JSON.parse can't parse special characters

[Blacksmoke16]

JSON.parse errors when parsing strings with special chars, e.x. \t or \n.

https://play.crystal-lang.org/#/r/7qpu

require "json"

puts JSON.parse %({"body": "A bunch of data\tyo"})

Unhandled exception: Unexpected char '	' at 1:26 (JSON::ParseException)
  from /usr/lib/crystal/json/lexer.cr:371:7 in 'raise'
  from /usr/lib/crystal/json/lexer.cr:367:5 in 'unexpected_char'
  from /usr/lib/crystal/json/lexer.cr:366:11 in 'unexpected_char'
  from /usr/lib/crystal/json/lexer/string_based.cr:28:11 in 'consume_string'
  from /usr/lib/crystal/json/lexer.cr:61:37 in 'next_token'
  from /usr/lib/crystal/json/parser.cr:108:11 in 'next_token'
  from /usr/lib/crystal/json/parser.cr:83:11 in 'parse_object'
  from /usr/lib/crystal/json/parser.cr:35:7 in 'parse_value'
  from /usr/lib/crystal/json/parser.cr:13:12 in 'parse'
  from /usr/lib/crystal/json.cr:137:5 in 'parse'
  from /eval:3:6 in '__crystal_main'
  from /usr/lib/crystal/crystal/main.cr:97:5 in 'main_user_code'
  from /usr/lib/crystal/crystal/main.cr:86:7 in 'main'
  from /usr/lib/crystal/crystal/main.cr:106:3 in 'main'
  from __libc_start_main
  from _start
  from ???

Discovered while doing some manual testing of Blacksmoke16/oq#37.

[asterite]

The exact same program fails in Ruby too: https://carc.in/#/r/7qrf

According to the JSON spec, a string is any codepoint except ", \ or control characters.

[yxhuvud]

Do note that it works everywhere (including in Javascript) if you escape the \ with another \.