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simplify

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vonhyou 2021-04-15 01:00:40 +08:00
parent 7ac16ca74e
commit dc17338d40
1 changed files with 17 additions and 13 deletions
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30
prol.rb
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@ -20,15 +20,20 @@ module Lisp
program.gsub('(', ' ( ').gsub(')', ' ) ').split program.gsub('(', ' ( ').gsub(')', ' ) ').split
end end
def self.make_list(tokens)
lst = []
lst << read_tokens(tokens) while tokens[0] != ')'
tokens.shift
lst
end
def self.read_tokens(tokens, lst = []) def self.read_tokens(tokens, lst = [])
# read expressions from token # read expressions from token
raise SyntaxError, 'Unexpected EOF' if tokens.empty? raise SyntaxError, 'Unexpected EOF' if tokens.empty?
case token = tokens.shift case token = tokens.shift
when '(' when '('
lst << read_tokens(tokens) while tokens[0] != ')' make_list tokens
tokens.shift
lst
when ')' when ')'
raise SyntaxError, "Unexpected ')'" raise SyntaxError, "Unexpected ')'"
else else
@ -55,16 +60,15 @@ module Lisp
scope.merge op => ->(*args) { args.inject(&op) } scope.merge op => ->(*args) { args.inject(&op) }
end end
end end
mtds = { 'min': ->(arr) { arr.min }, lisp_methods = { 'min': ->(arr) { arr.min },
'max': ->(arr) { arr.max }, 'max': ->(arr) { arr.max },
'car': ->(arr) { arr[0] }, 'car': ->(arr) { arr[0] },
'cdr': ->(arr) { arr[1..-1] }, 'cdr': ->(arr) { arr[1..-1] },
'cons': ->(arr) { arr }, 'cons': ->(arr) { arr },
'quote': ->(*args) { args }, 'quote': ->(*args) { args },
'print': ->(arg) { p arg }, 'print': ->(arg) { p arg },
'begin': ->(*_args) { true } 'begin': ->(*_args) { true }}
} @global_env.merge lisp_methods
@global_env.merge mtds
end end
##### Lisp Eval ##### Lisp Eval