Fix invalid expect block and support for multi-line errors

[GreasySlug]

Fixes #58 and #248.

Each line of the REPL is now evaluated by the Parser::eval() (Parser and Lex are not modified)

Changes proposed in this PR:

• Add Runnable Parser to check invalid syntax
• Check invalid block as a error
• Add block_begin to use for REPL
• Display multi-line error

@mtshiba

[GreasySlug]

Currently it is implemented only in dummy.rs. Is it necessary to implement run() other than dummy.rs?

[mtshiba]

A method should be added to Runnable trait as a required method to determine if the next line should be followed. The name should be something like .expect_nextline(src). And each struct should implement it. So no need to implement run.

[GreasySlug]

I fixed conflict.

[GreasySlug]

However, not evaluated until only a newline is entered after the block is expected Invalid syntax can be entered during this time

e.g.

>>> while True, do!: 
...   ->
...     =>
...       ->
... 

Furthermore, another approach is needed to evaluate during the block Each row is now evaluated by Parser Changed to use instance.eval() to initialize lines and display errors when Parser results in an error

>>> while True, do: 
...    ->
Error[#0000]: File <stdin>, line 2, 

2 |    ->
  :    --

invalid syntax

Error[#0390]: File <stdin>, line 2,

2 |    ->
  :      -

failed to parse a block

[GreasySlug]

I fixed #281 then I found some bugs. so I need more time to test and fix them

[mtshiba]

When REPL detects an error, it refers to the previous source information.

[GreasySlug]

I addressed the issue occurring during single-line errors.

Additionally, I added error handling for cases where newline are expected, such as with do!:, do:, to ensure evaluation in the REPL.

[mtshiba]

REPL references previous source information when dealing with multiple lines of code.

[GreasySlug]

• Multi line errors

• Collections

[mtshiba]

Thank you!