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, Nd, Ed> for Edges {
66 //! fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example1").unwrap() }
68 //! fn node_id(&'a self, n: &Nd) -> dot::Id<'a> {
69 //! dot::Id::new(format!("N{}", *n)).unwrap()
73 //! impl<'a> dot::GraphWalk<'a, Nd, Ed> for Edges {
74 //! fn nodes(&self) -> dot::Nodes<'a,Nd> {
75 //! // (assumes that |N| \approxeq |E|)
76 //! let &Edges(ref v) = self;
77 //! let mut nodes = Vec::with_capacity(v.len());
79 //! nodes.push(s); nodes.push(t);
86 //! fn edges(&'a self) -> dot::Edges<'a,Ed> {
87 //! let &Edges(ref edges) = self;
88 //! (&edges[..]).into_cow()
91 //! fn source(&self, e: &Ed) -> Nd { let &(s,_) = e; s }
93 //! fn target(&self, e: &Ed) -> Nd { let &(_,t) = e; t }
96 //! # pub fn main() { render_to(&mut Vec::new()) }
100 //! # pub fn render_to<W:std::io::Write>(output: &mut W) { unimplemented!() }
102 //! use std::fs::File;
103 //! let mut f = File::create("example1.dot").unwrap();
104 //! render_to(&mut f)
108 //! Output from first example (in `example1.dot`):
111 //! digraph example1 {
117 //! N0 -> N1[label=""];
118 //! N0 -> N2[label=""];
119 //! N1 -> N3[label=""];
120 //! N2 -> N3[label=""];
121 //! N3 -> N4[label=""];
122 //! N4 -> N4[label=""];
126 //! The second example illustrates using `node_label` and `edge_label` to
127 //! add labels to the nodes and edges in the rendered graph. The graph
128 //! here carries both `nodes` (the label text to use for rendering a
129 //! particular node), and `edges` (again a list of `(source,target)`
132 //! This example also illustrates how to use a type (in this case the edge
133 //! type) that shares substructure with the graph: the edge type here is a
134 //! direct reference to the `(source,target)` pair stored in the graph's
135 //! internal vector (rather than passing around a copy of the pair
136 //! itself). Note that this implies that `fn edges(&'a self)` must
137 //! construct a fresh `Vec<&'a (usize,usize)>` from the `Vec<(usize,usize)>`
138 //! edges stored in `self`.
140 //! Since both the set of nodes and the set of edges are always
141 //! constructed from scratch via iterators, we use the `collect()` method
142 //! from the `Iterator` trait to collect the nodes and edges into freshly
143 //! constructed growable `Vec` values (rather use the `into_cow`
144 //! from the `IntoCow` trait as was used in the first example
147 //! The output from this example renders four nodes that make up the
148 //! Hasse-diagram for the subsets of the set `{x, y}`. Each edge is
149 //! labelled with the ⊆ character (specified using the HTML character
153 //! #![feature(rustc_private)]
155 //! use std::io::Write;
156 //! use graphviz as dot;
159 //! type Ed<'a> = &'a (usize, usize);
160 //! struct Graph { nodes: Vec<&'static str>, edges: Vec<(usize,usize)> }
162 //! pub fn render_to<W: Write>(output: &mut W) {
163 //! let nodes = vec!("{x,y}","{x}","{y}","{}");
164 //! let edges = vec!((0,1), (0,2), (1,3), (2,3));
165 //! let graph = Graph { nodes: nodes, edges: edges };
167 //! dot::render(&graph, output).unwrap()
170 //! impl<'a> dot::Labeller<'a, Nd, Ed<'a>> for Graph {
171 //! fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example2").unwrap() }
172 //! fn node_id(&'a self, n: &Nd) -> dot::Id<'a> {
173 //! dot::Id::new(format!("N{}", n)).unwrap()
175 //! fn node_label<'b>(&'b self, n: &Nd) -> dot::LabelText<'b> {
176 //! dot::LabelText::LabelStr(self.nodes[*n].into())
178 //! fn edge_label<'b>(&'b self, _: &Ed) -> dot::LabelText<'b> {
179 //! dot::LabelText::LabelStr("⊆".into())
183 //! impl<'a> dot::GraphWalk<'a, Nd, Ed<'a>> for Graph {
184 //! fn nodes(&self) -> dot::Nodes<'a,Nd> { (0..self.nodes.len()).collect() }
185 //! fn edges(&'a self) -> dot::Edges<'a,Ed<'a>> { self.edges.iter().collect() }
186 //! fn source(&self, e: &Ed) -> Nd { let & &(s,_) = e; s }
187 //! fn target(&self, e: &Ed) -> Nd { let & &(_,t) = e; t }
190 //! # pub fn main() { render_to(&mut Vec::new()) }
194 //! # pub fn render_to<W:std::io::Write>(output: &mut W) { unimplemented!() }
196 //! use std::fs::File;
197 //! let mut f = File::create("example2.dot").unwrap();
198 //! render_to(&mut f)
202 //! The third example is similar to the second, except now each node and
203 //! edge now carries a reference to the string label for each node as well
204 //! as that node's index. (This is another illustration of how to share
205 //! structure with the graph itself, and why one might want to do so.)
207 //! The output from this example is the same as the second example: the
208 //! Hasse-diagram for the subsets of the set `{x, y}`.
211 //! #![feature(rustc_private)]
213 //! use std::io::Write;
214 //! use graphviz as dot;
216 //! type Nd<'a> = (usize, &'a str);
217 //! type Ed<'a> = (Nd<'a>, Nd<'a>);
218 //! struct Graph { nodes: Vec<&'static str>, edges: Vec<(usize,usize)> }
220 //! pub fn render_to<W: Write>(output: &mut W) {
221 //! let nodes = vec!("{x,y}","{x}","{y}","{}");
222 //! let edges = vec!((0,1), (0,2), (1,3), (2,3));
223 //! let graph = Graph { nodes: nodes, edges: edges };
225 //! dot::render(&graph, output).unwrap()
228 //! impl<'a> dot::Labeller<'a, Nd<'a>, Ed<'a>> for Graph {
229 //! fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example3").unwrap() }
230 //! fn node_id(&'a self, n: &Nd<'a>) -> dot::Id<'a> {
231 //! dot::Id::new(format!("N{}", n.0)).unwrap()
233 //! fn node_label<'b>(&'b self, n: &Nd<'b>) -> dot::LabelText<'b> {
235 //! dot::LabelText::LabelStr(self.nodes[i].into())
237 //! fn edge_label<'b>(&'b self, _: &Ed<'b>) -> dot::LabelText<'b> {
238 //! dot::LabelText::LabelStr("⊆".into())
242 //! impl<'a> dot::GraphWalk<'a, Nd<'a>, Ed<'a>> for Graph {
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 #![crate_name = "graphviz"]
275 #![unstable(feature = "rustc_private", issue = "27812")]
276 #![feature(staged_api)]
277 #![crate_type = "rlib"]
278 #![crate_type = "dylib"]
279 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
280 html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
281 html_root_url = "https://doc.rust-lang.org/nightly/",
282 test(attr(allow(unused_variables), deny(warnings))))]
284 #![feature(str_escape)]
286 use self::LabelText::*;
288 use std::borrow::{Cow, ToOwned};
289 use std::io::prelude::*;
292 /// The text for a graphviz label on a node or edge.
293 pub enum LabelText<'a> {
294 /// This kind of label preserves the text directly as is.
296 /// Occurrences of backslashes (`\`) are escaped, and thus appear
297 /// as backslashes in the rendered label.
298 LabelStr(Cow<'a, str>),
300 /// This kind of label uses the graphviz label escString type:
301 /// http://www.graphviz.org/content/attrs#kescString
303 /// Occurrences of backslashes (`\`) are not escaped; instead they
304 /// are interpreted as initiating an escString escape sequence.
306 /// Escape sequences of particular interest: in addition to `\n`
307 /// to break a line (centering the line preceding the `\n`), there
308 /// are also the escape sequences `\l` which left-justifies the
309 /// preceding line and `\r` which right-justifies it.
310 EscStr(Cow<'a, str>),
312 /// This uses a graphviz [HTML string label][html]. The string is
313 /// printed exactly as given, but between `<` and `>`. **No
314 /// escaping is performed.**
316 /// [html]: http://www.graphviz.org/content/node-shapes#html
317 HtmlStr(Cow<'a, str>),
320 /// The style for a node or edge.
321 /// See http://www.graphviz.org/doc/info/attrs.html#k:style for descriptions.
322 /// Note that some of these are not valid for edges.
323 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
338 pub fn as_slice(self) -> &'static str {
341 Style::Solid => "solid",
342 Style::Dashed => "dashed",
343 Style::Dotted => "dotted",
344 Style::Bold => "bold",
345 Style::Rounded => "rounded",
346 Style::Diagonals => "diagonals",
347 Style::Filled => "filled",
348 Style::Striped => "striped",
349 Style::Wedged => "wedged",
354 // There is a tension in the design of the labelling API.
356 // For example, I considered making a `Labeller<T>` trait that
357 // provides labels for `T`, and then making the graph type `G`
358 // implement `Labeller<Node>` and `Labeller<Edge>`. However, this is
359 // not possible without functional dependencies. (One could work
360 // around that, but I did not explore that avenue heavily.)
362 // Another approach that I actually used for a while was to make a
363 // `Label<Context>` trait that is implemented by the client-specific
364 // Node and Edge types (as well as an implementation on Graph itself
365 // for the overall name for the graph). The main disadvantage of this
366 // second approach (compared to having the `G` type parameter
367 // implement a Labelling service) that I have encountered is that it
368 // makes it impossible to use types outside of the current crate
369 // directly as Nodes/Edges; you need to wrap them in newtype'd
370 // structs. See e.g. the `No` and `Ed` structs in the examples. (In
371 // practice clients using a graph in some other crate would need to
372 // provide some sort of adapter shim over the graph anyway to
373 // interface with this library).
375 // Another approach would be to make a single `Labeller<N,E>` trait
376 // that provides three methods (graph_label, node_label, edge_label),
377 // and then make `G` implement `Labeller<N,E>`. At first this did not
378 // appeal to me, since I had thought I would need separate methods on
379 // each data variant for dot-internal identifiers versus user-visible
380 // labels. However, the identifier/label distinction only arises for
381 // nodes; graphs themselves only have identifiers, and edges only have
384 // So in the end I decided to use the third approach described above.
386 /// `Id` is a Graphviz `ID`.
392 /// Creates an `Id` named `name`.
394 /// The caller must ensure that the input conforms to an
395 /// identifier format: it must be a non-empty string made up of
396 /// alphanumeric or underscore characters, not beginning with a
397 /// digit (i.e. the regular expression `[a-zA-Z_][a-zA-Z_0-9]*`).
399 /// (Note: this format is a strict subset of the `ID` format
400 /// defined by the DOT language. This function may change in the
401 /// future to accept a broader subset, or the entirety, of DOT's
404 /// Passing an invalid string (containing spaces, brackets,
405 /// quotes, ...) will return an empty `Err` value.
406 pub fn new<Name: IntoCow<'a, str>>(name: Name) -> Result<Id<'a>, ()> {
407 let name = name.into_cow();
409 let mut chars = name.chars();
411 Some(c) if is_letter_or_underscore(c) => {}
414 if !chars.all(is_constituent) {
418 return Ok(Id { name: name });
420 fn is_letter_or_underscore(c: char) -> bool {
421 in_range('a', c, 'z') || in_range('A', c, 'Z') || c == '_'
423 fn is_constituent(c: char) -> bool {
424 is_letter_or_underscore(c) || in_range('0', c, '9')
426 fn in_range(low: char, c: char, high: char) -> bool {
427 low as usize <= c as usize && c as usize <= high as usize
431 pub fn as_slice(&'a self) -> &'a str {
435 pub fn name(self) -> Cow<'a, str> {
440 /// Each instance of a type that implements `Label<C>` maps to a
441 /// unique identifier with respect to `C`, which is used to identify
442 /// it in the generated .dot file. They can also provide more
443 /// elaborate (and non-unique) label text that is used in the graphviz
446 /// The graph instance is responsible for providing the DOT compatible
447 /// identifiers for the nodes and (optionally) rendered labels for the nodes and
448 /// edges, as well as an identifier for the graph itself.
449 pub trait Labeller<'a,N,E> {
450 /// Must return a DOT compatible identifier naming the graph.
451 fn graph_id(&'a self) -> Id<'a>;
453 /// Maps `n` to a unique identifier with respect to `self`. The
454 /// implementor is responsible for ensuring that the returned name
455 /// is a valid DOT identifier.
456 fn node_id(&'a self, n: &N) -> Id<'a>;
458 /// Maps `n` to one of the [graphviz `shape` names][1]. If `None`
459 /// is returned, no `shape` attribute is specified.
461 /// [1]: http://www.graphviz.org/content/node-shapes
462 fn node_shape(&'a self, _node: &N) -> Option<LabelText<'a>> {
466 /// Maps `n` to a label that will be used in the rendered output.
467 /// The label need not be unique, and may be the empty string; the
468 /// default is just the output from `node_id`.
469 fn node_label(&'a self, n: &N) -> LabelText<'a> {
470 LabelStr(self.node_id(n).name)
473 /// Maps `e` to a label that will be used in the rendered output.
474 /// The label need not be unique, and may be the empty string; the
475 /// default is in fact the empty string.
476 fn edge_label(&'a self, e: &E) -> LabelText<'a> {
478 LabelStr("".into_cow())
481 /// Maps `n` to a style that will be used in the rendered output.
482 fn node_style(&'a self, _n: &N) -> Style {
486 /// Maps `e` to a style that will be used in the rendered output.
487 fn edge_style(&'a self, _e: &E) -> Style {
492 /// Escape tags in such a way that it is suitable for inclusion in a
493 /// Graphviz HTML label.
494 pub fn escape_html(s: &str) -> String {
495 s.replace("&", "&")
496 .replace("\"", """)
497 .replace("<", "<")
498 .replace(">", ">")
501 impl<'a> LabelText<'a> {
502 pub fn label<S: IntoCow<'a, str>>(s: S) -> LabelText<'a> {
503 LabelStr(s.into_cow())
506 pub fn escaped<S: IntoCow<'a, str>>(s: S) -> LabelText<'a> {
510 pub fn html<S: IntoCow<'a, str>>(s: S) -> LabelText<'a> {
511 HtmlStr(s.into_cow())
514 fn escape_char<F>(c: char, mut f: F)
518 // not escaping \\, since Graphviz escString needs to
519 // interpret backslashes; see EscStr above.
522 for c in c.escape_default() {
528 fn escape_str(s: &str) -> String {
529 let mut out = String::with_capacity(s.len());
531 LabelText::escape_char(c, |c| out.push(c));
536 /// Renders text as string suitable for a label in a .dot file.
537 /// This includes quotes or suitable delimeters.
538 pub fn to_dot_string(&self) -> String {
540 &LabelStr(ref s) => format!("\"{}\"", s.escape_default()),
541 &EscStr(ref s) => format!("\"{}\"", LabelText::escape_str(&s[..])),
542 &HtmlStr(ref s) => format!("<{}>", s),
546 /// Decomposes content into string suitable for making EscStr that
547 /// yields same content as self. The result obeys the law
548 /// render(`lt`) == render(`EscStr(lt.pre_escaped_content())`) for
549 /// all `lt: LabelText`.
550 fn pre_escaped_content(self) -> Cow<'a, str> {
554 if s.contains('\\') {
555 (&*s).escape_default().into_cow()
564 /// Puts `prefix` on a line above this label, with a blank line separator.
565 pub fn prefix_line(self, prefix: LabelText) -> LabelText<'static> {
566 prefix.suffix_line(self)
569 /// Puts `suffix` on a line below this label, with a blank line separator.
570 pub fn suffix_line(self, suffix: LabelText) -> LabelText<'static> {
571 let mut prefix = self.pre_escaped_content().into_owned();
572 let suffix = suffix.pre_escaped_content();
573 prefix.push_str(r"\n\n");
574 prefix.push_str(&suffix[..]);
575 EscStr(prefix.into_cow())
579 pub type Nodes<'a,N> = Cow<'a,[N]>;
580 pub type Edges<'a,E> = Cow<'a,[E]>;
582 // (The type parameters in GraphWalk should be associated items,
583 // when/if Rust supports such.)
585 /// GraphWalk is an abstraction over a directed graph = (nodes,edges)
586 /// made up of node handles `N` and edge handles `E`, where each `E`
587 /// can be mapped to its source and target nodes.
589 /// The lifetime parameter `'a` is exposed in this trait (rather than
590 /// introduced as a generic parameter on each method declaration) so
591 /// that a client impl can choose `N` and `E` that have substructure
592 /// that is bound by the self lifetime `'a`.
594 /// The `nodes` and `edges` method each return instantiations of
595 /// `Cow<[T]>` to leave implementors the freedom to create
596 /// entirely new vectors or to pass back slices into internally owned
598 pub trait GraphWalk<'a, N: Clone, E: Clone> {
599 /// Returns all the nodes in this graph.
600 fn nodes(&'a self) -> Nodes<'a, N>;
601 /// Returns all of the edges in this graph.
602 fn edges(&'a self) -> Edges<'a, E>;
603 /// The source node for `edge`.
604 fn source(&'a self, edge: &E) -> N;
605 /// The target node for `edge`.
606 fn target(&'a self, edge: &E) -> N;
609 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
610 pub enum RenderOption {
617 /// Returns vec holding all the default render options.
618 pub fn default_options() -> Vec<RenderOption> {
622 /// Renders directed graph `g` into the writer `w` in DOT syntax.
623 /// (Simple wrapper around `render_opts` that passes a default set of options.)
627 G: Labeller<'a, N, E> + GraphWalk<'a, N, E>,
632 render_opts(g, w, &[])
635 /// Renders directed graph `g` into the writer `w` in DOT syntax.
636 /// (Main entry point for the library.)
637 pub fn render_opts<'a,
640 G: Labeller<'a, N, E> + GraphWalk<'a, N, E>,
644 options: &[RenderOption])
646 fn writeln<W: Write>(w: &mut W, arg: &[&str]) -> io::Result<()> {
648 try!(w.write_all(s.as_bytes()));
653 fn indent<W: Write>(w: &mut W) -> io::Result<()> {
657 try!(writeln(w, &["digraph ", g.graph_id().as_slice(), " {"]));
658 for n in g.nodes().iter() {
660 let id = g.node_id(n);
662 let escaped = &g.node_label(n).to_dot_string();
665 let mut text = vec![id.as_slice()];
667 if !options.contains(&RenderOption::NoNodeLabels) {
668 text.push("[label=");
673 let style = g.node_style(n);
674 if !options.contains(&RenderOption::NoNodeStyles) && style != Style::None {
675 text.push("[style=\"");
676 text.push(style.as_slice());
680 if let Some(s) = g.node_shape(n) {
681 shape = s.to_dot_string();
682 text.push("[shape=");
688 try!(writeln(w, &text));
691 for e in g.edges().iter() {
692 let escaped_label = &g.edge_label(e).to_dot_string();
694 let source = g.source(e);
695 let target = g.target(e);
696 let source_id = g.node_id(&source);
697 let target_id = g.node_id(&target);
699 let mut text = vec![source_id.as_slice(), " -> ", target_id.as_slice()];
701 if !options.contains(&RenderOption::NoEdgeLabels) {
702 text.push("[label=");
703 text.push(escaped_label);
707 let style = g.edge_style(e);
708 if !options.contains(&RenderOption::NoEdgeStyles) && style != Style::None {
709 text.push("[style=\"");
710 text.push(style.as_slice());
715 try!(writeln(w, &text));
721 pub trait IntoCow<'a, B: ?Sized> where B: ToOwned {
722 fn into_cow(self) -> Cow<'a, B>;
725 impl<'a> IntoCow<'a, str> for String {
726 fn into_cow(self) -> Cow<'a, str> {
731 impl<'a> IntoCow<'a, str> for &'a str {
732 fn into_cow(self) -> Cow<'a, str> {
737 impl<'a, T: Clone> IntoCow<'a, [T]> for Vec<T> {
738 fn into_cow(self) -> Cow<'a, [T]> {
743 impl<'a, T: Clone> IntoCow<'a, [T]> for &'a [T] {
744 fn into_cow(self) -> Cow<'a, [T]> {
751 use self::NodeLabels::*;
752 use super::{Id, Labeller, Nodes, Edges, GraphWalk, render, Style};
753 use super::LabelText::{self, LabelStr, EscStr, HtmlStr};
755 use std::io::prelude::*;
758 /// each node is an index in a vector in the graph.
767 fn edge(from: usize, to: usize, label: &'static str, style: Style) -> Edge {
776 struct LabelledGraph {
777 /// The name for this graph. Used for labelling generated `digraph`.
780 /// Each node is an index into `node_labels`; these labels are
781 /// used as the label text for each node. (The node *names*,
782 /// which are unique identifiers, are derived from their index
785 /// If a node maps to None here, then just use its name as its
787 node_labels: Vec<Option<&'static str>>,
789 node_styles: Vec<Style>,
791 /// Each edge relates a from-index to a to-index along with a
792 /// label; `edges` collects them.
796 // A simple wrapper around LabelledGraph that forces the labels to
797 // be emitted as EscStr.
798 struct LabelledGraphWithEscStrs {
799 graph: LabelledGraph,
803 AllNodesLabelled(Vec<L>),
804 UnlabelledNodes(usize),
805 SomeNodesLabelled(Vec<Option<L>>),
808 type Trivial = NodeLabels<&'static str>;
810 impl NodeLabels<&'static str> {
811 fn to_opt_strs(self) -> Vec<Option<&'static str>> {
813 UnlabelledNodes(len) => vec![None; len],
814 AllNodesLabelled(lbls) => lbls.into_iter().map(|l| Some(l)).collect(),
815 SomeNodesLabelled(lbls) => lbls.into_iter().collect(),
819 fn len(&self) -> usize {
821 &UnlabelledNodes(len) => len,
822 &AllNodesLabelled(ref lbls) => lbls.len(),
823 &SomeNodesLabelled(ref lbls) => lbls.len(),
829 fn new(name: &'static str,
830 node_labels: Trivial,
832 node_styles: Option<Vec<Style>>)
834 let count = node_labels.len();
837 node_labels: node_labels.to_opt_strs(),
839 node_styles: match node_styles {
840 Some(nodes) => nodes,
841 None => vec![Style::None; count],
847 impl LabelledGraphWithEscStrs {
848 fn new(name: &'static str,
849 node_labels: Trivial,
851 -> LabelledGraphWithEscStrs {
852 LabelledGraphWithEscStrs { graph: LabelledGraph::new(name, node_labels, edges, None) }
856 fn id_name<'a>(n: &Node) -> Id<'a> {
857 Id::new(format!("N{}", *n)).unwrap()
860 impl<'a> Labeller<'a, Node, &'a Edge> for LabelledGraph {
861 fn graph_id(&'a self) -> Id<'a> {
862 Id::new(&self.name[..]).unwrap()
864 fn node_id(&'a self, n: &Node) -> Id<'a> {
867 fn node_label(&'a self, n: &Node) -> LabelText<'a> {
868 match self.node_labels[*n] {
869 Some(ref l) => LabelStr(l.into_cow()),
870 None => LabelStr(id_name(n).name()),
873 fn edge_label(&'a self, e: &&'a Edge) -> LabelText<'a> {
874 LabelStr(e.label.into_cow())
876 fn node_style(&'a self, n: &Node) -> Style {
879 fn edge_style(&'a self, e: &&'a Edge) -> Style {
884 impl<'a> Labeller<'a, Node, &'a Edge> for LabelledGraphWithEscStrs {
885 fn graph_id(&'a self) -> Id<'a> {
886 self.graph.graph_id()
888 fn node_id(&'a self, n: &Node) -> Id<'a> {
889 self.graph.node_id(n)
891 fn node_label(&'a self, n: &Node) -> LabelText<'a> {
892 match self.graph.node_label(n) {
893 LabelStr(s) | EscStr(s) | HtmlStr(s) => EscStr(s),
896 fn edge_label(&'a self, e: &&'a Edge) -> LabelText<'a> {
897 match self.graph.edge_label(e) {
898 LabelStr(s) | EscStr(s) | HtmlStr(s) => EscStr(s),
903 impl<'a> GraphWalk<'a, Node, &'a Edge> for LabelledGraph {
904 fn nodes(&'a self) -> Nodes<'a, Node> {
905 (0..self.node_labels.len()).collect()
907 fn edges(&'a self) -> Edges<'a, &'a Edge> {
908 self.edges.iter().collect()
910 fn source(&'a self, edge: &&'a Edge) -> Node {
913 fn target(&'a self, edge: &&'a Edge) -> Node {
918 impl<'a> GraphWalk<'a, Node, &'a Edge> for LabelledGraphWithEscStrs {
919 fn nodes(&'a self) -> Nodes<'a, Node> {
922 fn edges(&'a self) -> Edges<'a, &'a Edge> {
925 fn source(&'a self, edge: &&'a Edge) -> Node {
928 fn target(&'a self, edge: &&'a Edge) -> Node {
933 fn test_input(g: LabelledGraph) -> io::Result<String> {
934 let mut writer = Vec::new();
935 render(&g, &mut writer).unwrap();
936 let mut s = String::new();
937 try!(Read::read_to_string(&mut &*writer, &mut s));
941 // All of the tests use raw-strings as the format for the expected outputs,
942 // so that you can cut-and-paste the content into a .dot file yourself to
943 // see what the graphviz visualizer would produce.
947 let labels: Trivial = UnlabelledNodes(0);
948 let r = test_input(LabelledGraph::new("empty_graph", labels, vec![], None));
949 assert_eq!(r.unwrap(),
950 r#"digraph empty_graph {
957 let labels: Trivial = UnlabelledNodes(1);
958 let r = test_input(LabelledGraph::new("single_node", labels, vec![], None));
959 assert_eq!(r.unwrap(),
960 r#"digraph single_node {
967 fn single_node_with_style() {
968 let labels: Trivial = UnlabelledNodes(1);
969 let styles = Some(vec![Style::Dashed]);
970 let r = test_input(LabelledGraph::new("single_node", labels, vec![], styles));
971 assert_eq!(r.unwrap(),
972 r#"digraph single_node {
973 N0[label="N0"][style="dashed"];
980 let labels: Trivial = UnlabelledNodes(2);
981 let result = test_input(LabelledGraph::new("single_edge",
983 vec![edge(0, 1, "E", Style::None)],
985 assert_eq!(result.unwrap(),
986 r#"digraph single_edge {
995 fn single_edge_with_style() {
996 let labels: Trivial = UnlabelledNodes(2);
997 let result = test_input(LabelledGraph::new("single_edge",
999 vec![edge(0, 1, "E", Style::Bold)],
1001 assert_eq!(result.unwrap(),
1002 r#"digraph single_edge {
1005 N0 -> N1[label="E"][style="bold"];
1011 fn test_some_labelled() {
1012 let labels: Trivial = SomeNodesLabelled(vec![Some("A"), None]);
1013 let styles = Some(vec![Style::None, Style::Dotted]);
1014 let result = test_input(LabelledGraph::new("test_some_labelled",
1016 vec![edge(0, 1, "A-1", Style::None)],
1018 assert_eq!(result.unwrap(),
1019 r#"digraph test_some_labelled {
1021 N1[label="N1"][style="dotted"];
1022 N0 -> N1[label="A-1"];
1028 fn single_cyclic_node() {
1029 let labels: Trivial = UnlabelledNodes(1);
1030 let r = test_input(LabelledGraph::new("single_cyclic_node",
1032 vec![edge(0, 0, "E", Style::None)],
1034 assert_eq!(r.unwrap(),
1035 r#"digraph single_cyclic_node {
1037 N0 -> N0[label="E"];
1043 fn hasse_diagram() {
1044 let labels = AllNodesLabelled(vec!["{x,y}", "{x}", "{y}", "{}"]);
1045 let r = test_input(LabelledGraph::new("hasse_diagram",
1047 vec![edge(0, 1, "", Style::None),
1048 edge(0, 2, "", Style::None),
1049 edge(1, 3, "", Style::None),
1050 edge(2, 3, "", Style::None)],
1052 assert_eq!(r.unwrap(),
1053 r#"digraph hasse_diagram {
1067 fn left_aligned_text() {
1068 let labels = AllNodesLabelled(vec![
1080 let mut writer = Vec::new();
1082 let g = LabelledGraphWithEscStrs::new("syntax_tree",
1084 vec![edge(0, 1, "then", Style::None),
1085 edge(0, 2, "else", Style::None),
1086 edge(1, 3, ";", Style::None),
1087 edge(2, 3, ";", Style::None)]);
1089 render(&g, &mut writer).unwrap();
1090 let mut r = String::new();
1091 Read::read_to_string(&mut &*writer, &mut r).unwrap();
1094 r#"digraph syntax_tree {
1095 N0[label="if test {\l branch1\l} else {\l branch2\l}\lafterward\l"];
1096 N1[label="branch1"];
1097 N2[label="branch2"];
1098 N3[label="afterward"];
1099 N0 -> N1[label="then"];
1100 N0 -> N2[label="else"];
1101 N1 -> N3[label=";"];
1102 N2 -> N3[label=";"];
1108 fn simple_id_construction() {
1109 let id1 = Id::new("hello");
1112 Err(..) => panic!("'hello' is not a valid value for id anymore"),
1117 fn badly_formatted_id() {
1118 let id2 = Id::new("Weird { struct : ure } !!!");
1120 Ok(_) => panic!("graphviz id suddenly allows spaces, brackets and stuff"),