SyntaxSuggest::CodeSearch

Searches code for a syntax error

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 part.

The bulk of the heavy lifting is done in:

- CodeFrontier (Holds information for generating blocks and determining if we can stop searching)
- ParseBlocksFromLine (Creates blocks into the frontier)
- BlockExpand (Expands existing blocks to search more code)

## Syntax error detection

When the frontier holds the syntax error, we can stop searching

search = CodeSearch.new(<<~EOM)
  def dog
    def lol
  end
EOM

search.call

search.invalid_blocks.map(&:to_s) # =>
# => ["def lol\n"]