Class: Sexpistol::Parser
- Inherits:
-
StringScanner
- Object
- StringScanner
- Sexpistol::Parser
- Defined in:
- lib/sexpistol/parser.rb
Constant Summary collapse
- PARANTHESES =
/[()]/.freeze
- STRING =
/"([^"\\]|\\.)*"/.freeze
- FLOAT =
/[\-+]? [0-9]+ ((e[0-9]+) | (\.[0-9]+(e[0-9]+)?)) (?=[\s()])/x.freeze
- INTEGER =
/([\-+]?[0-9]+)(?=[\s()])/.freeze
- SYMBOL =
/[^0-9()\s]+[^()\s]*/.freeze
Instance Method Summary collapse
- #convert_ruby_keyword_literals(token) ⇒ Object
- #fetch_token ⇒ Object
-
#initialize(string, parse_ruby_keyword_literals = false) ⇒ Parser
constructor
A new instance of Parser.
- #parse(level = 0, exp = []) ⇒ Object
Constructor Details
#initialize(string, parse_ruby_keyword_literals = false) ⇒ Parser
Returns a new instance of Parser.
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# File 'lib/sexpistol/parser.rb', line 13 def initialize(string, parse_ruby_keyword_literals = false) raise 'String given is not an s-expression' if string.strip[0] != '(' raise 'Invalid s-expression' if string.count('(') != string.count(')') @parse_ruby_keyword_literals = parse_ruby_keyword_literals super(string.strip) end |
Instance Method Details
#convert_ruby_keyword_literals(token) ⇒ Object
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# File 'lib/sexpistol/parser.rb', line 51 def convert_ruby_keyword_literals(token) return token unless @parse_ruby_keyword_literals && token.is_a?(Symbol) case token when :nil then nil when :true then true when :false then false else token end end |
#fetch_token ⇒ Object
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# File 'lib/sexpistol/parser.rb', line 39 def fetch_token skip(/\s+/) return matched if scan(PARANTHESES) return matched.undump if scan(STRING) return matched.to_f if scan(FLOAT) return matched.to_i if scan(INTEGER) return matched.to_sym if scan(SYMBOL) raise "Invalid token at position #{pos} near '#{scan(/.{0,20}/)}'." end |
#parse(level = 0, exp = []) ⇒ Object
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# File 'lib/sexpistol/parser.rb', line 22 def parse(level = 0, exp = []) until eos? case token = fetch_token when ')' then break when '(' then exp << parse(level + 1) when String, Integer, Float, Symbol then exp << convert_ruby_keyword_literals(token) end end if level.zero? exp = exp.first if exp.first.is_a?(Array) && exp.length == 1 exp = Sexpistol::SExpressionArray.new(exp) if exp.all? { |item| item.is_a?(Array) } end exp end |