1 // Copyright 2014-2015 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 `Cow<[T]>` 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 //! #![feature(rustc_private)]
52 //! use graphviz::IntoCow;
53 //! use std::io::Write;
54 //! use graphviz as dot;
57 //! type Ed = (isize,isize);
58 //! struct Edges(Vec<Ed>);
60 //! pub fn render_to<W: Write>(output: &mut W) {
61 //! let edges = Edges(vec![(0,1), (0,2), (1,3), (2,3), (3,4), (4,4)]);
62 //! dot::render(&edges, output).unwrap()
65 //! impl<'a> dot::Labeller<'a> for Edges {
68 //! fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example1").unwrap() }
70 //! fn node_id(&'a self, n: &Nd) -> dot::Id<'a> {
71 //! dot::Id::new(format!("N{}", *n)).unwrap()
75 //! impl<'a> dot::GraphWalk<'a> for Edges {
78 //! fn nodes(&self) -> dot::Nodes<'a,Nd> {
79 //! // (assumes that |N| \approxeq |E|)
80 //! let &Edges(ref v) = self;
81 //! let mut nodes = Vec::with_capacity(v.len());
83 //! nodes.push(s); nodes.push(t);
90 //! fn edges(&'a self) -> dot::Edges<'a,Ed> {
91 //! let &Edges(ref edges) = self;
92 //! (&edges[..]).into_cow()
95 //! fn source(&self, e: &Ed) -> Nd { let &(s,_) = e; s }
97 //! fn target(&self, e: &Ed) -> Nd { let &(_,t) = e; t }
100 //! # pub fn main() { render_to(&mut Vec::new()) }
104 //! # pub fn render_to<W:std::io::Write>(output: &mut W) { unimplemented!() }
106 //! use std::fs::File;
107 //! let mut f = File::create("example1.dot").unwrap();
108 //! render_to(&mut f)
112 //! Output from first example (in `example1.dot`):
115 //! digraph example1 {
121 //! N0 -> N1[label=""];
122 //! N0 -> N2[label=""];
123 //! N1 -> N3[label=""];
124 //! N2 -> N3[label=""];
125 //! N3 -> N4[label=""];
126 //! N4 -> N4[label=""];
130 //! The second example illustrates using `node_label` and `edge_label` to
131 //! add labels to the nodes and edges in the rendered graph. The graph
132 //! here carries both `nodes` (the label text to use for rendering a
133 //! particular node), and `edges` (again a list of `(source,target)`
136 //! This example also illustrates how to use a type (in this case the edge
137 //! type) that shares substructure with the graph: the edge type here is a
138 //! direct reference to the `(source,target)` pair stored in the graph's
139 //! internal vector (rather than passing around a copy of the pair
140 //! itself). Note that this implies that `fn edges(&'a self)` must
141 //! construct a fresh `Vec<&'a (usize,usize)>` from the `Vec<(usize,usize)>`
142 //! edges stored in `self`.
144 //! Since both the set of nodes and the set of edges are always
145 //! constructed from scratch via iterators, we use the `collect()` method
146 //! from the `Iterator` trait to collect the nodes and edges into freshly
147 //! constructed growable `Vec` values (rather use the `into_cow`
148 //! from the `IntoCow` trait as was used in the first example
151 //! The output from this example renders four nodes that make up the
152 //! Hasse-diagram for the subsets of the set `{x, y}`. Each edge is
153 //! labelled with the ⊆ character (specified using the HTML character
157 //! #![feature(rustc_private)]
159 //! use std::io::Write;
160 //! use graphviz as dot;
163 //! type Ed<'a> = &'a (usize, usize);
164 //! struct Graph { nodes: Vec<&'static str>, edges: Vec<(usize,usize)> }
166 //! pub fn render_to<W: Write>(output: &mut W) {
167 //! let nodes = vec!["{x,y}","{x}","{y}","{}"];
168 //! let edges = vec![(0,1), (0,2), (1,3), (2,3)];
169 //! let graph = Graph { nodes: nodes, edges: edges };
171 //! dot::render(&graph, output).unwrap()
174 //! impl<'a> dot::Labeller<'a> for Graph {
176 //! type Edge = Ed<'a>;
177 //! fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example2").unwrap() }
178 //! fn node_id(&'a self, n: &Nd) -> dot::Id<'a> {
179 //! dot::Id::new(format!("N{}", n)).unwrap()
181 //! fn node_label<'b>(&'b self, n: &Nd) -> dot::LabelText<'b> {
182 //! dot::LabelText::LabelStr(self.nodes[*n].into())
184 //! fn edge_label<'b>(&'b self, _: &Ed) -> dot::LabelText<'b> {
185 //! dot::LabelText::LabelStr("⊆".into())
189 //! impl<'a> dot::GraphWalk<'a> for Graph {
191 //! type Edge = Ed<'a>;
192 //! fn nodes(&self) -> dot::Nodes<'a,Nd> { (0..self.nodes.len()).collect() }
193 //! fn edges(&'a self) -> dot::Edges<'a,Ed<'a>> { self.edges.iter().collect() }
194 //! fn source(&self, e: &Ed) -> Nd { let & &(s,_) = e; s }
195 //! fn target(&self, e: &Ed) -> Nd { let & &(_,t) = e; t }
198 //! # pub fn main() { render_to(&mut Vec::new()) }
202 //! # pub fn render_to<W:std::io::Write>(output: &mut W) { unimplemented!() }
204 //! use std::fs::File;
205 //! let mut f = File::create("example2.dot").unwrap();
206 //! render_to(&mut f)
210 //! The third example is similar to the second, except now each node and
211 //! edge now carries a reference to the string label for each node as well
212 //! as that node's index. (This is another illustration of how to share
213 //! structure with the graph itself, and why one might want to do so.)
215 //! The output from this example is the same as the second example: the
216 //! Hasse-diagram for the subsets of the set `{x, y}`.
219 //! #![feature(rustc_private)]
221 //! use std::io::Write;
222 //! use graphviz as dot;
224 //! type Nd<'a> = (usize, &'a str);
225 //! type Ed<'a> = (Nd<'a>, Nd<'a>);
226 //! struct Graph { nodes: Vec<&'static str>, edges: Vec<(usize,usize)> }
228 //! pub fn render_to<W: Write>(output: &mut W) {
229 //! let nodes = vec!["{x,y}","{x}","{y}","{}"];
230 //! let edges = vec![(0,1), (0,2), (1,3), (2,3)];
231 //! let graph = Graph { nodes: nodes, edges: edges };
233 //! dot::render(&graph, output).unwrap()
236 //! impl<'a> dot::Labeller<'a> for Graph {
237 //! type Node = Nd<'a>;
238 //! type Edge = Ed<'a>;
239 //! fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example3").unwrap() }
240 //! fn node_id(&'a self, n: &Nd<'a>) -> dot::Id<'a> {
241 //! dot::Id::new(format!("N{}", n.0)).unwrap()
243 //! fn node_label<'b>(&'b self, n: &Nd<'b>) -> dot::LabelText<'b> {
245 //! dot::LabelText::LabelStr(self.nodes[i].into())
247 //! fn edge_label<'b>(&'b self, _: &Ed<'b>) -> dot::LabelText<'b> {
248 //! dot::LabelText::LabelStr("⊆".into())
252 //! impl<'a> dot::GraphWalk<'a> for Graph {
253 //! type Node = Nd<'a>;
254 //! type Edge = Ed<'a>;
255 //! fn nodes(&'a self) -> dot::Nodes<'a,Nd<'a>> {
256 //! self.nodes.iter().map(|s| &s[..]).enumerate().collect()
258 //! fn edges(&'a self) -> dot::Edges<'a,Ed<'a>> {
259 //! self.edges.iter()
260 //! .map(|&(i,j)|((i, &self.nodes[i][..]),
261 //! (j, &self.nodes[j][..])))
264 //! fn source(&self, e: &Ed<'a>) -> Nd<'a> { let &(s,_) = e; s }
265 //! fn target(&self, e: &Ed<'a>) -> Nd<'a> { let &(_,t) = e; t }
268 //! # pub fn main() { render_to(&mut Vec::new()) }
272 //! # pub fn render_to<W:std::io::Write>(output: &mut W) { unimplemented!() }
274 //! use std::fs::File;
275 //! let mut f = File::create("example3.dot").unwrap();
276 //! render_to(&mut f)
282 //! * [Graphviz](http://www.graphviz.org/)
284 //! * [DOT language](http://www.graphviz.org/doc/info/lang.html)
286 #![crate_name = "graphviz"]
287 #![unstable(feature = "rustc_private", issue = "27812")]
288 #![feature(staged_api)]
289 #![crate_type = "rlib"]
290 #![crate_type = "dylib"]
291 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
292 html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
293 html_root_url = "https://doc.rust-lang.org/nightly/",
294 test(attr(allow(unused_variables), deny(warnings))))]
295 #![cfg_attr(not(stage0), deny(warnings))]
297 #![feature(str_escape)]
298 #![cfg_attr(stage0, feature(question_mark))]
300 use self::LabelText::*;
302 use std::borrow::{Cow, ToOwned};
303 use std::io::prelude::*;
306 /// The text for a graphviz label on a node or edge.
307 pub enum LabelText<'a> {
308 /// This kind of label preserves the text directly as is.
310 /// Occurrences of backslashes (`\`) are escaped, and thus appear
311 /// as backslashes in the rendered label.
312 LabelStr(Cow<'a, str>),
314 /// This kind of label uses the graphviz label escString type:
315 /// http://www.graphviz.org/content/attrs#kescString
317 /// Occurrences of backslashes (`\`) are not escaped; instead they
318 /// are interpreted as initiating an escString escape sequence.
320 /// Escape sequences of particular interest: in addition to `\n`
321 /// to break a line (centering the line preceding the `\n`), there
322 /// are also the escape sequences `\l` which left-justifies the
323 /// preceding line and `\r` which right-justifies it.
324 EscStr(Cow<'a, str>),
326 /// This uses a graphviz [HTML string label][html]. The string is
327 /// printed exactly as given, but between `<` and `>`. **No
328 /// escaping is performed.**
330 /// [html]: http://www.graphviz.org/content/node-shapes#html
331 HtmlStr(Cow<'a, str>),
334 /// The style for a node or edge.
335 /// See http://www.graphviz.org/doc/info/attrs.html#k:style for descriptions.
336 /// Note that some of these are not valid for edges.
337 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
352 pub fn as_slice(self) -> &'static str {
355 Style::Solid => "solid",
356 Style::Dashed => "dashed",
357 Style::Dotted => "dotted",
358 Style::Bold => "bold",
359 Style::Rounded => "rounded",
360 Style::Diagonals => "diagonals",
361 Style::Filled => "filled",
362 Style::Striped => "striped",
363 Style::Wedged => "wedged",
368 // There is a tension in the design of the labelling API.
370 // For example, I considered making a `Labeller<T>` trait that
371 // provides labels for `T`, and then making the graph type `G`
372 // implement `Labeller<Node>` and `Labeller<Edge>`. However, this is
373 // not possible without functional dependencies. (One could work
374 // around that, but I did not explore that avenue heavily.)
376 // Another approach that I actually used for a while was to make a
377 // `Label<Context>` trait that is implemented by the client-specific
378 // Node and Edge types (as well as an implementation on Graph itself
379 // for the overall name for the graph). The main disadvantage of this
380 // second approach (compared to having the `G` type parameter
381 // implement a Labelling service) that I have encountered is that it
382 // makes it impossible to use types outside of the current crate
383 // directly as Nodes/Edges; you need to wrap them in newtype'd
384 // structs. See e.g. the `No` and `Ed` structs in the examples. (In
385 // practice clients using a graph in some other crate would need to
386 // provide some sort of adapter shim over the graph anyway to
387 // interface with this library).
389 // Another approach would be to make a single `Labeller<N,E>` trait
390 // that provides three methods (graph_label, node_label, edge_label),
391 // and then make `G` implement `Labeller<N,E>`. At first this did not
392 // appeal to me, since I had thought I would need separate methods on
393 // each data variant for dot-internal identifiers versus user-visible
394 // labels. However, the identifier/label distinction only arises for
395 // nodes; graphs themselves only have identifiers, and edges only have
398 // So in the end I decided to use the third approach described above.
400 /// `Id` is a Graphviz `ID`.
406 /// Creates an `Id` named `name`.
408 /// The caller must ensure that the input conforms to an
409 /// identifier format: it must be a non-empty string made up of
410 /// alphanumeric or underscore characters, not beginning with a
411 /// digit (i.e. the regular expression `[a-zA-Z_][a-zA-Z_0-9]*`).
413 /// (Note: this format is a strict subset of the `ID` format
414 /// defined by the DOT language. This function may change in the
415 /// future to accept a broader subset, or the entirety, of DOT's
418 /// Passing an invalid string (containing spaces, brackets,
419 /// quotes, ...) will return an empty `Err` value.
420 pub fn new<Name: IntoCow<'a, str>>(name: Name) -> Result<Id<'a>, ()> {
421 let name = name.into_cow();
423 let mut chars = name.chars();
425 Some(c) if is_letter_or_underscore(c) => {}
428 if !chars.all(is_constituent) {
432 return Ok(Id { name: name });
434 fn is_letter_or_underscore(c: char) -> bool {
435 in_range('a', c, 'z') || in_range('A', c, 'Z') || c == '_'
437 fn is_constituent(c: char) -> bool {
438 is_letter_or_underscore(c) || in_range('0', c, '9')
440 fn in_range(low: char, c: char, high: char) -> bool {
441 low as usize <= c as usize && c as usize <= high as usize
445 pub fn as_slice(&'a self) -> &'a str {
449 pub fn name(self) -> Cow<'a, str> {
454 /// Each instance of a type that implements `Label<C>` maps to a
455 /// unique identifier with respect to `C`, which is used to identify
456 /// it in the generated .dot file. They can also provide more
457 /// elaborate (and non-unique) label text that is used in the graphviz
460 /// The graph instance is responsible for providing the DOT compatible
461 /// identifiers for the nodes and (optionally) rendered labels for the nodes and
462 /// edges, as well as an identifier for the graph itself.
463 pub trait Labeller<'a> {
467 /// Must return a DOT compatible identifier naming the graph.
468 fn graph_id(&'a self) -> Id<'a>;
470 /// Maps `n` to a unique identifier with respect to `self`. The
471 /// implementor is responsible for ensuring that the returned name
472 /// is a valid DOT identifier.
473 fn node_id(&'a self, n: &Self::Node) -> Id<'a>;
475 /// Maps `n` to one of the [graphviz `shape` names][1]. If `None`
476 /// is returned, no `shape` attribute is specified.
478 /// [1]: http://www.graphviz.org/content/node-shapes
479 fn node_shape(&'a self, _node: &Self::Node) -> Option<LabelText<'a>> {
483 /// Maps `n` to a label that will be used in the rendered output.
484 /// The label need not be unique, and may be the empty string; the
485 /// default is just the output from `node_id`.
486 fn node_label(&'a self, n: &Self::Node) -> LabelText<'a> {
487 LabelStr(self.node_id(n).name)
490 /// Maps `e` to a label that will be used in the rendered output.
491 /// The label need not be unique, and may be the empty string; the
492 /// default is in fact the empty string.
493 fn edge_label(&'a self, e: &Self::Edge) -> LabelText<'a> {
495 LabelStr("".into_cow())
498 /// Maps `n` to a style that will be used in the rendered output.
499 fn node_style(&'a self, _n: &Self::Node) -> Style {
503 /// Maps `e` to a style that will be used in the rendered output.
504 fn edge_style(&'a self, _e: &Self::Edge) -> Style {
509 /// Escape tags in such a way that it is suitable for inclusion in a
510 /// Graphviz HTML label.
511 pub fn escape_html(s: &str) -> String {
512 s.replace("&", "&")
513 .replace("\"", """)
514 .replace("<", "<")
515 .replace(">", ">")
518 impl<'a> LabelText<'a> {
519 pub fn label<S: IntoCow<'a, str>>(s: S) -> LabelText<'a> {
520 LabelStr(s.into_cow())
523 pub fn escaped<S: IntoCow<'a, str>>(s: S) -> LabelText<'a> {
527 pub fn html<S: IntoCow<'a, str>>(s: S) -> LabelText<'a> {
528 HtmlStr(s.into_cow())
531 fn escape_char<F>(c: char, mut f: F)
535 // not escaping \\, since Graphviz escString needs to
536 // interpret backslashes; see EscStr above.
539 for c in c.escape_default() {
545 fn escape_str(s: &str) -> String {
546 let mut out = String::with_capacity(s.len());
548 LabelText::escape_char(c, |c| out.push(c));
553 /// Renders text as string suitable for a label in a .dot file.
554 /// This includes quotes or suitable delimeters.
555 pub fn to_dot_string(&self) -> String {
557 &LabelStr(ref s) => format!("\"{}\"", s.escape_default()),
558 &EscStr(ref s) => format!("\"{}\"", LabelText::escape_str(&s[..])),
559 &HtmlStr(ref s) => format!("<{}>", s),
563 /// Decomposes content into string suitable for making EscStr that
564 /// yields same content as self. The result obeys the law
565 /// render(`lt`) == render(`EscStr(lt.pre_escaped_content())`) for
566 /// all `lt: LabelText`.
567 fn pre_escaped_content(self) -> Cow<'a, str> {
571 if s.contains('\\') {
572 (&*s).escape_default().into_cow()
581 /// Puts `prefix` on a line above this label, with a blank line separator.
582 pub fn prefix_line(self, prefix: LabelText) -> LabelText<'static> {
583 prefix.suffix_line(self)
586 /// Puts `suffix` on a line below this label, with a blank line separator.
587 pub fn suffix_line(self, suffix: LabelText) -> LabelText<'static> {
588 let mut prefix = self.pre_escaped_content().into_owned();
589 let suffix = suffix.pre_escaped_content();
590 prefix.push_str(r"\n\n");
591 prefix.push_str(&suffix[..]);
592 EscStr(prefix.into_cow())
596 pub type Nodes<'a,N> = Cow<'a,[N]>;
597 pub type Edges<'a,E> = Cow<'a,[E]>;
599 // (The type parameters in GraphWalk should be associated items,
600 // when/if Rust supports such.)
602 /// GraphWalk is an abstraction over a directed graph = (nodes,edges)
603 /// made up of node handles `N` and edge handles `E`, where each `E`
604 /// can be mapped to its source and target nodes.
606 /// The lifetime parameter `'a` is exposed in this trait (rather than
607 /// introduced as a generic parameter on each method declaration) so
608 /// that a client impl can choose `N` and `E` that have substructure
609 /// that is bound by the self lifetime `'a`.
611 /// The `nodes` and `edges` method each return instantiations of
612 /// `Cow<[T]>` to leave implementors the freedom to create
613 /// entirely new vectors or to pass back slices into internally owned
615 pub trait GraphWalk<'a> {
619 /// Returns all the nodes in this graph.
620 fn nodes(&'a self) -> Nodes<'a, Self::Node>;
621 /// Returns all of the edges in this graph.
622 fn edges(&'a self) -> Edges<'a, Self::Edge>;
623 /// The source node for `edge`.
624 fn source(&'a self, edge: &Self::Edge) -> Self::Node;
625 /// The target node for `edge`.
626 fn target(&'a self, edge: &Self::Edge) -> Self::Node;
629 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
630 pub enum RenderOption {
637 /// Returns vec holding all the default render options.
638 pub fn default_options() -> Vec<RenderOption> {
642 /// Renders directed graph `g` into the writer `w` in DOT syntax.
643 /// (Simple wrapper around `render_opts` that passes a default set of options.)
644 pub fn render<'a,N,E,G,W>(g: &'a G, w: &mut W) -> io::Result<()>
647 G: Labeller<'a, Node=N, Edge=E> + GraphWalk<'a, Node=N, Edge=E>,
650 render_opts(g, w, &[])
653 /// Renders directed graph `g` into the writer `w` in DOT syntax.
654 /// (Main entry point for the library.)
655 pub fn render_opts<'a, N, E, G, W>(g: &'a G,
657 options: &[RenderOption])
661 G: Labeller<'a, Node=N, Edge=E> + GraphWalk<'a, Node=N, Edge=E>,
664 fn writeln<W: Write>(w: &mut W, arg: &[&str]) -> io::Result<()> {
666 w.write_all(s.as_bytes())?;
671 fn indent<W: Write>(w: &mut W) -> io::Result<()> {
675 writeln(w, &["digraph ", g.graph_id().as_slice(), " {"])?;
676 for n in g.nodes().iter() {
678 let id = g.node_id(n);
680 let escaped = &g.node_label(n).to_dot_string();
683 let mut text = vec![id.as_slice()];
685 if !options.contains(&RenderOption::NoNodeLabels) {
686 text.push("[label=");
691 let style = g.node_style(n);
692 if !options.contains(&RenderOption::NoNodeStyles) && style != Style::None {
693 text.push("[style=\"");
694 text.push(style.as_slice());
698 if let Some(s) = g.node_shape(n) {
699 shape = s.to_dot_string();
700 text.push("[shape=");
709 for e in g.edges().iter() {
710 let escaped_label = &g.edge_label(e).to_dot_string();
712 let source = g.source(e);
713 let target = g.target(e);
714 let source_id = g.node_id(&source);
715 let target_id = g.node_id(&target);
717 let mut text = vec![source_id.as_slice(), " -> ", target_id.as_slice()];
719 if !options.contains(&RenderOption::NoEdgeLabels) {
720 text.push("[label=");
721 text.push(escaped_label);
725 let style = g.edge_style(e);
726 if !options.contains(&RenderOption::NoEdgeStyles) && style != Style::None {
727 text.push("[style=\"");
728 text.push(style.as_slice());
739 pub trait IntoCow<'a, B: ?Sized> where B: ToOwned {
740 fn into_cow(self) -> Cow<'a, B>;
743 impl<'a> IntoCow<'a, str> for String {
744 fn into_cow(self) -> Cow<'a, str> {
749 impl<'a> IntoCow<'a, str> for &'a str {
750 fn into_cow(self) -> Cow<'a, str> {
755 impl<'a, T: Clone> IntoCow<'a, [T]> for Vec<T> {
756 fn into_cow(self) -> Cow<'a, [T]> {
761 impl<'a, T: Clone> IntoCow<'a, [T]> for &'a [T] {
762 fn into_cow(self) -> Cow<'a, [T]> {
769 use self::NodeLabels::*;
770 use super::{Id, Labeller, Nodes, Edges, GraphWalk, render, Style};
771 use super::LabelText::{self, LabelStr, EscStr, HtmlStr};
773 use std::io::prelude::*;
776 /// each node is an index in a vector in the graph.
785 fn edge(from: usize, to: usize, label: &'static str, style: Style) -> Edge {
794 struct LabelledGraph {
795 /// The name for this graph. Used for labelling generated `digraph`.
798 /// Each node is an index into `node_labels`; these labels are
799 /// used as the label text for each node. (The node *names*,
800 /// which are unique identifiers, are derived from their index
803 /// If a node maps to None here, then just use its name as its
805 node_labels: Vec<Option<&'static str>>,
807 node_styles: Vec<Style>,
809 /// Each edge relates a from-index to a to-index along with a
810 /// label; `edges` collects them.
814 // A simple wrapper around LabelledGraph that forces the labels to
815 // be emitted as EscStr.
816 struct LabelledGraphWithEscStrs {
817 graph: LabelledGraph,
821 AllNodesLabelled(Vec<L>),
822 UnlabelledNodes(usize),
823 SomeNodesLabelled(Vec<Option<L>>),
826 type Trivial = NodeLabels<&'static str>;
828 impl NodeLabels<&'static str> {
829 fn to_opt_strs(self) -> Vec<Option<&'static str>> {
831 UnlabelledNodes(len) => vec![None; len],
832 AllNodesLabelled(lbls) => lbls.into_iter().map(|l| Some(l)).collect(),
833 SomeNodesLabelled(lbls) => lbls.into_iter().collect(),
837 fn len(&self) -> usize {
839 &UnlabelledNodes(len) => len,
840 &AllNodesLabelled(ref lbls) => lbls.len(),
841 &SomeNodesLabelled(ref lbls) => lbls.len(),
847 fn new(name: &'static str,
848 node_labels: Trivial,
850 node_styles: Option<Vec<Style>>)
852 let count = node_labels.len();
855 node_labels: node_labels.to_opt_strs(),
857 node_styles: match node_styles {
858 Some(nodes) => nodes,
859 None => vec![Style::None; count],
865 impl LabelledGraphWithEscStrs {
866 fn new(name: &'static str,
867 node_labels: Trivial,
869 -> LabelledGraphWithEscStrs {
870 LabelledGraphWithEscStrs { graph: LabelledGraph::new(name, node_labels, edges, None) }
874 fn id_name<'a>(n: &Node) -> Id<'a> {
875 Id::new(format!("N{}", *n)).unwrap()
878 impl<'a> Labeller<'a> for LabelledGraph {
880 type Edge = &'a Edge;
881 fn graph_id(&'a self) -> Id<'a> {
882 Id::new(&self.name[..]).unwrap()
884 fn node_id(&'a self, n: &Node) -> Id<'a> {
887 fn node_label(&'a self, n: &Node) -> LabelText<'a> {
888 match self.node_labels[*n] {
889 Some(ref l) => LabelStr(l.into_cow()),
890 None => LabelStr(id_name(n).name()),
893 fn edge_label(&'a self, e: &&'a Edge) -> LabelText<'a> {
894 LabelStr(e.label.into_cow())
896 fn node_style(&'a self, n: &Node) -> Style {
899 fn edge_style(&'a self, e: &&'a Edge) -> Style {
904 impl<'a> Labeller<'a> for LabelledGraphWithEscStrs {
906 type Edge = &'a Edge;
907 fn graph_id(&'a self) -> Id<'a> {
908 self.graph.graph_id()
910 fn node_id(&'a self, n: &Node) -> Id<'a> {
911 self.graph.node_id(n)
913 fn node_label(&'a self, n: &Node) -> LabelText<'a> {
914 match self.graph.node_label(n) {
915 LabelStr(s) | EscStr(s) | HtmlStr(s) => EscStr(s),
918 fn edge_label(&'a self, e: &&'a Edge) -> LabelText<'a> {
919 match self.graph.edge_label(e) {
920 LabelStr(s) | EscStr(s) | HtmlStr(s) => EscStr(s),
925 impl<'a> GraphWalk<'a> for LabelledGraph {
927 type Edge = &'a Edge;
928 fn nodes(&'a self) -> Nodes<'a, Node> {
929 (0..self.node_labels.len()).collect()
931 fn edges(&'a self) -> Edges<'a, &'a Edge> {
932 self.edges.iter().collect()
934 fn source(&'a self, edge: &&'a Edge) -> Node {
937 fn target(&'a self, edge: &&'a Edge) -> Node {
942 impl<'a> GraphWalk<'a> for LabelledGraphWithEscStrs {
944 type Edge = &'a Edge;
945 fn nodes(&'a self) -> Nodes<'a, Node> {
948 fn edges(&'a self) -> Edges<'a, &'a Edge> {
951 fn source(&'a self, edge: &&'a Edge) -> Node {
954 fn target(&'a self, edge: &&'a Edge) -> Node {
959 fn test_input(g: LabelledGraph) -> io::Result<String> {
960 let mut writer = Vec::new();
961 render(&g, &mut writer).unwrap();
962 let mut s = String::new();
963 Read::read_to_string(&mut &*writer, &mut s)?;
967 // All of the tests use raw-strings as the format for the expected outputs,
968 // so that you can cut-and-paste the content into a .dot file yourself to
969 // see what the graphviz visualizer would produce.
973 let labels: Trivial = UnlabelledNodes(0);
974 let r = test_input(LabelledGraph::new("empty_graph", labels, vec![], None));
975 assert_eq!(r.unwrap(),
976 r#"digraph empty_graph {
983 let labels: Trivial = UnlabelledNodes(1);
984 let r = test_input(LabelledGraph::new("single_node", labels, vec![], None));
985 assert_eq!(r.unwrap(),
986 r#"digraph single_node {
993 fn single_node_with_style() {
994 let labels: Trivial = UnlabelledNodes(1);
995 let styles = Some(vec![Style::Dashed]);
996 let r = test_input(LabelledGraph::new("single_node", labels, vec![], styles));
997 assert_eq!(r.unwrap(),
998 r#"digraph single_node {
999 N0[label="N0"][style="dashed"];
1006 let labels: Trivial = UnlabelledNodes(2);
1007 let result = test_input(LabelledGraph::new("single_edge",
1009 vec![edge(0, 1, "E", Style::None)],
1011 assert_eq!(result.unwrap(),
1012 r#"digraph single_edge {
1015 N0 -> N1[label="E"];
1021 fn single_edge_with_style() {
1022 let labels: Trivial = UnlabelledNodes(2);
1023 let result = test_input(LabelledGraph::new("single_edge",
1025 vec![edge(0, 1, "E", Style::Bold)],
1027 assert_eq!(result.unwrap(),
1028 r#"digraph single_edge {
1031 N0 -> N1[label="E"][style="bold"];
1037 fn test_some_labelled() {
1038 let labels: Trivial = SomeNodesLabelled(vec![Some("A"), None]);
1039 let styles = Some(vec![Style::None, Style::Dotted]);
1040 let result = test_input(LabelledGraph::new("test_some_labelled",
1042 vec![edge(0, 1, "A-1", Style::None)],
1044 assert_eq!(result.unwrap(),
1045 r#"digraph test_some_labelled {
1047 N1[label="N1"][style="dotted"];
1048 N0 -> N1[label="A-1"];
1054 fn single_cyclic_node() {
1055 let labels: Trivial = UnlabelledNodes(1);
1056 let r = test_input(LabelledGraph::new("single_cyclic_node",
1058 vec![edge(0, 0, "E", Style::None)],
1060 assert_eq!(r.unwrap(),
1061 r#"digraph single_cyclic_node {
1063 N0 -> N0[label="E"];
1069 fn hasse_diagram() {
1070 let labels = AllNodesLabelled(vec!["{x,y}", "{x}", "{y}", "{}"]);
1071 let r = test_input(LabelledGraph::new("hasse_diagram",
1073 vec![edge(0, 1, "", Style::None),
1074 edge(0, 2, "", Style::None),
1075 edge(1, 3, "", Style::None),
1076 edge(2, 3, "", Style::None)],
1078 assert_eq!(r.unwrap(),
1079 r#"digraph hasse_diagram {
1093 fn left_aligned_text() {
1094 let labels = AllNodesLabelled(vec![
1106 let mut writer = Vec::new();
1108 let g = LabelledGraphWithEscStrs::new("syntax_tree",
1110 vec![edge(0, 1, "then", Style::None),
1111 edge(0, 2, "else", Style::None),
1112 edge(1, 3, ";", Style::None),
1113 edge(2, 3, ";", Style::None)]);
1115 render(&g, &mut writer).unwrap();
1116 let mut r = String::new();
1117 Read::read_to_string(&mut &*writer, &mut r).unwrap();
1120 r#"digraph syntax_tree {
1121 N0[label="if test {\l branch1\l} else {\l branch2\l}\lafterward\l"];
1122 N1[label="branch1"];
1123 N2[label="branch2"];
1124 N3[label="afterward"];
1125 N0 -> N1[label="then"];
1126 N0 -> N2[label="else"];
1127 N1 -> N3[label=";"];
1128 N2 -> N3[label=";"];
1134 fn simple_id_construction() {
1135 let id1 = Id::new("hello");
1138 Err(..) => panic!("'hello' is not a valid value for id anymore"),
1143 fn badly_formatted_id() {
1144 let id2 = Id::new("Weird { struct : ure } !!!");
1146 Ok(_) => panic!("graphviz id suddenly allows spaces, brackets and stuff"),