matlab: step0 and step1 basics.

1 files changed, 66 insertions, 0 deletions

diff --git a/matlab/reader.m b/matlab/reader.m
new file mode 100644
index 0000000..8c752c9
--- /dev/null
+++ b/matlab/reader.m
@@ -0,0 +1,66 @@
+% 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