class SyntaxSuggest::LeftRightLexCount
Find
mis-matched syntax based on lexical count
Used for detecting missing pairs of elements each keyword needs an end, each ‘{’ needs a ‘}’ etc.
Example:
left_right = LeftRightLexCount.new left_right.count_kw left_right.missing.first # => "end" left_right = LeftRightLexCount.new source = "{ a: b, c: d" # Note missing '}' LexAll.new(source: source).each do |lex| left_right.count_lex(lex) end left_right.missing.first # => "}"
Constants
- PAIRS
Public Class Methods
Source
# File lib/syntax_suggest/left_right_lex_count.rb, line 25 def initialize @kw_count = 0 @end_count = 0 @count_for_char = { "{" => 0, "}" => 0, "[" => 0, "]" => 0, "(" => 0, ")" => 0, "|" => 0 } end
Public Instance Methods
Source
# File lib/syntax_suggest/left_right_lex_count.rb, line 44 def count_end @end_count += 1 end
Source
# File lib/syntax_suggest/left_right_lex_count.rb, line 101 def count_for_char(char) @count_for_char[char] end
Source
# File lib/syntax_suggest/left_right_lex_count.rb, line 40 def count_kw @kw_count += 1 end
Source
# File lib/syntax_suggest/left_right_lex_count.rb, line 58 def count_lex(lex) case lex.type when :on_tstring_content # ^^^ # Means it's a string or a symbol `"{"` rather than being # part of a data structure (like a hash) `{ a: b }` # ignore it. when :on_words_beg, :on_symbos_beg, :on_qwords_beg, :on_qsymbols_beg, :on_regexp_beg, :on_tstring_beg # ^^^ # Handle shorthand syntaxes like `%Q{ i am a string }` # # The start token will be the full thing `%Q{` but we # need to count it as if it's a `{`. Any token # can be used char = lex.token[-1] @count_for_char[char] += 1 if @count_for_char.key?(char) when :on_embexpr_beg # ^^^ # Embedded string expressions like `"#{foo} <-embed"` # are parsed with chars: # # `#{` as :on_embexpr_beg # `}` as :on_embexpr_end # # We cannot ignore both :on_emb_expr_beg and :on_embexpr_end # because sometimes the lexer thinks something is an embed # string end, when it is not like `lol = }` (no clue why). # # When we see `#{` count it as a `{` or we will # have a mis-match count. # case lex.token when "\#{" @count_for_char["{"] += 1 end else @end_count += 1 if lex.is_end? @kw_count += 1 if lex.is_kw? @count_for_char[lex.token] += 1 if @count_for_char.key?(lex.token) end end
Count source code characters
Example:
left_right = LeftRightLexCount.new left_right.count_lex(LexValue.new(1, :on_lbrace, "{", Ripper::EXPR_BEG)) left_right.count_for_char("{") # => 1 left_right.count_for_char("}") # => 0
Source
# File lib/syntax_suggest/left_right_lex_count.rb, line 110 def missing out = missing_pairs out << missing_pipe out << missing_keyword_end out.compact! out end
Returns an array of missing syntax characters or ‘“end”` or `“keyword”`
left_right.missing # => ["}"]
Private Instance Methods
Source
# File lib/syntax_suggest/left_right_lex_count.rb, line 148 def missing_keyword_end case @kw_count <=> @end_count when 1 "end" when 0 nil when -1 "keyword" end end
Keywords need ends and ends need keywords
If we have more keywords, there’s a missing ‘end` if we have more `end`-s, there’s a missing keyword
Source
# File lib/syntax_suggest/left_right_lex_count.rb, line 131 def missing_pairs PAIRS.map do |(left, right)| case @count_for_char[left] <=> @count_for_char[right] when 1 right when 0 nil when -1 left end end end
Opening characters like ‘{` need closing characters # like `}`.
When a mis-match count is detected, suggest the missing member.
For example if there are 3 ‘}` and only two `{` return `“{”`
Source
# File lib/syntax_suggest/left_right_lex_count.rb, line 162 def missing_pipe if @count_for_char["|"].odd? "|" end end
Pipes come in pairs. If there’s an odd number of pipes then we are missing one