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# File 'lib/fractify/fraction.rb', line 309
def self.validate_string(string)
stage = 0
open_bracket, incorrect_syntax, at_end, digit_present = false
minus_is_free = true
string.each_char do |c|
if at_end || letter?(c)
incorrect_syntax = true
break
end
if open_bracket
if stage.zero?
if c == '-' && minus_is_free
minus_is_free = false
elsif numeric?(c)
digit_present = true
elsif c == ' ' && digit_present
stage = 1
minus_is_free = true
digit_present = false
elsif c == '/' && digit_present
stage = 2
minus_is_free = true
digit_present = false
elsif c == ')' && digit_present
else
incorrect_syntax = true
break
end
elsif stage == 1
if c == '-' && minus_is_free
minus_is_free = false
elsif numeric?(c)
digit_present = true
elsif c == '/' && digit_present
stage = 2
minus_is_free = true
digit_present
else
incorrect_syntax = true
break
end
elsif stage == 2
if c == '-' && minus_is_free
minus_is_free = false
elsif numeric?(c)
digit_present = true
elsif c == ')' && digit_present
else
incorrect_syntax = true
break
end
end
end
if c == '('
if open_bracket
incorrect_syntax = true
break
end
open_bracket = true
elsif c == ')'
unless open_bracket
incorrect_syntax = true
break
end
open_bracket = false
at_end = true
end
end
incorrect_syntax = true if open_bracket
!incorrect_syntax
end
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