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% this is just being used as a namespace
classdef reader
methods (Static = true)
function tokens = tokenize(str)
re = '[\s,]*(~@|[\[\]{}()''`~^@]|"(?:\\.|[^\\"])*"|;.*|[^\s\[\]{}(''"`,;)]*)';
% extract the capture group (to ignore spaces and commas)
tokens = cellfun(@(x) x(1), regexp(str, re, 'tokens'));
end
function atm = read_atom(rdr)
token = rdr.next();
%fprintf('in read_atom: %s\n', token);
if not(isempty(regexp(token, '^-?[0-9]+$', 'match')))
atm = str2double(token);
elseif strcmp(token(1), '"')
atm = token(2:length(token)-1);
%else if token eq 'nil'
elseif strcmp(token, 'true')
atm = true;
elseif strcmp(token, 'false')
atm = false;
else
atm = types.Symbol(token);
end
end
function lst = read_list(rdr)
%fprintf('in read_list\n');
lst = {};
token = rdr.next();
if not(strcmp(token, '('))
error('expected ''(''');
end
token = rdr.peek();
while true
if eq(token, false)
error('expected '')''');
end
if strcmp(token, ')'), break, end
lst{length(lst)+1} = reader.read_form(rdr);
token = rdr.peek();
end
rdr.next();
end
function ast = read_form(rdr)
%fprintf('in read_form\n');
token = rdr.peek();
switch token(1)
case ')'
error('unexpected '')''');
case '('
ast = reader.read_list(rdr);
otherwise
ast = reader.read_atom(rdr);
end
end
function ast = read_str(str)
%fprintf('in read_str\n');
tokens = reader.tokenize(str);
rdr = Reader(tokens);
ast = reader.read_form(rdr);
end
end
end
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