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8a19f60386
- Reorder README to have implementation list after "learning tool" bullet. - This also moves tests/ and libs/ into impls. It would be preferrable to have these directories at the top level. However, this causes difficulties with the wasm implementations which need pre-open directories and have trouble with paths starting with "../../". So in lieu of that, symlink those directories to the top-level. - Move the run_argv_test.sh script into the tests directory for general hygiene.
87 lines
2.5 KiB
Ruby
87 lines
2.5 KiB
Ruby
require_relative "types"
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class Reader
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def initialize(tokens)
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@position = 0
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@tokens = tokens
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end
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def peek
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return @tokens[@position]
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end
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def next
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@position += 1
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return @tokens[@position-1]
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end
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end
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def tokenize(str)
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re = /[\s,]*(~@|[\[\]{}()'`~^@]|"(?:\\.|[^\\"])*"?|;.*|[^\s\[\]{}('"`,;)]*)/
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return str.scan(re).map{|m| m[0]}.select{ |t|
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t != "" && t[0..0] != ";"
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}
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end
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def parse_str(t) # trim and unescape
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return t[1..-2].gsub(/\\./, {"\\\\" => "\\", "\\n" => "\n", "\\\"" => '"'})
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end
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def read_atom(rdr)
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token = rdr.next
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return case token
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when /^-?[0-9]+$/ then token.to_i # integer
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when /^-?[0-9][0-9.]*$/ then token.to_f # float
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when /^"(?:\\.|[^\\"])*"$/ then parse_str(token) # string
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when /^"/ then raise "expected '\"', got EOF"
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when /^:/ then "\u029e" + token[1..-1] # keyword
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when "nil" then nil
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when "true" then true
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when "false" then false
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else token.to_sym # symbol
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end
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end
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def read_list(rdr, klass, start="(", last =")")
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ast = klass.new
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token = rdr.next()
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if token != start
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raise "expected '" + start + "'"
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end
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while (token = rdr.peek) != last
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if not token
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raise "expected '" + last + "', got EOF"
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end
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ast.push(read_form(rdr))
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end
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rdr.next
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return ast
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end
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def read_form(rdr)
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return case rdr.peek
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when ";" then nil
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when "'" then rdr.next; List.new [:quote, read_form(rdr)]
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when "`" then rdr.next; List.new [:quasiquote, read_form(rdr)]
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when "~" then rdr.next; List.new [:unquote, read_form(rdr)]
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when "~@" then rdr.next; List.new [:"splice-unquote", read_form(rdr)]
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when "^" then rdr.next; meta = read_form(rdr);
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List.new [:"with-meta", read_form(rdr), meta]
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when "@" then rdr.next; List.new [:deref, read_form(rdr)]
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when "(" then read_list(rdr, List, "(", ")")
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when ")" then raise "unexpected ')'"
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when "[" then read_list(rdr, Vector, "[", "]")
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when "]" then raise "unexpected ']'"
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when "{" then Hash[read_list(rdr, List, "{", "}").each_slice(2).to_a]
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when "}" then raise "unexpected '}'"
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else read_atom(rdr)
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end
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end
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def read_str(str)
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tokens = tokenize(str)
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return nil if tokens.size == 0
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return read_form(Reader.new(tokens))
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end
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