1 //! Generate files suitable for use with [Graphviz](http://www.graphviz.org/)
3 //! The `render` function generates output (e.g., an `output.dot` file) for
4 //! use with [Graphviz](http://www.graphviz.org/) by walking a labeled
5 //! graph. (Graphviz can then automatically lay out the nodes and edges
6 //! of the graph, and also optionally render the graph as an image or
7 //! other [output formats](
8 //! http://www.graphviz.org/content/output-formats), such as SVG.)
10 //! Rather than impose some particular graph data structure on clients,
11 //! this library exposes two traits that clients can implement on their
12 //! own structs before handing them over to the rendering function.
14 //! Note: This library does not yet provide access to the full
15 //! expressiveness of the [DOT language](
16 //! http://www.graphviz.org/doc/info/lang.html). For example, there are
17 //! many [attributes](http://www.graphviz.org/content/attrs) related to
18 //! providing layout hints (e.g., left-to-right versus top-down, which
19 //! algorithm to use, etc). The current intention of this library is to
20 //! emit a human-readable .dot file with very regular structure suitable
21 //! for easy post-processing.
25 //! The first example uses a very simple graph representation: a list of
26 //! pairs of ints, representing the edges (the node set is implicit).
27 //! Each node label is derived directly from the int representing the node,
28 //! while the edge labels are all empty strings.
30 //! This example also illustrates how to use `Cow<[T]>` to return
31 //! an owned vector or a borrowed slice as appropriate: we construct the
32 //! node vector from scratch, but borrow the edge list (rather than
33 //! constructing a copy of all the edges from scratch).
35 //! The output from this example renders five nodes, with the first four
36 //! forming a diamond-shaped acyclic graph and then pointing to the fifth
40 //! #![feature(rustc_private)]
42 //! use std::io::Write;
43 //! use graphviz as dot;
46 //! type Ed = (isize,isize);
47 //! struct Edges(Vec<Ed>);
49 //! pub fn render_to<W: Write>(output: &mut W) {
50 //! let edges = Edges(vec![(0,1), (0,2), (1,3), (2,3), (3,4), (4,4)]);
51 //! dot::render(&edges, output).unwrap()
54 //! impl<'a> dot::Labeller<'a> for Edges {
57 //! fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example1").unwrap() }
59 //! fn node_id(&'a self, n: &Nd) -> dot::Id<'a> {
60 //! dot::Id::new(format!("N{}", *n)).unwrap()
64 //! impl<'a> dot::GraphWalk<'a> for Edges {
67 //! fn nodes(&self) -> dot::Nodes<'a,Nd> {
68 //! // (assumes that |N| \approxeq |E|)
69 //! let &Edges(ref v) = self;
70 //! let mut nodes = Vec::with_capacity(v.len());
72 //! nodes.push(s); nodes.push(t);
79 //! fn edges(&'a self) -> dot::Edges<'a,Ed> {
80 //! let &Edges(ref edges) = self;
81 //! (&edges[..]).into()
84 //! fn source(&self, e: &Ed) -> Nd { let &(s,_) = e; s }
86 //! fn target(&self, e: &Ed) -> Nd { let &(_,t) = e; t }
89 //! # pub fn main() { render_to(&mut Vec::new()) }
93 //! # pub fn render_to<W:std::io::Write>(output: &mut W) { unimplemented!() }
95 //! use std::fs::File;
96 //! let mut f = File::create("example1.dot").unwrap();
101 //! Output from first example (in `example1.dot`):
104 //! digraph example1 {
110 //! N0 -> N1[label=""];
111 //! N0 -> N2[label=""];
112 //! N1 -> N3[label=""];
113 //! N2 -> N3[label=""];
114 //! N3 -> N4[label=""];
115 //! N4 -> N4[label=""];
119 //! The second example illustrates using `node_label` and `edge_label` to
120 //! add labels to the nodes and edges in the rendered graph. The graph
121 //! here carries both `nodes` (the label text to use for rendering a
122 //! particular node), and `edges` (again a list of `(source,target)`
125 //! This example also illustrates how to use a type (in this case the edge
126 //! type) that shares substructure with the graph: the edge type here is a
127 //! direct reference to the `(source,target)` pair stored in the graph's
128 //! internal vector (rather than passing around a copy of the pair
129 //! itself). Note that this implies that `fn edges(&'a self)` must
130 //! construct a fresh `Vec<&'a (usize,usize)>` from the `Vec<(usize,usize)>`
131 //! edges stored in `self`.
133 //! Since both the set of nodes and the set of edges are always
134 //! constructed from scratch via iterators, we use the `collect()` method
135 //! from the `Iterator` trait to collect the nodes and edges into freshly
136 //! constructed growable `Vec` values (rather than using `Cow` as in the
137 //! first example above).
139 //! The output from this example renders four nodes that make up the
140 //! Hasse-diagram for the subsets of the set `{x, y}`. Each edge is
141 //! labeled with the ⊆ character (specified using the HTML character
145 //! #![feature(rustc_private)]
147 //! use std::io::Write;
148 //! use graphviz as dot;
151 //! type Ed<'a> = &'a (usize, usize);
152 //! struct Graph { nodes: Vec<&'static str>, edges: Vec<(usize,usize)> }
154 //! pub fn render_to<W: Write>(output: &mut W) {
155 //! let nodes = vec!["{x,y}","{x}","{y}","{}"];
156 //! let edges = vec![(0,1), (0,2), (1,3), (2,3)];
157 //! let graph = Graph { nodes: nodes, edges: edges };
159 //! dot::render(&graph, output).unwrap()
162 //! impl<'a> dot::Labeller<'a> for Graph {
164 //! type Edge = Ed<'a>;
165 //! fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example2").unwrap() }
166 //! fn node_id(&'a self, n: &Nd) -> dot::Id<'a> {
167 //! dot::Id::new(format!("N{}", n)).unwrap()
169 //! fn node_label<'b>(&'b self, n: &Nd) -> dot::LabelText<'b> {
170 //! dot::LabelText::LabelStr(self.nodes[*n].into())
172 //! fn edge_label<'b>(&'b self, _: &Ed) -> dot::LabelText<'b> {
173 //! dot::LabelText::LabelStr("⊆".into())
177 //! impl<'a> dot::GraphWalk<'a> for Graph {
179 //! type Edge = Ed<'a>;
180 //! fn nodes(&self) -> dot::Nodes<'a,Nd> { (0..self.nodes.len()).collect() }
181 //! fn edges(&'a self) -> dot::Edges<'a,Ed<'a>> { self.edges.iter().collect() }
182 //! fn source(&self, e: &Ed) -> Nd { let & &(s,_) = e; s }
183 //! fn target(&self, e: &Ed) -> Nd { let & &(_,t) = e; t }
186 //! # pub fn main() { render_to(&mut Vec::new()) }
190 //! # pub fn render_to<W:std::io::Write>(output: &mut W) { unimplemented!() }
192 //! use std::fs::File;
193 //! let mut f = File::create("example2.dot").unwrap();
194 //! render_to(&mut f)
198 //! The third example is similar to the second, except now each node and
199 //! edge now carries a reference to the string label for each node as well
200 //! as that node's index. (This is another illustration of how to share
201 //! structure with the graph itself, and why one might want to do so.)
203 //! The output from this example is the same as the second example: the
204 //! Hasse-diagram for the subsets of the set `{x, y}`.
207 //! #![feature(rustc_private)]
209 //! use std::io::Write;
210 //! use graphviz as dot;
212 //! type Nd<'a> = (usize, &'a str);
213 //! type Ed<'a> = (Nd<'a>, Nd<'a>);
214 //! struct Graph { nodes: Vec<&'static str>, edges: Vec<(usize,usize)> }
216 //! pub fn render_to<W: Write>(output: &mut W) {
217 //! let nodes = vec!["{x,y}","{x}","{y}","{}"];
218 //! let edges = vec![(0,1), (0,2), (1,3), (2,3)];
219 //! let graph = Graph { nodes: nodes, edges: edges };
221 //! dot::render(&graph, output).unwrap()
224 //! impl<'a> dot::Labeller<'a> for Graph {
225 //! type Node = Nd<'a>;
226 //! type Edge = Ed<'a>;
227 //! fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example3").unwrap() }
228 //! fn node_id(&'a self, n: &Nd<'a>) -> dot::Id<'a> {
229 //! dot::Id::new(format!("N{}", n.0)).unwrap()
231 //! fn node_label<'b>(&'b self, n: &Nd<'b>) -> dot::LabelText<'b> {
233 //! dot::LabelText::LabelStr(self.nodes[i].into())
235 //! fn edge_label<'b>(&'b self, _: &Ed<'b>) -> dot::LabelText<'b> {
236 //! dot::LabelText::LabelStr("⊆".into())
240 //! impl<'a> dot::GraphWalk<'a> for Graph {
241 //! type Node = Nd<'a>;
242 //! type Edge = Ed<'a>;
243 //! fn nodes(&'a self) -> dot::Nodes<'a,Nd<'a>> {
244 //! self.nodes.iter().map(|s| &s[..]).enumerate().collect()
246 //! fn edges(&'a self) -> dot::Edges<'a,Ed<'a>> {
247 //! self.edges.iter()
248 //! .map(|&(i,j)|((i, &self.nodes[i][..]),
249 //! (j, &self.nodes[j][..])))
252 //! fn source(&self, e: &Ed<'a>) -> Nd<'a> { let &(s,_) = e; s }
253 //! fn target(&self, e: &Ed<'a>) -> Nd<'a> { let &(_,t) = e; t }
256 //! # pub fn main() { render_to(&mut Vec::new()) }
260 //! # pub fn render_to<W:std::io::Write>(output: &mut W) { unimplemented!() }
262 //! use std::fs::File;
263 //! let mut f = File::create("example3.dot").unwrap();
264 //! render_to(&mut f)
270 //! * [Graphviz](http://www.graphviz.org/)
272 //! * [DOT language](http://www.graphviz.org/doc/info/lang.html)
274 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/",
275 test(attr(allow(unused_variables), deny(warnings))))]
277 #![deny(rust_2018_idioms)]
283 use std::borrow::Cow;
284 use std::io::prelude::*;
287 /// The text for a graphviz label on a node or edge.
288 pub enum LabelText<'a> {
289 /// This kind of label preserves the text directly as is.
291 /// Occurrences of backslashes (`\`) are escaped, and thus appear
292 /// as backslashes in the rendered label.
293 LabelStr(Cow<'a, str>),
295 /// This kind of label uses the graphviz label escString type:
296 /// <http://www.graphviz.org/content/attrs#kescString>
298 /// Occurrences of backslashes (`\`) are not escaped; instead they
299 /// are interpreted as initiating an escString escape sequence.
301 /// Escape sequences of particular interest: in addition to `\n`
302 /// to break a line (centering the line preceding the `\n`), there
303 /// are also the escape sequences `\l` which left-justifies the
304 /// preceding line and `\r` which right-justifies it.
305 EscStr(Cow<'a, str>),
307 /// This uses a graphviz [HTML string label][html]. The string is
308 /// printed exactly as given, but between `<` and `>`. **No
309 /// escaping is performed.**
311 /// [html]: http://www.graphviz.org/content/node-shapes#html
312 HtmlStr(Cow<'a, str>),
315 /// The style for a node or edge.
316 /// See <http://www.graphviz.org/doc/info/attrs.html#k:style> for descriptions.
317 /// Note that some of these are not valid for edges.
318 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
333 pub fn as_slice(self) -> &'static str {
336 Style::Solid => "solid",
337 Style::Dashed => "dashed",
338 Style::Dotted => "dotted",
339 Style::Bold => "bold",
340 Style::Rounded => "rounded",
341 Style::Diagonals => "diagonals",
342 Style::Filled => "filled",
343 Style::Striped => "striped",
344 Style::Wedged => "wedged",
349 // There is a tension in the design of the labelling API.
351 // For example, I considered making a `Labeller<T>` trait that
352 // provides labels for `T`, and then making the graph type `G`
353 // implement `Labeller<Node>` and `Labeller<Edge>`. However, this is
354 // not possible without functional dependencies. (One could work
355 // around that, but I did not explore that avenue heavily.)
357 // Another approach that I actually used for a while was to make a
358 // `Label<Context>` trait that is implemented by the client-specific
359 // Node and Edge types (as well as an implementation on Graph itself
360 // for the overall name for the graph). The main disadvantage of this
361 // second approach (compared to having the `G` type parameter
362 // implement a Labelling service) that I have encountered is that it
363 // makes it impossible to use types outside of the current crate
364 // directly as Nodes/Edges; you need to wrap them in newtype'd
365 // structs. See e.g., the `No` and `Ed` structs in the examples. (In
366 // practice clients using a graph in some other crate would need to
367 // provide some sort of adapter shim over the graph anyway to
368 // interface with this library).
370 // Another approach would be to make a single `Labeller<N,E>` trait
371 // that provides three methods (graph_label, node_label, edge_label),
372 // and then make `G` implement `Labeller<N,E>`. At first this did not
373 // appeal to me, since I had thought I would need separate methods on
374 // each data variant for dot-internal identifiers versus user-visible
375 // labels. However, the identifier/label distinction only arises for
376 // nodes; graphs themselves only have identifiers, and edges only have
379 // So in the end I decided to use the third approach described above.
381 /// `Id` is a Graphviz `ID`.
387 /// Creates an `Id` named `name`.
389 /// The caller must ensure that the input conforms to an
390 /// identifier format: it must be a non-empty string made up of
391 /// alphanumeric or underscore characters, not beginning with a
392 /// digit (i.e., the regular expression `[a-zA-Z_][a-zA-Z_0-9]*`).
394 /// (Note: this format is a strict subset of the `ID` format
395 /// defined by the DOT language. This function may change in the
396 /// future to accept a broader subset, or the entirety, of DOT's
399 /// Passing an invalid string (containing spaces, brackets,
400 /// quotes, ...) will return an empty `Err` value.
401 pub fn new<Name: Into<Cow<'a, str>>>(name: Name) -> Result<Id<'a>, ()> {
402 let name = name.into();
403 match name.chars().next() {
404 Some(c) if c.is_ascii_alphabetic() || c == '_' => {}
407 if !name.chars().all(|c| c.is_ascii_alphanumeric() || c == '_' ) {
414 pub fn as_slice(&'a self) -> &'a str {
418 pub fn name(self) -> Cow<'a, str> {
423 /// Each instance of a type that implements `Label<C>` maps to a
424 /// unique identifier with respect to `C`, which is used to identify
425 /// it in the generated .dot file. They can also provide more
426 /// elaborate (and non-unique) label text that is used in the graphviz
429 /// The graph instance is responsible for providing the DOT compatible
430 /// identifiers for the nodes and (optionally) rendered labels for the nodes and
431 /// edges, as well as an identifier for the graph itself.
432 pub trait Labeller<'a> {
436 /// Must return a DOT compatible identifier naming the graph.
437 fn graph_id(&'a self) -> Id<'a>;
439 /// Maps `n` to a unique identifier with respect to `self`. The
440 /// implementor is responsible for ensuring that the returned name
441 /// is a valid DOT identifier.
442 fn node_id(&'a self, n: &Self::Node) -> Id<'a>;
444 /// Maps `n` to one of the [graphviz `shape` names][1]. If `None`
445 /// is returned, no `shape` attribute is specified.
447 /// [1]: http://www.graphviz.org/content/node-shapes
448 fn node_shape(&'a self, _node: &Self::Node) -> Option<LabelText<'a>> {
452 /// Maps `n` to a label that will be used in the rendered output.
453 /// The label need not be unique, and may be the empty string; the
454 /// default is just the output from `node_id`.
455 fn node_label(&'a self, n: &Self::Node) -> LabelText<'a> {
456 LabelStr(self.node_id(n).name)
459 /// Maps `e` to a label that will be used in the rendered output.
460 /// The label need not be unique, and may be the empty string; the
461 /// default is in fact the empty string.
462 fn edge_label(&'a self, _e: &Self::Edge) -> LabelText<'a> {
466 /// Maps `n` to a style that will be used in the rendered output.
467 fn node_style(&'a self, _n: &Self::Node) -> Style {
471 /// Maps `e` to a style that will be used in the rendered output.
472 fn edge_style(&'a self, _e: &Self::Edge) -> Style {
477 /// Escape tags in such a way that it is suitable for inclusion in a
478 /// Graphviz HTML label.
479 pub fn escape_html(s: &str) -> String {
480 s.replace("&", "&")
481 .replace("\"", """)
482 .replace("<", "<")
483 .replace(">", ">")
486 impl<'a> LabelText<'a> {
487 pub fn label<S: Into<Cow<'a, str>>>(s: S) -> LabelText<'a> {
491 pub fn escaped<S: Into<Cow<'a, str>>>(s: S) -> LabelText<'a> {
495 pub fn html<S: Into<Cow<'a, str>>>(s: S) -> LabelText<'a> {
499 fn escape_char<F>(c: char, mut f: F)
503 // not escaping \\, since Graphviz escString needs to
504 // interpret backslashes; see EscStr above.
507 for c in c.escape_default() {
513 fn escape_str(s: &str) -> String {
514 let mut out = String::with_capacity(s.len());
516 LabelText::escape_char(c, |c| out.push(c));
521 /// Renders text as string suitable for a label in a .dot file.
522 /// This includes quotes or suitable delimiters.
523 pub fn to_dot_string(&self) -> String {
525 LabelStr(ref s) => format!("\"{}\"", s.escape_default()),
526 EscStr(ref s) => format!("\"{}\"", LabelText::escape_str(&s)),
527 HtmlStr(ref s) => format!("<{}>", s),
531 /// Decomposes content into string suitable for making EscStr that
532 /// yields same content as self. The result obeys the law
533 /// render(`lt`) == render(`EscStr(lt.pre_escaped_content())`) for
534 /// all `lt: LabelText`.
535 fn pre_escaped_content(self) -> Cow<'a, str> {
539 if s.contains('\\') {
540 (&*s).escape_default().to_string().into()
549 /// Puts `prefix` on a line above this label, with a blank line separator.
550 pub fn prefix_line(self, prefix: LabelText<'_>) -> LabelText<'static> {
551 prefix.suffix_line(self)
554 /// Puts `suffix` on a line below this label, with a blank line separator.
555 pub fn suffix_line(self, suffix: LabelText<'_>) -> LabelText<'static> {
556 let mut prefix = self.pre_escaped_content().into_owned();
557 let suffix = suffix.pre_escaped_content();
558 prefix.push_str(r"\n\n");
559 prefix.push_str(&suffix);
560 EscStr(prefix.into())
564 pub type Nodes<'a,N> = Cow<'a,[N]>;
565 pub type Edges<'a,E> = Cow<'a,[E]>;
567 // (The type parameters in GraphWalk should be associated items,
568 // when/if Rust supports such.)
570 /// GraphWalk is an abstraction over a directed graph = (nodes,edges)
571 /// made up of node handles `N` and edge handles `E`, where each `E`
572 /// can be mapped to its source and target nodes.
574 /// The lifetime parameter `'a` is exposed in this trait (rather than
575 /// introduced as a generic parameter on each method declaration) so
576 /// that a client impl can choose `N` and `E` that have substructure
577 /// that is bound by the self lifetime `'a`.
579 /// The `nodes` and `edges` method each return instantiations of
580 /// `Cow<[T]>` to leave implementors the freedom to create
581 /// entirely new vectors or to pass back slices into internally owned
583 pub trait GraphWalk<'a> {
587 /// Returns all the nodes in this graph.
588 fn nodes(&'a self) -> Nodes<'a, Self::Node>;
589 /// Returns all of the edges in this graph.
590 fn edges(&'a self) -> Edges<'a, Self::Edge>;
591 /// The source node for `edge`.
592 fn source(&'a self, edge: &Self::Edge) -> Self::Node;
593 /// The target node for `edge`.
594 fn target(&'a self, edge: &Self::Edge) -> Self::Node;
597 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
598 pub enum RenderOption {
605 /// Returns vec holding all the default render options.
606 pub fn default_options() -> Vec<RenderOption> {
610 /// Renders directed graph `g` into the writer `w` in DOT syntax.
611 /// (Simple wrapper around `render_opts` that passes a default set of options.)
612 pub fn render<'a,N,E,G,W>(g: &'a G, w: &mut W) -> io::Result<()>
615 G: Labeller<'a, Node=N, Edge=E> + GraphWalk<'a, Node=N, Edge=E>,
618 render_opts(g, w, &[])
621 /// Renders directed graph `g` into the writer `w` in DOT syntax.
622 /// (Main entry point for the library.)
623 pub fn render_opts<'a, N, E, G, W>(g: &'a G,
625 options: &[RenderOption])
629 G: Labeller<'a, Node=N, Edge=E> + GraphWalk<'a, Node=N, Edge=E>,
632 writeln!(w, "digraph {} {{", g.graph_id().as_slice())?;
633 for n in g.nodes().iter() {
635 let id = g.node_id(n);
637 let escaped = &g.node_label(n).to_dot_string();
639 let mut text = Vec::new();
640 write!(text, "{}", id.as_slice()).unwrap();
642 if !options.contains(&RenderOption::NoNodeLabels) {
643 write!(text, "[label={}]", escaped).unwrap();
646 let style = g.node_style(n);
647 if !options.contains(&RenderOption::NoNodeStyles) && style != Style::None {
648 write!(text, "[style=\"{}\"]", style.as_slice()).unwrap();
651 if let Some(s) = g.node_shape(n) {
652 write!(text, "[shape={}]", &s.to_dot_string()).unwrap();
655 writeln!(text, ";").unwrap();
656 w.write_all(&text[..])?;
659 for e in g.edges().iter() {
660 let escaped_label = &g.edge_label(e).to_dot_string();
662 let source = g.source(e);
663 let target = g.target(e);
664 let source_id = g.node_id(&source);
665 let target_id = g.node_id(&target);
667 let mut text = Vec::new();
668 write!(text, "{} -> {}", source_id.as_slice(), target_id.as_slice()).unwrap();
670 if !options.contains(&RenderOption::NoEdgeLabels) {
671 write!(text, "[label={}]", escaped_label).unwrap();
674 let style = g.edge_style(e);
675 if !options.contains(&RenderOption::NoEdgeStyles) && style != Style::None {
676 write!(text, "[style=\"{}\"]", style.as_slice()).unwrap();
679 writeln!(text, ";").unwrap();
680 w.write_all(&text[..])?;
689 use super::{Id, Labeller, Nodes, Edges, GraphWalk, render, Style};
690 use super::LabelText::{self, LabelStr, EscStr, HtmlStr};
692 use std::io::prelude::*;
694 /// each node is an index in a vector in the graph.
703 fn edge(from: usize, to: usize, label: &'static str, style: Style) -> Edge {
712 struct LabelledGraph {
713 /// The name for this graph. Used for labeling generated `digraph`.
716 /// Each node is an index into `node_labels`; these labels are
717 /// used as the label text for each node. (The node *names*,
718 /// which are unique identifiers, are derived from their index
721 /// If a node maps to None here, then just use its name as its
723 node_labels: Vec<Option<&'static str>>,
725 node_styles: Vec<Style>,
727 /// Each edge relates a from-index to a to-index along with a
728 /// label; `edges` collects them.
732 // A simple wrapper around LabelledGraph that forces the labels to
733 // be emitted as EscStr.
734 struct LabelledGraphWithEscStrs {
735 graph: LabelledGraph,
739 AllNodesLabelled(Vec<L>),
740 UnlabelledNodes(usize),
741 SomeNodesLabelled(Vec<Option<L>>),
744 type Trivial = NodeLabels<&'static str>;
746 impl NodeLabels<&'static str> {
747 fn to_opt_strs(self) -> Vec<Option<&'static str>> {
749 UnlabelledNodes(len) => vec![None; len],
750 AllNodesLabelled(lbls) => lbls.into_iter().map(|l| Some(l)).collect(),
751 SomeNodesLabelled(lbls) => lbls.into_iter().collect(),
755 fn len(&self) -> usize {
757 &UnlabelledNodes(len) => len,
758 &AllNodesLabelled(ref lbls) => lbls.len(),
759 &SomeNodesLabelled(ref lbls) => lbls.len(),
765 fn new(name: &'static str,
766 node_labels: Trivial,
768 node_styles: Option<Vec<Style>>)
770 let count = node_labels.len();
773 node_labels: node_labels.to_opt_strs(),
775 node_styles: match node_styles {
776 Some(nodes) => nodes,
777 None => vec![Style::None; count],
783 impl LabelledGraphWithEscStrs {
784 fn new(name: &'static str,
785 node_labels: Trivial,
787 -> LabelledGraphWithEscStrs {
788 LabelledGraphWithEscStrs { graph: LabelledGraph::new(name, node_labels, edges, None) }
792 fn id_name<'a>(n: &Node) -> Id<'a> {
793 Id::new(format!("N{}", *n)).unwrap()
796 impl<'a> Labeller<'a> for LabelledGraph {
798 type Edge = &'a Edge;
799 fn graph_id(&'a self) -> Id<'a> {
800 Id::new(self.name).unwrap()
802 fn node_id(&'a self, n: &Node) -> Id<'a> {
805 fn node_label(&'a self, n: &Node) -> LabelText<'a> {
806 match self.node_labels[*n] {
807 Some(l) => LabelStr(l.into()),
808 None => LabelStr(id_name(n).name()),
811 fn edge_label(&'a self, e: &&'a Edge) -> LabelText<'a> {
812 LabelStr(e.label.into())
814 fn node_style(&'a self, n: &Node) -> Style {
817 fn edge_style(&'a self, e: &&'a Edge) -> Style {
822 impl<'a> Labeller<'a> for LabelledGraphWithEscStrs {
824 type Edge = &'a Edge;
825 fn graph_id(&'a self) -> Id<'a> {
826 self.graph.graph_id()
828 fn node_id(&'a self, n: &Node) -> Id<'a> {
829 self.graph.node_id(n)
831 fn node_label(&'a self, n: &Node) -> LabelText<'a> {
832 match self.graph.node_label(n) {
833 LabelStr(s) | EscStr(s) | HtmlStr(s) => EscStr(s),
836 fn edge_label(&'a self, e: &&'a Edge) -> LabelText<'a> {
837 match self.graph.edge_label(e) {
838 LabelStr(s) | EscStr(s) | HtmlStr(s) => EscStr(s),
843 impl<'a> GraphWalk<'a> for LabelledGraph {
845 type Edge = &'a Edge;
846 fn nodes(&'a self) -> Nodes<'a, Node> {
847 (0..self.node_labels.len()).collect()
849 fn edges(&'a self) -> Edges<'a, &'a Edge> {
850 self.edges.iter().collect()
852 fn source(&'a self, edge: &&'a Edge) -> Node {
855 fn target(&'a self, edge: &&'a Edge) -> Node {
860 impl<'a> GraphWalk<'a> for LabelledGraphWithEscStrs {
862 type Edge = &'a Edge;
863 fn nodes(&'a self) -> Nodes<'a, Node> {
866 fn edges(&'a self) -> Edges<'a, &'a Edge> {
869 fn source(&'a self, edge: &&'a Edge) -> Node {
872 fn target(&'a self, edge: &&'a Edge) -> Node {
877 fn test_input(g: LabelledGraph) -> io::Result<String> {
878 let mut writer = Vec::new();
879 render(&g, &mut writer).unwrap();
880 let mut s = String::new();
881 Read::read_to_string(&mut &*writer, &mut s)?;
885 // All of the tests use raw-strings as the format for the expected outputs,
886 // so that you can cut-and-paste the content into a .dot file yourself to
887 // see what the graphviz visualizer would produce.
891 let labels: Trivial = UnlabelledNodes(0);
892 let r = test_input(LabelledGraph::new("empty_graph", labels, vec![], None));
893 assert_eq!(r.unwrap(),
894 r#"digraph empty_graph {
901 let labels: Trivial = UnlabelledNodes(1);
902 let r = test_input(LabelledGraph::new("single_node", labels, vec![], None));
903 assert_eq!(r.unwrap(),
904 r#"digraph single_node {
911 fn single_node_with_style() {
912 let labels: Trivial = UnlabelledNodes(1);
913 let styles = Some(vec![Style::Dashed]);
914 let r = test_input(LabelledGraph::new("single_node", labels, vec![], styles));
915 assert_eq!(r.unwrap(),
916 r#"digraph single_node {
917 N0[label="N0"][style="dashed"];
924 let labels: Trivial = UnlabelledNodes(2);
925 let result = test_input(LabelledGraph::new("single_edge",
927 vec![edge(0, 1, "E", Style::None)],
929 assert_eq!(result.unwrap(),
930 r#"digraph single_edge {
939 fn single_edge_with_style() {
940 let labels: Trivial = UnlabelledNodes(2);
941 let result = test_input(LabelledGraph::new("single_edge",
943 vec![edge(0, 1, "E", Style::Bold)],
945 assert_eq!(result.unwrap(),
946 r#"digraph single_edge {
949 N0 -> N1[label="E"][style="bold"];
955 fn test_some_labelled() {
956 let labels: Trivial = SomeNodesLabelled(vec![Some("A"), None]);
957 let styles = Some(vec![Style::None, Style::Dotted]);
958 let result = test_input(LabelledGraph::new("test_some_labelled",
960 vec![edge(0, 1, "A-1", Style::None)],
962 assert_eq!(result.unwrap(),
963 r#"digraph test_some_labelled {
965 N1[label="N1"][style="dotted"];
966 N0 -> N1[label="A-1"];
972 fn single_cyclic_node() {
973 let labels: Trivial = UnlabelledNodes(1);
974 let r = test_input(LabelledGraph::new("single_cyclic_node",
976 vec![edge(0, 0, "E", Style::None)],
978 assert_eq!(r.unwrap(),
979 r#"digraph single_cyclic_node {
988 let labels = AllNodesLabelled(vec!["{x,y}", "{x}", "{y}", "{}"]);
989 let r = test_input(LabelledGraph::new("hasse_diagram",
991 vec![edge(0, 1, "", Style::None),
992 edge(0, 2, "", Style::None),
993 edge(1, 3, "", Style::None),
994 edge(2, 3, "", Style::None)],
996 assert_eq!(r.unwrap(),
997 r#"digraph hasse_diagram {
1011 fn left_aligned_text() {
1012 let labels = AllNodesLabelled(vec![
1024 let mut writer = Vec::new();
1026 let g = LabelledGraphWithEscStrs::new("syntax_tree",
1028 vec![edge(0, 1, "then", Style::None),
1029 edge(0, 2, "else", Style::None),
1030 edge(1, 3, ";", Style::None),
1031 edge(2, 3, ";", Style::None)]);
1033 render(&g, &mut writer).unwrap();
1034 let mut r = String::new();
1035 Read::read_to_string(&mut &*writer, &mut r).unwrap();
1038 r#"digraph syntax_tree {
1039 N0[label="if test {\l branch1\l} else {\l branch2\l}\lafterward\l"];
1040 N1[label="branch1"];
1041 N2[label="branch2"];
1042 N3[label="afterward"];
1043 N0 -> N1[label="then"];
1044 N0 -> N2[label="else"];
1045 N1 -> N3[label=";"];
1046 N2 -> N3[label=";"];
1052 fn simple_id_construction() {
1053 let id1 = Id::new("hello");
1056 Err(..) => panic!("'hello' is not a valid value for id anymore"),
1061 fn badly_formatted_id() {
1062 let id2 = Id::new("Weird { struct : ure } !!!");
1064 Ok(_) => panic!("graphviz id suddenly allows spaces, brackets and stuff"),