # 4
matching_end = lines.detect { |line| line.indent == block.current_indent && line.is_end? }
return unless matching_end
@lines_to_output << matching_end
# Work backwards from the end to
# see if there are mis-matched
# keyword/end pairs
#
# Return the first mis-matched keyword
# this would find line 2
#
# def bark # 2
# puts "woof" # 3
# end # 4
end_count = 0
kw_count = 0
kw_line = @code_lines[visible_line.index..matching_end.index].reverse.detect do |line|
end_count += 1 if line.is_end?
kw_count += 1 if line.is_kw?
!kw_count.zero? && kw_count >= end_count
end
return unless kw_line
@lines_to_output << kw_line
end
# The logical inverse of `capture_last_end_same_indent`
#
# When there is an invalid block with an `end`
# missing a keyword right after another `end`,
# it is unclear where which end is missing the
# keyword.
#
# Take this example:
#
# class Dog # 1
# puts "woof" # 2
# end # 3
# end # 4
#
# the problem line will be identified as:
#
# > end # 4
#
# This happens because lines 1, 2, and 3 are technically valid code and are expanded
# first, deemed valid, and hidden. We need to un-hide the matching keyword on
# line 1. Also work backwards and if there's a mis-matched end, show it
# too
def capture_first_kw_end_same_indent(block)
return if block.visible_lines.length != 1
return unless block.visible_lines.first.is_end?
visible_line = block.visible_lines.first
lines = @code_lines[block.lines.first.index..visible_line.index]
matching_kw = lines.reverse.detect { |line| line.indent == block.current_indent && line.is_kw? }
return unless matching_kw
@lines_to_output << matching_kw
kw_count = 0
end_count = 0
orphan_end = @code_lines[matching_kw.index..visible_line.index].detect do |line|
kw_count += 1 if line.is_kw?
end_count += 1 if line.is_end?
end_count >= kw_count
end
return unless orphan_end
@lines_to_output << orphan_end
end
end
end
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