1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Generate files suitable for use with [Graphviz](http://www.graphviz.org/)
13 //! The `render` function generates output (e.g. an `output.dot` file) for
14 //! use with [Graphviz](http://www.graphviz.org/) by walking a labelled
15 //! graph. (Graphviz can then automatically lay out the nodes and edges
16 //! of the graph, and also optionally render the graph as an image or
17 //! other [output formats](
18 //! http://www.graphviz.org/content/output-formats), such as SVG.)
20 //! Rather than impose some particular graph data structure on clients,
21 //! this library exposes two traits that clients can implement on their
22 //! own structs before handing them over to the rendering function.
24 //! Note: This library does not yet provide access to the full
25 //! expressiveness of the [DOT language](
26 //! http://www.graphviz.org/doc/info/lang.html). For example, there are
27 //! many [attributes](http://www.graphviz.org/content/attrs) related to
28 //! providing layout hints (e.g. left-to-right versus top-down, which
29 //! algorithm to use, etc). The current intention of this library is to
30 //! emit a human-readable .dot file with very regular structure suitable
31 //! for easy post-processing.
35 //! The first example uses a very simple graph representation: a list of
36 //! pairs of ints, representing the edges (the node set is implicit).
37 //! Each node label is derived directly from the int representing the node,
38 //! while the edge labels are all empty strings.
40 //! This example also illustrates how to use `CowVec` to return
41 //! an owned vector or a borrowed slice as appropriate: we construct the
42 //! node vector from scratch, but borrow the edge list (rather than
43 //! constructing a copy of all the edges from scratch).
45 //! The output from this example renders five nodes, with the first four
46 //! forming a diamond-shaped acyclic graph and then pointing to the fifth
50 //! use std::borrow::IntoCow;
51 //! use graphviz as dot;
54 //! type Ed = (int,int);
55 //! struct Edges(Vec<Ed>);
57 //! pub fn render_to<W:Writer>(output: &mut W) {
58 //! let edges = Edges(vec!((0,1), (0,2), (1,3), (2,3), (3,4), (4,4)));
59 //! dot::render(&edges, output).unwrap()
62 //! impl<'a> dot::Labeller<'a, Nd, Ed> for Edges {
63 //! fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example1").unwrap() }
65 //! fn node_id(&'a self, n: &Nd) -> dot::Id<'a> {
66 //! dot::Id::new(format!("N{}", *n)).unwrap()
70 //! impl<'a> dot::GraphWalk<'a, Nd, Ed> for Edges {
71 //! fn nodes(&self) -> dot::Nodes<'a,Nd> {
72 //! // (assumes that |N| \approxeq |E|)
73 //! let &Edges(ref v) = self;
74 //! let mut nodes = Vec::with_capacity(v.len());
75 //! for &(s,t) in v.iter() {
76 //! nodes.push(s); nodes.push(t);
83 //! fn edges(&'a self) -> dot::Edges<'a,Ed> {
84 //! let &Edges(ref edges) = self;
85 //! edges.as_slice().into_cow()
88 //! fn source(&self, e: &Ed) -> Nd { let &(s,_) = e; s }
90 //! fn target(&self, e: &Ed) -> Nd { let &(_,t) = e; t }
93 //! # pub fn main() { render_to(&mut Vec::new()) }
97 //! # pub fn render_to<W:Writer>(output: &mut W) { unimplemented!() }
99 //! use std::io::File;
100 //! let mut f = File::create(&Path::new("example1.dot"));
101 //! render_to(&mut f)
105 //! Output from first example (in `example1.dot`):
108 //! digraph example1 {
114 //! N0 -> N1[label=""];
115 //! N0 -> N2[label=""];
116 //! N1 -> N3[label=""];
117 //! N2 -> N3[label=""];
118 //! N3 -> N4[label=""];
119 //! N4 -> N4[label=""];
123 //! The second example illustrates using `node_label` and `edge_label` to
124 //! add labels to the nodes and edges in the rendered graph. The graph
125 //! here carries both `nodes` (the label text to use for rendering a
126 //! particular node), and `edges` (again a list of `(source,target)`
129 //! This example also illustrates how to use a type (in this case the edge
130 //! type) that shares substructure with the graph: the edge type here is a
131 //! direct reference to the `(source,target)` pair stored in the graph's
132 //! internal vector (rather than passing around a copy of the pair
133 //! itself). Note that this implies that `fn edges(&'a self)` must
134 //! construct a fresh `Vec<&'a (uint,uint)>` from the `Vec<(uint,uint)>`
135 //! edges stored in `self`.
137 //! Since both the set of nodes and the set of edges are always
138 //! constructed from scratch via iterators, we use the `collect()` method
139 //! from the `Iterator` trait to collect the nodes and edges into freshly
140 //! constructed growable `Vec` values (rather use the `into_cow`
141 //! from the `IntoCow` trait as was used in the first example
144 //! The output from this example renders four nodes that make up the
145 //! Hasse-diagram for the subsets of the set `{x, y}`. Each edge is
146 //! labelled with the ⊆ character (specified using the HTML character
150 //! use std::borrow::IntoCow;
151 //! use graphviz as dot;
154 //! type Ed<'a> = &'a (uint, uint);
155 //! struct Graph { nodes: Vec<&'static str>, edges: Vec<(uint,uint)> }
157 //! pub fn render_to<W:Writer>(output: &mut W) {
158 //! let nodes = vec!("{x,y}","{x}","{y}","{}");
159 //! let edges = vec!((0,1), (0,2), (1,3), (2,3));
160 //! let graph = Graph { nodes: nodes, edges: edges };
162 //! dot::render(&graph, output).unwrap()
165 //! impl<'a> dot::Labeller<'a, Nd, Ed<'a>> for Graph {
166 //! fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example2").unwrap() }
167 //! fn node_id(&'a self, n: &Nd) -> dot::Id<'a> {
168 //! dot::Id::new(format!("N{}", n)).unwrap()
170 //! fn node_label<'b>(&'b self, n: &Nd) -> dot::LabelText<'b> {
171 //! dot::LabelStr(self.nodes[*n].as_slice().into_cow())
173 //! fn edge_label<'b>(&'b self, _: &Ed) -> dot::LabelText<'b> {
174 //! dot::LabelStr("⊆".into_cow())
178 //! impl<'a> dot::GraphWalk<'a, Nd, Ed<'a>> for Graph {
179 //! fn nodes(&self) -> dot::Nodes<'a,Nd> { range(0,self.nodes.len()).collect() }
180 //! fn edges(&'a self) -> dot::Edges<'a,Ed<'a>> { self.edges.iter().collect() }
181 //! fn source(&self, e: &Ed) -> Nd { let & &(s,_) = e; s }
182 //! fn target(&self, e: &Ed) -> Nd { let & &(_,t) = e; t }
185 //! # pub fn main() { render_to(&mut Vec::new()) }
189 //! # pub fn render_to<W:Writer>(output: &mut W) { unimplemented!() }
191 //! use std::io::File;
192 //! let mut f = File::create(&Path::new("example2.dot"));
193 //! render_to(&mut f)
197 //! The third example is similar to the second, except now each node and
198 //! edge now carries a reference to the string label for each node as well
199 //! as that node's index. (This is another illustration of how to share
200 //! structure with the graph itself, and why one might want to do so.)
202 //! The output from this example is the same as the second example: the
203 //! Hasse-diagram for the subsets of the set `{x, y}`.
206 //! use std::borrow::IntoCow;
207 //! use graphviz as dot;
209 //! type Nd<'a> = (uint, &'a str);
210 //! type Ed<'a> = (Nd<'a>, Nd<'a>);
211 //! struct Graph { nodes: Vec<&'static str>, edges: Vec<(uint,uint)> }
213 //! pub fn render_to<W:Writer>(output: &mut W) {
214 //! let nodes = vec!("{x,y}","{x}","{y}","{}");
215 //! let edges = vec!((0,1), (0,2), (1,3), (2,3));
216 //! let graph = Graph { nodes: nodes, edges: edges };
218 //! dot::render(&graph, output).unwrap()
221 //! impl<'a> dot::Labeller<'a, Nd<'a>, Ed<'a>> for Graph {
222 //! fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example3").unwrap() }
223 //! fn node_id(&'a self, n: &Nd<'a>) -> dot::Id<'a> {
224 //! dot::Id::new(format!("N{}", n.0)).unwrap()
226 //! fn node_label<'b>(&'b self, n: &Nd<'b>) -> dot::LabelText<'b> {
228 //! dot::LabelStr(self.nodes[i].as_slice().into_cow())
230 //! fn edge_label<'b>(&'b self, _: &Ed<'b>) -> dot::LabelText<'b> {
231 //! dot::LabelStr("⊆".into_cow())
235 //! impl<'a> dot::GraphWalk<'a, Nd<'a>, Ed<'a>> for Graph {
236 //! fn nodes(&'a self) -> dot::Nodes<'a,Nd<'a>> {
237 //! self.nodes.iter().map(|s|s.as_slice()).enumerate().collect()
239 //! fn edges(&'a self) -> dot::Edges<'a,Ed<'a>> {
240 //! self.edges.iter()
241 //! .map(|&(i,j)|((i, self.nodes[i].as_slice()),
242 //! (j, self.nodes[j].as_slice())))
245 //! fn source(&self, e: &Ed<'a>) -> Nd<'a> { let &(s,_) = e; s }
246 //! fn target(&self, e: &Ed<'a>) -> Nd<'a> { let &(_,t) = e; t }
249 //! # pub fn main() { render_to(&mut Vec::new()) }
253 //! # pub fn render_to<W:Writer>(output: &mut W) { unimplemented!() }
255 //! use std::io::File;
256 //! let mut f = File::create(&Path::new("example3.dot"));
257 //! render_to(&mut f)
263 //! * [Graphviz](http://www.graphviz.org/)
265 //! * [DOT language](http://www.graphviz.org/doc/info/lang.html)
267 #![crate_name = "graphviz"]
269 #![crate_type = "rlib"]
270 #![crate_type = "dylib"]
271 #![doc(html_logo_url = "http://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
272 html_favicon_url = "http://www.rust-lang.org/favicon.ico",
273 html_root_url = "http://doc.rust-lang.org/nightly/")]
274 #![feature(globs, slicing_syntax)]
275 #![feature(unboxed_closures)]
277 pub use self::LabelText::*;
279 use std::borrow::IntoCow;
281 use std::str::CowString;
282 use std::vec::CowVec;
284 pub mod maybe_owned_vec;
286 /// The text for a graphviz label on a node or edge.
287 pub enum LabelText<'a> {
288 /// This kind of label preserves the text directly as is.
290 /// Occurrences of backslashes (`\`) are escaped, and thus appear
291 /// as backslashes in the rendered label.
292 LabelStr(CowString<'a>),
294 /// This kind of label uses the graphviz label escString type:
295 /// http://www.graphviz.org/content/attrs#kescString
297 /// Occurrences of backslashes (`\`) are not escaped; instead they
298 /// are interpreted as initiating an escString escape sequence.
300 /// Escape sequences of particular interest: in addition to `\n`
301 /// to break a line (centering the line preceding the `\n`), there
302 /// are also the escape sequences `\l` which left-justifies the
303 /// preceding line and `\r` which right-justifies it.
304 EscStr(CowString<'a>),
307 // There is a tension in the design of the labelling API.
309 // For example, I considered making a `Labeller<T>` trait that
310 // provides labels for `T`, and then making the graph type `G`
311 // implement `Labeller<Node>` and `Labeller<Edge>`. However, this is
312 // not possible without functional dependencies. (One could work
313 // around that, but I did not explore that avenue heavily.)
315 // Another approach that I actually used for a while was to make a
316 // `Label<Context>` trait that is implemented by the client-specific
317 // Node and Edge types (as well as an implementation on Graph itself
318 // for the overall name for the graph). The main disadvantage of this
319 // second approach (compared to having the `G` type parameter
320 // implement a Labelling service) that I have encountered is that it
321 // makes it impossible to use types outside of the current crate
322 // directly as Nodes/Edges; you need to wrap them in newtype'd
323 // structs. See e.g. the `No` and `Ed` structs in the examples. (In
324 // practice clients using a graph in some other crate would need to
325 // provide some sort of adapter shim over the graph anyway to
326 // interface with this library).
328 // Another approach would be to make a single `Labeller<N,E>` trait
329 // that provides three methods (graph_label, node_label, edge_label),
330 // and then make `G` implement `Labeller<N,E>`. At first this did not
331 // appeal to me, since I had thought I would need separate methods on
332 // each data variant for dot-internal identifiers versus user-visible
333 // labels. However, the identifier/label distinction only arises for
334 // nodes; graphs themselves only have identifiers, and edges only have
337 // So in the end I decided to use the third approach described above.
339 /// `Id` is a Graphviz `ID`.
345 /// Creates an `Id` named `name`.
347 /// The caller must ensure that the input conforms to an
348 /// identifier format: it must be a non-empty string made up of
349 /// alphanumeric or underscore characters, not beginning with a
350 /// digit (i.e. the regular expression `[a-zA-Z_][a-zA-Z_0-9]*`).
352 /// (Note: this format is a strict subset of the `ID` format
353 /// defined by the DOT language. This function may change in the
354 /// future to accept a broader subset, or the entirety, of DOT's
357 /// Passing an invalid string (containing spaces, brackets,
358 /// quotes, ...) will return an empty `Err` value.
359 pub fn new<Name: IntoCow<'a, String, str>>(name: Name) -> Result<Id<'a>, ()> {
360 let name = name.into_cow();
362 let mut chars = name.chars();
364 Some(c) if is_letter_or_underscore(c) => { ; },
367 if !chars.all(is_constituent) {
371 return Ok(Id{ name: name });
373 fn is_letter_or_underscore(c: char) -> bool {
374 in_range('a', c, 'z') || in_range('A', c, 'Z') || c == '_'
376 fn is_constituent(c: char) -> bool {
377 is_letter_or_underscore(c) || in_range('0', c, '9')
379 fn in_range(low: char, c: char, high: char) -> bool {
380 low as uint <= c as uint && c as uint <= high as uint
384 pub fn as_slice(&'a self) -> &'a str {
388 pub fn name(self) -> CowString<'a> {
393 /// Each instance of a type that implements `Label<C>` maps to a
394 /// unique identifier with respect to `C`, which is used to identify
395 /// it in the generated .dot file. They can also provide more
396 /// elaborate (and non-unique) label text that is used in the graphviz
399 /// The graph instance is responsible for providing the DOT compatible
400 /// identifiers for the nodes and (optionally) rendered labels for the nodes and
401 /// edges, as well as an identifier for the graph itself.
402 pub trait Labeller<'a,N,E> {
403 /// Must return a DOT compatible identifier naming the graph.
404 fn graph_id(&'a self) -> Id<'a>;
406 /// Maps `n` to a unique identifier with respect to `self`. The
407 /// implementer is responsible for ensuring that the returned name
408 /// is a valid DOT identifier.
409 fn node_id(&'a self, n: &N) -> Id<'a>;
411 /// Maps `n` to a label that will be used in the rendered output.
412 /// The label need not be unique, and may be the empty string; the
413 /// default is just the output from `node_id`.
414 fn node_label(&'a self, n: &N) -> LabelText<'a> {
415 LabelStr(self.node_id(n).name)
418 /// Maps `e` to a label that will be used in the rendered output.
419 /// The label need not be unique, and may be the empty string; the
420 /// default is in fact the empty string.
421 fn edge_label(&'a self, e: &E) -> LabelText<'a> {
423 LabelStr("".into_cow())
427 impl<'a> LabelText<'a> {
428 pub fn label<S:IntoCow<'a, String, str>>(s: S) -> LabelText<'a> {
429 LabelStr(s.into_cow())
432 pub fn escaped<S:IntoCow<'a, String, str>>(s: S) -> LabelText<'a> {
436 fn escape_char<F>(c: char, mut f: F) where F: FnMut(char) {
438 // not escaping \\, since Graphviz escString needs to
439 // interpret backslashes; see EscStr above.
441 _ => for c in c.escape_default() { f(c) }
444 fn escape_str(s: &str) -> String {
445 let mut out = String::with_capacity(s.len());
447 LabelText::escape_char(c, |c| out.push(c));
452 /// Renders text as string suitable for a label in a .dot file.
453 pub fn escape(&self) -> String {
455 &LabelStr(ref s) => s.escape_default(),
456 &EscStr(ref s) => LabelText::escape_str(s[]),
460 /// Decomposes content into string suitable for making EscStr that
461 /// yields same content as self. The result obeys the law
462 /// render(`lt`) == render(`EscStr(lt.pre_escaped_content())`) for
463 /// all `lt: LabelText`.
464 fn pre_escaped_content(self) -> CowString<'a> {
467 LabelStr(s) => if s.contains_char('\\') {
468 (&*s).escape_default().into_cow()
475 /// Puts `prefix` on a line above this label, with a blank line separator.
476 pub fn prefix_line(self, prefix: LabelText) -> LabelText<'static> {
477 prefix.suffix_line(self)
480 /// Puts `suffix` on a line below this label, with a blank line separator.
481 pub fn suffix_line(self, suffix: LabelText) -> LabelText<'static> {
482 let mut prefix = self.pre_escaped_content().into_owned();
483 let suffix = suffix.pre_escaped_content();
484 prefix.push_str(r"\n\n");
485 prefix.push_str(suffix[]);
486 EscStr(prefix.into_cow())
490 pub type Nodes<'a,N> = CowVec<'a,N>;
491 pub type Edges<'a,E> = CowVec<'a,E>;
493 // (The type parameters in GraphWalk should be associated items,
494 // when/if Rust supports such.)
496 /// GraphWalk is an abstraction over a directed graph = (nodes,edges)
497 /// made up of node handles `N` and edge handles `E`, where each `E`
498 /// can be mapped to its source and target nodes.
500 /// The lifetime parameter `'a` is exposed in this trait (rather than
501 /// introduced as a generic parameter on each method declaration) so
502 /// that a client impl can choose `N` and `E` that have substructure
503 /// that is bound by the self lifetime `'a`.
505 /// The `nodes` and `edges` method each return instantiations of
506 /// `CowVec` to leave implementers the freedom to create
507 /// entirely new vectors or to pass back slices into internally owned
509 pub trait GraphWalk<'a, N, E> {
510 /// Returns all the nodes in this graph.
511 fn nodes(&'a self) -> Nodes<'a, N>;
512 /// Returns all of the edges in this graph.
513 fn edges(&'a self) -> Edges<'a, E>;
514 /// The source node for `edge`.
515 fn source(&'a self, edge: &E) -> N;
516 /// The target node for `edge`.
517 fn target(&'a self, edge: &E) -> N;
520 #[deriving(Copy, PartialEq, Eq, Show)]
521 pub enum RenderOption {
526 /// Returns vec holding all the default render options.
527 pub fn default_options() -> Vec<RenderOption> { vec![] }
529 /// Renders directed graph `g` into the writer `w` in DOT syntax.
530 /// (Simple wrapper around `render_opts` that passes a default set of options.)
531 pub fn render<'a, N:Clone+'a, E:Clone+'a, G:Labeller<'a,N,E>+GraphWalk<'a,N,E>, W:Writer>(
533 w: &mut W) -> io::IoResult<()> {
534 render_opts(g, w, &[])
537 /// Renders directed graph `g` into the writer `w` in DOT syntax.
538 /// (Main entry point for the library.)
539 pub fn render_opts<'a, N:Clone+'a, E:Clone+'a, G:Labeller<'a,N,E>+GraphWalk<'a,N,E>, W:Writer>(
542 options: &[RenderOption]) -> io::IoResult<()>
544 fn writeln<W:Writer>(w: &mut W, arg: &[&str]) -> io::IoResult<()> {
545 for &s in arg.iter() { try!(w.write_str(s)); }
549 fn indent<W:Writer>(w: &mut W) -> io::IoResult<()> {
553 try!(writeln(w, &["digraph ", g.graph_id().as_slice(), " {"]));
554 for n in g.nodes().iter() {
556 let id = g.node_id(n);
557 if options.contains(&RenderOption::NoNodeLabels) {
558 try!(writeln(w, &[id.as_slice(), ";"]));
560 let escaped = g.node_label(n).escape();
561 try!(writeln(w, &[id.as_slice(),
562 "[label=\"", escaped.as_slice(), "\"];"]));
566 for e in g.edges().iter() {
567 let escaped_label = g.edge_label(e).escape();
569 let source = g.source(e);
570 let target = g.target(e);
571 let source_id = g.node_id(&source);
572 let target_id = g.node_id(&target);
573 if options.contains(&RenderOption::NoEdgeLabels) {
574 try!(writeln(w, &[source_id.as_slice(),
575 " -> ", target_id.as_slice(), ";"]));
577 try!(writeln(w, &[source_id.as_slice(),
578 " -> ", target_id.as_slice(),
579 "[label=\"", escaped_label.as_slice(), "\"];"]));
588 use self::NodeLabels::*;
589 use super::{Id, LabelText, LabelStr, EscStr, Labeller};
590 use super::{Nodes, Edges, GraphWalk, render};
591 use std::io::IoResult;
593 use std::borrow::IntoCow;
595 /// each node is an index in a vector in the graph.
598 from: uint, to: uint, label: &'static str
601 fn edge(from: uint, to: uint, label: &'static str) -> Edge {
602 Edge { from: from, to: to, label: label }
605 struct LabelledGraph {
606 /// The name for this graph. Used for labelling generated `digraph`.
609 /// Each node is an index into `node_labels`; these labels are
610 /// used as the label text for each node. (The node *names*,
611 /// which are unique identifiers, are derived from their index
614 /// If a node maps to None here, then just use its name as its
616 node_labels: Vec<Option<&'static str>>,
618 /// Each edge relates a from-index to a to-index along with a
619 /// label; `edges` collects them.
623 // A simple wrapper around LabelledGraph that forces the labels to
624 // be emitted as EscStr.
625 struct LabelledGraphWithEscStrs {
630 AllNodesLabelled(Vec<L>),
631 UnlabelledNodes(uint),
632 SomeNodesLabelled(Vec<Option<L>>),
635 type Trivial = NodeLabels<&'static str>;
637 impl NodeLabels<&'static str> {
638 fn to_opt_strs(self) -> Vec<Option<&'static str>> {
641 => Vec::from_elem(len, None).into_iter().collect(),
642 AllNodesLabelled(lbls)
643 => lbls.into_iter().map(
644 |l|Some(l)).collect(),
645 SomeNodesLabelled(lbls)
646 => lbls.into_iter().collect(),
652 fn new(name: &'static str,
653 node_labels: Trivial,
654 edges: Vec<Edge>) -> LabelledGraph {
657 node_labels: node_labels.to_opt_strs(),
663 impl LabelledGraphWithEscStrs {
664 fn new(name: &'static str,
665 node_labels: Trivial,
666 edges: Vec<Edge>) -> LabelledGraphWithEscStrs {
667 LabelledGraphWithEscStrs {
668 graph: LabelledGraph::new(name, node_labels, edges)
673 fn id_name<'a>(n: &Node) -> Id<'a> {
674 Id::new(format!("N{}", *n)).unwrap()
677 impl<'a> Labeller<'a, Node, &'a Edge> for LabelledGraph {
678 fn graph_id(&'a self) -> Id<'a> {
679 Id::new(self.name[]).unwrap()
681 fn node_id(&'a self, n: &Node) -> Id<'a> {
684 fn node_label(&'a self, n: &Node) -> LabelText<'a> {
685 match self.node_labels[*n] {
686 Some(ref l) => LabelStr(l.into_cow()),
687 None => LabelStr(id_name(n).name()),
690 fn edge_label(&'a self, e: & &'a Edge) -> LabelText<'a> {
691 LabelStr(e.label.into_cow())
695 impl<'a> Labeller<'a, Node, &'a Edge> for LabelledGraphWithEscStrs {
696 fn graph_id(&'a self) -> Id<'a> { self.graph.graph_id() }
697 fn node_id(&'a self, n: &Node) -> Id<'a> { self.graph.node_id(n) }
698 fn node_label(&'a self, n: &Node) -> LabelText<'a> {
699 match self.graph.node_label(n) {
700 LabelStr(s) | EscStr(s) => EscStr(s),
703 fn edge_label(&'a self, e: & &'a Edge) -> LabelText<'a> {
704 match self.graph.edge_label(e) {
705 LabelStr(s) | EscStr(s) => EscStr(s),
710 impl<'a> GraphWalk<'a, Node, &'a Edge> for LabelledGraph {
711 fn nodes(&'a self) -> Nodes<'a,Node> {
712 range(0u, self.node_labels.len()).collect()
714 fn edges(&'a self) -> Edges<'a,&'a Edge> {
715 self.edges.iter().collect()
717 fn source(&'a self, edge: & &'a Edge) -> Node {
720 fn target(&'a self, edge: & &'a Edge) -> Node {
725 impl<'a> GraphWalk<'a, Node, &'a Edge> for LabelledGraphWithEscStrs {
726 fn nodes(&'a self) -> Nodes<'a,Node> {
729 fn edges(&'a self) -> Edges<'a,&'a Edge> {
732 fn source(&'a self, edge: & &'a Edge) -> Node {
735 fn target(&'a self, edge: & &'a Edge) -> Node {
740 fn test_input(g: LabelledGraph) -> IoResult<String> {
741 let mut writer = Vec::new();
742 render(&g, &mut writer).unwrap();
743 (&mut writer.as_slice()).read_to_string()
746 // All of the tests use raw-strings as the format for the expected outputs,
747 // so that you can cut-and-paste the content into a .dot file yourself to
748 // see what the graphviz visualizer would produce.
752 let labels : Trivial = UnlabelledNodes(0);
753 let r = test_input(LabelledGraph::new("empty_graph", labels, vec!()));
754 assert_eq!(r.unwrap(),
755 r#"digraph empty_graph {
762 let labels : Trivial = UnlabelledNodes(1);
763 let r = test_input(LabelledGraph::new("single_node", labels, vec!()));
764 assert_eq!(r.unwrap(),
765 r#"digraph single_node {
773 let labels : Trivial = UnlabelledNodes(2);
774 let result = test_input(LabelledGraph::new("single_edge", labels,
775 vec!(edge(0, 1, "E"))));
776 assert_eq!(result.unwrap(),
777 r#"digraph single_edge {
786 fn test_some_labelled() {
787 let labels : Trivial = SomeNodesLabelled(vec![Some("A"), None]);
788 let result = test_input(LabelledGraph::new("test_some_labelled", labels,
789 vec![edge(0, 1, "A-1")]));
790 assert_eq!(result.unwrap(),
791 r#"digraph test_some_labelled {
794 N0 -> N1[label="A-1"];
800 fn single_cyclic_node() {
801 let labels : Trivial = UnlabelledNodes(1);
802 let r = test_input(LabelledGraph::new("single_cyclic_node", labels,
803 vec!(edge(0, 0, "E"))));
804 assert_eq!(r.unwrap(),
805 r#"digraph single_cyclic_node {
814 let labels = AllNodesLabelled(vec!("{x,y}", "{x}", "{y}", "{}"));
815 let r = test_input(LabelledGraph::new(
816 "hasse_diagram", labels,
817 vec!(edge(0, 1, ""), edge(0, 2, ""),
818 edge(1, 3, ""), edge(2, 3, ""))));
819 assert_eq!(r.unwrap(),
820 r#"digraph hasse_diagram {
834 fn left_aligned_text() {
835 let labels = AllNodesLabelled(vec!(
847 let mut writer = Vec::new();
849 let g = LabelledGraphWithEscStrs::new(
850 "syntax_tree", labels,
851 vec!(edge(0, 1, "then"), edge(0, 2, "else"),
852 edge(1, 3, ";"), edge(2, 3, ";" )));
854 render(&g, &mut writer).unwrap();
855 let r = (&mut writer.as_slice()).read_to_string();
857 assert_eq!(r.unwrap(),
858 r#"digraph syntax_tree {
859 N0[label="if test {\l branch1\l} else {\l branch2\l}\lafterward\l"];
862 N3[label="afterward"];
863 N0 -> N1[label="then"];
864 N0 -> N2[label="else"];
872 fn simple_id_construction() {
873 let id1 = Id::new("hello");
876 Err(_) => panic!("'hello' is not a valid value for id anymore")
881 fn badly_formatted_id() {
882 let id2 = Id::new("Weird { struct : ure } !!!");
884 Ok(_) => panic!("graphviz id suddenly allows spaces, brackets and stuff"),