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, into_cow)]
52 //! use std::borrow::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(into_cow)]
285 #![feature(str_escape)]
287 use self::LabelText::*;
289 use std::borrow::{IntoCow, Cow};
290 use std::io::prelude::*;
293 /// The text for a graphviz label on a node or edge.
294 pub enum LabelText<'a> {
295 /// This kind of label preserves the text directly as is.
297 /// Occurrences of backslashes (`\`) are escaped, and thus appear
298 /// as backslashes in the rendered label.
299 LabelStr(Cow<'a, str>),
301 /// This kind of label uses the graphviz label escString type:
302 /// http://www.graphviz.org/content/attrs#kescString
304 /// Occurrences of backslashes (`\`) are not escaped; instead they
305 /// are interpreted as initiating an escString escape sequence.
307 /// Escape sequences of particular interest: in addition to `\n`
308 /// to break a line (centering the line preceding the `\n`), there
309 /// are also the escape sequences `\l` which left-justifies the
310 /// preceding line and `\r` which right-justifies it.
311 EscStr(Cow<'a, str>),
313 /// This uses a graphviz [HTML string label][html]. The string is
314 /// printed exactly as given, but between `<` and `>`. **No
315 /// escaping is performed.**
317 /// [html]: http://www.graphviz.org/content/node-shapes#html
318 HtmlStr(Cow<'a, str>),
321 /// The style for a node or edge.
322 /// See http://www.graphviz.org/doc/info/attrs.html#k:style for descriptions.
323 /// Note that some of these are not valid for edges.
324 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
339 pub fn as_slice(self) -> &'static str {
342 Style::Solid => "solid",
343 Style::Dashed => "dashed",
344 Style::Dotted => "dotted",
345 Style::Bold => "bold",
346 Style::Rounded => "rounded",
347 Style::Diagonals => "diagonals",
348 Style::Filled => "filled",
349 Style::Striped => "striped",
350 Style::Wedged => "wedged",
355 // There is a tension in the design of the labelling API.
357 // For example, I considered making a `Labeller<T>` trait that
358 // provides labels for `T`, and then making the graph type `G`
359 // implement `Labeller<Node>` and `Labeller<Edge>`. However, this is
360 // not possible without functional dependencies. (One could work
361 // around that, but I did not explore that avenue heavily.)
363 // Another approach that I actually used for a while was to make a
364 // `Label<Context>` trait that is implemented by the client-specific
365 // Node and Edge types (as well as an implementation on Graph itself
366 // for the overall name for the graph). The main disadvantage of this
367 // second approach (compared to having the `G` type parameter
368 // implement a Labelling service) that I have encountered is that it
369 // makes it impossible to use types outside of the current crate
370 // directly as Nodes/Edges; you need to wrap them in newtype'd
371 // structs. See e.g. the `No` and `Ed` structs in the examples. (In
372 // practice clients using a graph in some other crate would need to
373 // provide some sort of adapter shim over the graph anyway to
374 // interface with this library).
376 // Another approach would be to make a single `Labeller<N,E>` trait
377 // that provides three methods (graph_label, node_label, edge_label),
378 // and then make `G` implement `Labeller<N,E>`. At first this did not
379 // appeal to me, since I had thought I would need separate methods on
380 // each data variant for dot-internal identifiers versus user-visible
381 // labels. However, the identifier/label distinction only arises for
382 // nodes; graphs themselves only have identifiers, and edges only have
385 // So in the end I decided to use the third approach described above.
387 /// `Id` is a Graphviz `ID`.
393 /// Creates an `Id` named `name`.
395 /// The caller must ensure that the input conforms to an
396 /// identifier format: it must be a non-empty string made up of
397 /// alphanumeric or underscore characters, not beginning with a
398 /// digit (i.e. the regular expression `[a-zA-Z_][a-zA-Z_0-9]*`).
400 /// (Note: this format is a strict subset of the `ID` format
401 /// defined by the DOT language. This function may change in the
402 /// future to accept a broader subset, or the entirety, of DOT's
405 /// Passing an invalid string (containing spaces, brackets,
406 /// quotes, ...) will return an empty `Err` value.
407 pub fn new<Name: IntoCow<'a, str>>(name: Name) -> Result<Id<'a>, ()> {
408 let name = name.into_cow();
410 let mut chars = name.chars();
412 Some(c) if is_letter_or_underscore(c) => {}
415 if !chars.all(is_constituent) {
419 return Ok(Id { name: name });
421 fn is_letter_or_underscore(c: char) -> bool {
422 in_range('a', c, 'z') || in_range('A', c, 'Z') || c == '_'
424 fn is_constituent(c: char) -> bool {
425 is_letter_or_underscore(c) || in_range('0', c, '9')
427 fn in_range(low: char, c: char, high: char) -> bool {
428 low as usize <= c as usize && c as usize <= high as usize
432 pub fn as_slice(&'a self) -> &'a str {
436 pub fn name(self) -> Cow<'a, str> {
441 /// Each instance of a type that implements `Label<C>` maps to a
442 /// unique identifier with respect to `C`, which is used to identify
443 /// it in the generated .dot file. They can also provide more
444 /// elaborate (and non-unique) label text that is used in the graphviz
447 /// The graph instance is responsible for providing the DOT compatible
448 /// identifiers for the nodes and (optionally) rendered labels for the nodes and
449 /// edges, as well as an identifier for the graph itself.
450 pub trait Labeller<'a,N,E> {
451 /// Must return a DOT compatible identifier naming the graph.
452 fn graph_id(&'a self) -> Id<'a>;
454 /// Maps `n` to a unique identifier with respect to `self`. The
455 /// implementor is responsible for ensuring that the returned name
456 /// is a valid DOT identifier.
457 fn node_id(&'a self, n: &N) -> Id<'a>;
459 /// Maps `n` to one of the [graphviz `shape` names][1]. If `None`
460 /// is returned, no `shape` attribute is specified.
462 /// [1]: http://www.graphviz.org/content/node-shapes
463 fn node_shape(&'a self, _node: &N) -> Option<LabelText<'a>> {
467 /// Maps `n` to a label that will be used in the rendered output.
468 /// The label need not be unique, and may be the empty string; the
469 /// default is just the output from `node_id`.
470 fn node_label(&'a self, n: &N) -> LabelText<'a> {
471 LabelStr(self.node_id(n).name)
474 /// Maps `e` to a label that will be used in the rendered output.
475 /// The label need not be unique, and may be the empty string; the
476 /// default is in fact the empty string.
477 fn edge_label(&'a self, e: &E) -> LabelText<'a> {
479 LabelStr("".into_cow())
482 /// Maps `n` to a style that will be used in the rendered output.
483 fn node_style(&'a self, _n: &N) -> Style {
487 /// Maps `e` to a style that will be used in the rendered output.
488 fn edge_style(&'a self, _e: &E) -> Style {
493 /// Escape tags in such a way that it is suitable for inclusion in a
494 /// Graphviz HTML label.
495 pub fn escape_html(s: &str) -> String {
496 s.replace("&", "&")
497 .replace("\"", """)
498 .replace("<", "<")
499 .replace(">", ">")
502 impl<'a> LabelText<'a> {
503 pub fn label<S: IntoCow<'a, str>>(s: S) -> LabelText<'a> {
504 LabelStr(s.into_cow())
507 pub fn escaped<S: IntoCow<'a, str>>(s: S) -> LabelText<'a> {
511 pub fn html<S: IntoCow<'a, str>>(s: S) -> LabelText<'a> {
512 HtmlStr(s.into_cow())
515 fn escape_char<F>(c: char, mut f: F)
519 // not escaping \\, since Graphviz escString needs to
520 // interpret backslashes; see EscStr above.
523 for c in c.escape_default() {
529 fn escape_str(s: &str) -> String {
530 let mut out = String::with_capacity(s.len());
532 LabelText::escape_char(c, |c| out.push(c));
537 /// Renders text as string suitable for a label in a .dot file.
538 /// This includes quotes or suitable delimeters.
539 pub fn to_dot_string(&self) -> String {
541 &LabelStr(ref s) => format!("\"{}\"", s.escape_default()),
542 &EscStr(ref s) => format!("\"{}\"", LabelText::escape_str(&s[..])),
543 &HtmlStr(ref s) => format!("<{}>", s),
547 /// Decomposes content into string suitable for making EscStr that
548 /// yields same content as self. The result obeys the law
549 /// render(`lt`) == render(`EscStr(lt.pre_escaped_content())`) for
550 /// all `lt: LabelText`.
551 fn pre_escaped_content(self) -> Cow<'a, str> {
555 if s.contains('\\') {
556 (&*s).escape_default().into_cow()
565 /// Puts `prefix` on a line above this label, with a blank line separator.
566 pub fn prefix_line(self, prefix: LabelText) -> LabelText<'static> {
567 prefix.suffix_line(self)
570 /// Puts `suffix` on a line below this label, with a blank line separator.
571 pub fn suffix_line(self, suffix: LabelText) -> LabelText<'static> {
572 let mut prefix = self.pre_escaped_content().into_owned();
573 let suffix = suffix.pre_escaped_content();
574 prefix.push_str(r"\n\n");
575 prefix.push_str(&suffix[..]);
576 EscStr(prefix.into_cow())
580 pub type Nodes<'a,N> = Cow<'a,[N]>;
581 pub type Edges<'a,E> = Cow<'a,[E]>;
583 // (The type parameters in GraphWalk should be associated items,
584 // when/if Rust supports such.)
586 /// GraphWalk is an abstraction over a directed graph = (nodes,edges)
587 /// made up of node handles `N` and edge handles `E`, where each `E`
588 /// can be mapped to its source and target nodes.
590 /// The lifetime parameter `'a` is exposed in this trait (rather than
591 /// introduced as a generic parameter on each method declaration) so
592 /// that a client impl can choose `N` and `E` that have substructure
593 /// that is bound by the self lifetime `'a`.
595 /// The `nodes` and `edges` method each return instantiations of
596 /// `Cow<[T]>` to leave implementors the freedom to create
597 /// entirely new vectors or to pass back slices into internally owned
599 pub trait GraphWalk<'a, N: Clone, E: Clone> {
600 /// Returns all the nodes in this graph.
601 fn nodes(&'a self) -> Nodes<'a, N>;
602 /// Returns all of the edges in this graph.
603 fn edges(&'a self) -> Edges<'a, E>;
604 /// The source node for `edge`.
605 fn source(&'a self, edge: &E) -> N;
606 /// The target node for `edge`.
607 fn target(&'a self, edge: &E) -> N;
610 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
611 pub enum RenderOption {
618 /// Returns vec holding all the default render options.
619 pub fn default_options() -> Vec<RenderOption> {
623 /// Renders directed graph `g` into the writer `w` in DOT syntax.
624 /// (Simple wrapper around `render_opts` that passes a default set of options.)
628 G: Labeller<'a, N, E> + GraphWalk<'a, N, E>,
633 render_opts(g, w, &[])
636 /// Renders directed graph `g` into the writer `w` in DOT syntax.
637 /// (Main entry point for the library.)
638 pub fn render_opts<'a,
641 G: Labeller<'a, N, E> + GraphWalk<'a, N, E>,
645 options: &[RenderOption])
647 fn writeln<W: Write>(w: &mut W, arg: &[&str]) -> io::Result<()> {
649 try!(w.write_all(s.as_bytes()));
654 fn indent<W: Write>(w: &mut W) -> io::Result<()> {
658 try!(writeln(w, &["digraph ", g.graph_id().as_slice(), " {"]));
659 for n in g.nodes().iter() {
661 let id = g.node_id(n);
663 let escaped = &g.node_label(n).to_dot_string();
666 let mut text = vec![id.as_slice()];
668 if !options.contains(&RenderOption::NoNodeLabels) {
669 text.push("[label=");
674 let style = g.node_style(n);
675 if !options.contains(&RenderOption::NoNodeStyles) && style != Style::None {
676 text.push("[style=\"");
677 text.push(style.as_slice());
681 if let Some(s) = g.node_shape(n) {
682 shape = s.to_dot_string();
683 text.push("[shape=");
689 try!(writeln(w, &text));
692 for e in g.edges().iter() {
693 let escaped_label = &g.edge_label(e).to_dot_string();
695 let source = g.source(e);
696 let target = g.target(e);
697 let source_id = g.node_id(&source);
698 let target_id = g.node_id(&target);
700 let mut text = vec![source_id.as_slice(), " -> ", target_id.as_slice()];
702 if !options.contains(&RenderOption::NoEdgeLabels) {
703 text.push("[label=");
704 text.push(escaped_label);
708 let style = g.edge_style(e);
709 if !options.contains(&RenderOption::NoEdgeStyles) && style != Style::None {
710 text.push("[style=\"");
711 text.push(style.as_slice());
716 try!(writeln(w, &text));
724 use self::NodeLabels::*;
725 use super::{Id, Labeller, Nodes, Edges, GraphWalk, render, Style};
726 use super::LabelText::{self, LabelStr, EscStr, HtmlStr};
728 use std::io::prelude::*;
729 use std::borrow::IntoCow;
731 /// each node is an index in a vector in the graph.
740 fn edge(from: usize, to: usize, label: &'static str, style: Style) -> Edge {
749 struct LabelledGraph {
750 /// The name for this graph. Used for labelling generated `digraph`.
753 /// Each node is an index into `node_labels`; these labels are
754 /// used as the label text for each node. (The node *names*,
755 /// which are unique identifiers, are derived from their index
758 /// If a node maps to None here, then just use its name as its
760 node_labels: Vec<Option<&'static str>>,
762 node_styles: Vec<Style>,
764 /// Each edge relates a from-index to a to-index along with a
765 /// label; `edges` collects them.
769 // A simple wrapper around LabelledGraph that forces the labels to
770 // be emitted as EscStr.
771 struct LabelledGraphWithEscStrs {
772 graph: LabelledGraph,
776 AllNodesLabelled(Vec<L>),
777 UnlabelledNodes(usize),
778 SomeNodesLabelled(Vec<Option<L>>),
781 type Trivial = NodeLabels<&'static str>;
783 impl NodeLabels<&'static str> {
784 fn to_opt_strs(self) -> Vec<Option<&'static str>> {
786 UnlabelledNodes(len) => vec![None; len],
787 AllNodesLabelled(lbls) => lbls.into_iter().map(|l| Some(l)).collect(),
788 SomeNodesLabelled(lbls) => lbls.into_iter().collect(),
792 fn len(&self) -> usize {
794 &UnlabelledNodes(len) => len,
795 &AllNodesLabelled(ref lbls) => lbls.len(),
796 &SomeNodesLabelled(ref lbls) => lbls.len(),
802 fn new(name: &'static str,
803 node_labels: Trivial,
805 node_styles: Option<Vec<Style>>)
807 let count = node_labels.len();
810 node_labels: node_labels.to_opt_strs(),
812 node_styles: match node_styles {
813 Some(nodes) => nodes,
814 None => vec![Style::None; count],
820 impl LabelledGraphWithEscStrs {
821 fn new(name: &'static str,
822 node_labels: Trivial,
824 -> LabelledGraphWithEscStrs {
825 LabelledGraphWithEscStrs { graph: LabelledGraph::new(name, node_labels, edges, None) }
829 fn id_name<'a>(n: &Node) -> Id<'a> {
830 Id::new(format!("N{}", *n)).unwrap()
833 impl<'a> Labeller<'a, Node, &'a Edge> for LabelledGraph {
834 fn graph_id(&'a self) -> Id<'a> {
835 Id::new(&self.name[..]).unwrap()
837 fn node_id(&'a self, n: &Node) -> Id<'a> {
840 fn node_label(&'a self, n: &Node) -> LabelText<'a> {
841 match self.node_labels[*n] {
842 Some(ref l) => LabelStr(l.into_cow()),
843 None => LabelStr(id_name(n).name()),
846 fn edge_label(&'a self, e: &&'a Edge) -> LabelText<'a> {
847 LabelStr(e.label.into_cow())
849 fn node_style(&'a self, n: &Node) -> Style {
852 fn edge_style(&'a self, e: &&'a Edge) -> Style {
857 impl<'a> Labeller<'a, Node, &'a Edge> for LabelledGraphWithEscStrs {
858 fn graph_id(&'a self) -> Id<'a> {
859 self.graph.graph_id()
861 fn node_id(&'a self, n: &Node) -> Id<'a> {
862 self.graph.node_id(n)
864 fn node_label(&'a self, n: &Node) -> LabelText<'a> {
865 match self.graph.node_label(n) {
866 LabelStr(s) | EscStr(s) | HtmlStr(s) => EscStr(s),
869 fn edge_label(&'a self, e: &&'a Edge) -> LabelText<'a> {
870 match self.graph.edge_label(e) {
871 LabelStr(s) | EscStr(s) | HtmlStr(s) => EscStr(s),
876 impl<'a> GraphWalk<'a, Node, &'a Edge> for LabelledGraph {
877 fn nodes(&'a self) -> Nodes<'a, Node> {
878 (0..self.node_labels.len()).collect()
880 fn edges(&'a self) -> Edges<'a, &'a Edge> {
881 self.edges.iter().collect()
883 fn source(&'a self, edge: &&'a Edge) -> Node {
886 fn target(&'a self, edge: &&'a Edge) -> Node {
891 impl<'a> GraphWalk<'a, Node, &'a Edge> for LabelledGraphWithEscStrs {
892 fn nodes(&'a self) -> Nodes<'a, Node> {
895 fn edges(&'a self) -> Edges<'a, &'a Edge> {
898 fn source(&'a self, edge: &&'a Edge) -> Node {
901 fn target(&'a self, edge: &&'a Edge) -> Node {
906 fn test_input(g: LabelledGraph) -> io::Result<String> {
907 let mut writer = Vec::new();
908 render(&g, &mut writer).unwrap();
909 let mut s = String::new();
910 try!(Read::read_to_string(&mut &*writer, &mut s));
914 // All of the tests use raw-strings as the format for the expected outputs,
915 // so that you can cut-and-paste the content into a .dot file yourself to
916 // see what the graphviz visualizer would produce.
920 let labels: Trivial = UnlabelledNodes(0);
921 let r = test_input(LabelledGraph::new("empty_graph", labels, vec![], None));
922 assert_eq!(r.unwrap(),
923 r#"digraph empty_graph {
930 let labels: Trivial = UnlabelledNodes(1);
931 let r = test_input(LabelledGraph::new("single_node", labels, vec![], None));
932 assert_eq!(r.unwrap(),
933 r#"digraph single_node {
940 fn single_node_with_style() {
941 let labels: Trivial = UnlabelledNodes(1);
942 let styles = Some(vec![Style::Dashed]);
943 let r = test_input(LabelledGraph::new("single_node", labels, vec![], styles));
944 assert_eq!(r.unwrap(),
945 r#"digraph single_node {
946 N0[label="N0"][style="dashed"];
953 let labels: Trivial = UnlabelledNodes(2);
954 let result = test_input(LabelledGraph::new("single_edge",
956 vec![edge(0, 1, "E", Style::None)],
958 assert_eq!(result.unwrap(),
959 r#"digraph single_edge {
968 fn single_edge_with_style() {
969 let labels: Trivial = UnlabelledNodes(2);
970 let result = test_input(LabelledGraph::new("single_edge",
972 vec![edge(0, 1, "E", Style::Bold)],
974 assert_eq!(result.unwrap(),
975 r#"digraph single_edge {
978 N0 -> N1[label="E"][style="bold"];
984 fn test_some_labelled() {
985 let labels: Trivial = SomeNodesLabelled(vec![Some("A"), None]);
986 let styles = Some(vec![Style::None, Style::Dotted]);
987 let result = test_input(LabelledGraph::new("test_some_labelled",
989 vec![edge(0, 1, "A-1", Style::None)],
991 assert_eq!(result.unwrap(),
992 r#"digraph test_some_labelled {
994 N1[label="N1"][style="dotted"];
995 N0 -> N1[label="A-1"];
1001 fn single_cyclic_node() {
1002 let labels: Trivial = UnlabelledNodes(1);
1003 let r = test_input(LabelledGraph::new("single_cyclic_node",
1005 vec![edge(0, 0, "E", Style::None)],
1007 assert_eq!(r.unwrap(),
1008 r#"digraph single_cyclic_node {
1010 N0 -> N0[label="E"];
1016 fn hasse_diagram() {
1017 let labels = AllNodesLabelled(vec!["{x,y}", "{x}", "{y}", "{}"]);
1018 let r = test_input(LabelledGraph::new("hasse_diagram",
1020 vec![edge(0, 1, "", Style::None),
1021 edge(0, 2, "", Style::None),
1022 edge(1, 3, "", Style::None),
1023 edge(2, 3, "", Style::None)],
1025 assert_eq!(r.unwrap(),
1026 r#"digraph hasse_diagram {
1040 fn left_aligned_text() {
1041 let labels = AllNodesLabelled(vec![
1053 let mut writer = Vec::new();
1055 let g = LabelledGraphWithEscStrs::new("syntax_tree",
1057 vec![edge(0, 1, "then", Style::None),
1058 edge(0, 2, "else", Style::None),
1059 edge(1, 3, ";", Style::None),
1060 edge(2, 3, ";", Style::None)]);
1062 render(&g, &mut writer).unwrap();
1063 let mut r = String::new();
1064 Read::read_to_string(&mut &*writer, &mut r).unwrap();
1067 r#"digraph syntax_tree {
1068 N0[label="if test {\l branch1\l} else {\l branch2\l}\lafterward\l"];
1069 N1[label="branch1"];
1070 N2[label="branch2"];
1071 N3[label="afterward"];
1072 N0 -> N1[label="then"];
1073 N0 -> N2[label="else"];
1074 N1 -> N3[label=";"];
1075 N2 -> N3[label=";"];
1081 fn simple_id_construction() {
1082 let id1 = Id::new("hello");
1085 Err(..) => panic!("'hello' is not a valid value for id anymore"),
1090 fn badly_formatted_id() {
1091 let id2 = Id::new("Weird { struct : ure } !!!");
1093 Ok(_) => panic!("graphviz id suddenly allows spaces, brackets and stuff"),