diff options
Diffstat (limited to 'graphviz.tlv')
| -rw-r--r-- | graphviz.tlv | 84 |
1 files changed, 83 insertions, 1 deletions
diff --git a/graphviz.tlv b/graphviz.tlv index 54a6404..e79b592 100644 --- a/graphviz.tlv +++ b/graphviz.tlv @@ -564,10 +564,18 @@ > return self:string() > elseif c == '<' then > error('html strings are not implemented yet') - > elseif string.pos('-.0123456789', c) then + > elseif c == '-' then + > if self.chars.peek2 == '-' or self.chars.peek2 == '>' then + > return self:edgeop() + > else + > return self:numeral() + > end + > elseif string.pos('.0123456789', c) then > return self:numeral() > elseif string.match(c, '[%a_]') then > return self:identifier() + > else + > error('unexpected character '..str(c)) > end > end, > skip_whitespace_and_comments = function(self) @@ -654,6 +662,9 @@ > end > return result > end, + > edgeop = function(self) + > return self.chars:read()..self.chars:read() + > end, > } >end > @@ -673,3 +684,74 @@ > check_tokenizer('"abc def" 124', '"abc def"', 'tokenizer: string') > check_tokenizer('', nil, 'tokenizer: eof') >end +- __teliva_timestamp: original + parse_graph: + >-- https://graphviz.org/doc/info/lang.html + >function parse_graph(tokens, graph) + > local t = tokens:read() + > if t == 'strict' then + > t = tokens:read() + > end + > if t == 'graph' then + > error('undirected graphs not supported just yet') + > elseif t == 'digraph' then + > return parse_directed_graph(tokens, graph) + > else + > error('parse_graph: unexpected token '..t) + > end + >end +- __teliva_timestamp: + >Fri Mar 18 16:52:39 2022 + skip_attr_list: + >function skip_attr_list(tokens) + > while true do + > local tok = tokens:read() + > if tok == nil then + > error('unterminated attr list; looked for "]" in vain') + > end + > if tok == ']' then break end + > end + >end +- __teliva_timestamp: + >Fri Mar 18 17:01:49 2022 + parse_directed_graph: + >function parse_directed_graph(tokens, graph) + > tokens:read() -- skip name + > assert(tokens:read() == '{') + > while true do + > if tokens:peek() == nil then + > error('file not terminated with "}"') + > end + > if tokens:peek() == '}' then break end + > local tok1 = tokens:read() + > if tok1 == '[' then + > skip_attr_list(tokens) + > else + > local tok2 = tokens:read() + > if tok2 == '[' then + > -- node_stmt + > skip_attr_list(tokens) + > -- otherwise ignore node declarations; + > -- we'll assume the graph is fully connected + > -- and we can focus on just edges + > elseif tok2 == '->' then + > -- edge_stmt + > local tok3 = tokens:read() + > if graph[tok1] == nil then + > graph[tok1] = {tok3} + > else + > append(graph[tok1], {tok3}) + > end + > elseif tok2 == '--' then + > error('unexpected token "--" in digraph; edges should be directed using "->"') + > elseif tok2 == '=' then + > -- id '=' id + > -- skip + > tokens:read() + > else + > error('unexpected token '..tok2) + > end + > end + > end + > assert(tokens:read() == '}') + >end |