Current File : //proc/thread-self/root/opt/alt/ruby32/share/ruby/syntax_suggest/block_expand.rb
# frozen_string_literal: true
module SyntaxSuggest
# This class is responsible for taking a code block that exists
# at a far indentaion and then iteratively increasing the block
# so that it captures everything within the same indentation block.
#
# def dog
# puts "bow"
# puts "wow"
# end
#
# block = BlockExpand.new(code_lines: code_lines)
# .call(CodeBlock.new(lines: code_lines[1]))
#
# puts block.to_s
# # => puts "bow"
# puts "wow"
#
#
# Once a code block has captured everything at a given indentation level
# then it will expand to capture surrounding indentation.
#
# block = BlockExpand.new(code_lines: code_lines)
# .call(block)
#
# block.to_s
# # => def dog
# puts "bow"
# puts "wow"
# end
#
class BlockExpand
def initialize(code_lines:)
@code_lines = code_lines
end
# Main interface. Expand current indentation, before
# expanding to a lower indentation
def call(block)
if (next_block = expand_neighbors(block))
next_block
else
expand_indent(block)
end
end
# Expands code to the next lowest indentation
#
# For example:
#
# 1 def dog
# 2 print "dog"
# 3 end
#
# If a block starts on line 2 then it has captured all it's "neighbors" (code at
# the same indentation or higher). To continue expanding, this block must capture
# lines one and three which are at a different indentation level.
#
# This method allows fully expanded blocks to decrease their indentation level (so
# they can expand to capture more code up and down). It does this conservatively
# as there's no undo (currently).
def expand_indent(block)
now = AroundBlockScan.new(code_lines: @code_lines, block: block)
.force_add_hidden
.stop_after_kw
.scan_adjacent_indent
now.lookahead_balance_one_line
now.code_block
end
# A neighbor is code that is at or above the current indent line.
#
# First we build a block with all neighbors. If we can't go further
# then we decrease the indentation threshold and expand via indentation
# i.e. `expand_indent`
#
# Handles two general cases.
#
# ## Case #1: Check code inside of methods/classes/etc.
#
# It's important to note, that not everything in a given indentation level can be parsed
# as valid code even if it's part of valid code. For example:
#
# 1 hash = {
# 2 name: "richard",
# 3 dog: "cinco",
# 4 }
#
# In this case lines 2 and 3 will be neighbors, but they're invalid until `expand_indent`
# is called on them.
#
# When we are adding code within a method or class (at the same indentation level),
# use the empty lines to denote the programmer intended logical chunks.
# Stop and check each one. For example:
#
# 1 def dog
# 2 print "dog"
# 3
# 4 hash = {
# 5 end
#
# If we did not stop parsing at empty newlines then the block might mistakenly grab all
# the contents (lines 2, 3, and 4) and report them as being problems, instead of only
# line 4.
#
# ## Case #2: Expand/grab other logical blocks
#
# Once the search algorithm has converted all lines into blocks at a given indentation
# it will then `expand_indent`. Once the blocks that generates are expanded as neighbors
# we then begin seeing neighbors being other logical blocks i.e. a block's neighbors
# may be another method or class (something with keywords/ends).
#
# For example:
#
# 1 def bark
# 2
# 3 end
# 4
# 5 def sit
# 6 end
#
# In this case if lines 4, 5, and 6 are in a block when it tries to expand neighbors
# it will expand up. If it stops after line 2 or 3 it may cause problems since there's a
# valid kw/end pair, but the block will be checked without it.
#
# We try to resolve this edge case with `lookahead_balance_one_line` below.
def expand_neighbors(block)
now = AroundBlockScan.new(code_lines: @code_lines, block: block)
# Initial scan
now
.force_add_hidden
.stop_after_kw
.scan_neighbors_not_empty
# Slurp up empties
now
.scan_while { |line| line.empty? }
# If next line is kw and it will balance us, take it
expanded_lines = now
.lookahead_balance_one_line
.lines
# Don't allocate a block if it won't be used
#
# If nothing was taken, return nil to indicate that status
# used in `def call` to determine if
# we need to expand up/out (`expand_indent`)
if block.lines == expanded_lines
nil
else
CodeBlock.new(lines: expanded_lines)
end
end
# Managable rspec errors
def inspect
"#<SyntaxSuggest::CodeBlock:0x0000123843lol >"
end
end
end
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