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)]
299 use self::LabelText::*;
301 use std::borrow::{Cow, ToOwned};
302 use std::io::prelude::*;
305 /// The text for a graphviz label on a node or edge.
306 pub enum LabelText<'a> {
307 /// This kind of label preserves the text directly as is.
309 /// Occurrences of backslashes (`\`) are escaped, and thus appear
310 /// as backslashes in the rendered label.
311 LabelStr(Cow<'a, str>),
313 /// This kind of label uses the graphviz label escString type:
314 /// http://www.graphviz.org/content/attrs#kescString
316 /// Occurrences of backslashes (`\`) are not escaped; instead they
317 /// are interpreted as initiating an escString escape sequence.
319 /// Escape sequences of particular interest: in addition to `\n`
320 /// to break a line (centering the line preceding the `\n`), there
321 /// are also the escape sequences `\l` which left-justifies the
322 /// preceding line and `\r` which right-justifies it.
323 EscStr(Cow<'a, str>),
325 /// This uses a graphviz [HTML string label][html]. The string is
326 /// printed exactly as given, but between `<` and `>`. **No
327 /// escaping is performed.**
329 /// [html]: http://www.graphviz.org/content/node-shapes#html
330 HtmlStr(Cow<'a, str>),
333 /// The style for a node or edge.
334 /// See http://www.graphviz.org/doc/info/attrs.html#k:style for descriptions.
335 /// Note that some of these are not valid for edges.
336 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
351 pub fn as_slice(self) -> &'static str {
354 Style::Solid => "solid",
355 Style::Dashed => "dashed",
356 Style::Dotted => "dotted",
357 Style::Bold => "bold",
358 Style::Rounded => "rounded",
359 Style::Diagonals => "diagonals",
360 Style::Filled => "filled",
361 Style::Striped => "striped",
362 Style::Wedged => "wedged",
367 // There is a tension in the design of the labelling API.
369 // For example, I considered making a `Labeller<T>` trait that
370 // provides labels for `T`, and then making the graph type `G`
371 // implement `Labeller<Node>` and `Labeller<Edge>`. However, this is
372 // not possible without functional dependencies. (One could work
373 // around that, but I did not explore that avenue heavily.)
375 // Another approach that I actually used for a while was to make a
376 // `Label<Context>` trait that is implemented by the client-specific
377 // Node and Edge types (as well as an implementation on Graph itself
378 // for the overall name for the graph). The main disadvantage of this
379 // second approach (compared to having the `G` type parameter
380 // implement a Labelling service) that I have encountered is that it
381 // makes it impossible to use types outside of the current crate
382 // directly as Nodes/Edges; you need to wrap them in newtype'd
383 // structs. See e.g. the `No` and `Ed` structs in the examples. (In
384 // practice clients using a graph in some other crate would need to
385 // provide some sort of adapter shim over the graph anyway to
386 // interface with this library).
388 // Another approach would be to make a single `Labeller<N,E>` trait
389 // that provides three methods (graph_label, node_label, edge_label),
390 // and then make `G` implement `Labeller<N,E>`. At first this did not
391 // appeal to me, since I had thought I would need separate methods on
392 // each data variant for dot-internal identifiers versus user-visible
393 // labels. However, the identifier/label distinction only arises for
394 // nodes; graphs themselves only have identifiers, and edges only have
397 // So in the end I decided to use the third approach described above.
399 /// `Id` is a Graphviz `ID`.
405 /// Creates an `Id` named `name`.
407 /// The caller must ensure that the input conforms to an
408 /// identifier format: it must be a non-empty string made up of
409 /// alphanumeric or underscore characters, not beginning with a
410 /// digit (i.e. the regular expression `[a-zA-Z_][a-zA-Z_0-9]*`).
412 /// (Note: this format is a strict subset of the `ID` format
413 /// defined by the DOT language. This function may change in the
414 /// future to accept a broader subset, or the entirety, of DOT's
417 /// Passing an invalid string (containing spaces, brackets,
418 /// quotes, ...) will return an empty `Err` value.
419 pub fn new<Name: IntoCow<'a, str>>(name: Name) -> Result<Id<'a>, ()> {
420 let name = name.into_cow();
422 let mut chars = name.chars();
424 Some(c) if is_letter_or_underscore(c) => {}
427 if !chars.all(is_constituent) {
431 return Ok(Id { name: name });
433 fn is_letter_or_underscore(c: char) -> bool {
434 in_range('a', c, 'z') || in_range('A', c, 'Z') || c == '_'
436 fn is_constituent(c: char) -> bool {
437 is_letter_or_underscore(c) || in_range('0', c, '9')
439 fn in_range(low: char, c: char, high: char) -> bool {
440 low as usize <= c as usize && c as usize <= high as usize
444 pub fn as_slice(&'a self) -> &'a str {
448 pub fn name(self) -> Cow<'a, str> {
453 /// Each instance of a type that implements `Label<C>` maps to a
454 /// unique identifier with respect to `C`, which is used to identify
455 /// it in the generated .dot file. They can also provide more
456 /// elaborate (and non-unique) label text that is used in the graphviz
459 /// The graph instance is responsible for providing the DOT compatible
460 /// identifiers for the nodes and (optionally) rendered labels for the nodes and
461 /// edges, as well as an identifier for the graph itself.
462 pub trait Labeller<'a> {
466 /// Must return a DOT compatible identifier naming the graph.
467 fn graph_id(&'a self) -> Id<'a>;
469 /// Maps `n` to a unique identifier with respect to `self`. The
470 /// implementor is responsible for ensuring that the returned name
471 /// is a valid DOT identifier.
472 fn node_id(&'a self, n: &Self::Node) -> Id<'a>;
474 /// Maps `n` to one of the [graphviz `shape` names][1]. If `None`
475 /// is returned, no `shape` attribute is specified.
477 /// [1]: http://www.graphviz.org/content/node-shapes
478 fn node_shape(&'a self, _node: &Self::Node) -> Option<LabelText<'a>> {
482 /// Maps `n` to a label that will be used in the rendered output.
483 /// The label need not be unique, and may be the empty string; the
484 /// default is just the output from `node_id`.
485 fn node_label(&'a self, n: &Self::Node) -> LabelText<'a> {
486 LabelStr(self.node_id(n).name)
489 /// Maps `e` to a label that will be used in the rendered output.
490 /// The label need not be unique, and may be the empty string; the
491 /// default is in fact the empty string.
492 fn edge_label(&'a self, e: &Self::Edge) -> LabelText<'a> {
494 LabelStr("".into_cow())
497 /// Maps `n` to a style that will be used in the rendered output.
498 fn node_style(&'a self, _n: &Self::Node) -> Style {
502 /// Maps `e` to a style that will be used in the rendered output.
503 fn edge_style(&'a self, _e: &Self::Edge) -> Style {
508 /// Escape tags in such a way that it is suitable for inclusion in a
509 /// Graphviz HTML label.
510 pub fn escape_html(s: &str) -> String {
511 s.replace("&", "&")
512 .replace("\"", """)
513 .replace("<", "<")
514 .replace(">", ">")
517 impl<'a> LabelText<'a> {
518 pub fn label<S: IntoCow<'a, str>>(s: S) -> LabelText<'a> {
519 LabelStr(s.into_cow())
522 pub fn escaped<S: IntoCow<'a, str>>(s: S) -> LabelText<'a> {
526 pub fn html<S: IntoCow<'a, str>>(s: S) -> LabelText<'a> {
527 HtmlStr(s.into_cow())
530 fn escape_char<F>(c: char, mut f: F)
534 // not escaping \\, since Graphviz escString needs to
535 // interpret backslashes; see EscStr above.
538 for c in c.escape_default() {
544 fn escape_str(s: &str) -> String {
545 let mut out = String::with_capacity(s.len());
547 LabelText::escape_char(c, |c| out.push(c));
552 /// Renders text as string suitable for a label in a .dot file.
553 /// This includes quotes or suitable delimeters.
554 pub fn to_dot_string(&self) -> String {
556 &LabelStr(ref s) => format!("\"{}\"", s.escape_default()),
557 &EscStr(ref s) => format!("\"{}\"", LabelText::escape_str(&s[..])),
558 &HtmlStr(ref s) => format!("<{}>", s),
562 /// Decomposes content into string suitable for making EscStr that
563 /// yields same content as self. The result obeys the law
564 /// render(`lt`) == render(`EscStr(lt.pre_escaped_content())`) for
565 /// all `lt: LabelText`.
566 fn pre_escaped_content(self) -> Cow<'a, str> {
570 if s.contains('\\') {
571 (&*s).escape_default().into_cow()
580 /// Puts `prefix` on a line above this label, with a blank line separator.
581 pub fn prefix_line(self, prefix: LabelText) -> LabelText<'static> {
582 prefix.suffix_line(self)
585 /// Puts `suffix` on a line below this label, with a blank line separator.
586 pub fn suffix_line(self, suffix: LabelText) -> LabelText<'static> {
587 let mut prefix = self.pre_escaped_content().into_owned();
588 let suffix = suffix.pre_escaped_content();
589 prefix.push_str(r"\n\n");
590 prefix.push_str(&suffix[..]);
591 EscStr(prefix.into_cow())
595 pub type Nodes<'a,N> = Cow<'a,[N]>;
596 pub type Edges<'a,E> = Cow<'a,[E]>;
598 // (The type parameters in GraphWalk should be associated items,
599 // when/if Rust supports such.)
601 /// GraphWalk is an abstraction over a directed graph = (nodes,edges)
602 /// made up of node handles `N` and edge handles `E`, where each `E`
603 /// can be mapped to its source and target nodes.
605 /// The lifetime parameter `'a` is exposed in this trait (rather than
606 /// introduced as a generic parameter on each method declaration) so
607 /// that a client impl can choose `N` and `E` that have substructure
608 /// that is bound by the self lifetime `'a`.
610 /// The `nodes` and `edges` method each return instantiations of
611 /// `Cow<[T]>` to leave implementors the freedom to create
612 /// entirely new vectors or to pass back slices into internally owned
614 pub trait GraphWalk<'a> {
618 /// Returns all the nodes in this graph.
619 fn nodes(&'a self) -> Nodes<'a, Self::Node>;
620 /// Returns all of the edges in this graph.
621 fn edges(&'a self) -> Edges<'a, Self::Edge>;
622 /// The source node for `edge`.
623 fn source(&'a self, edge: &Self::Edge) -> Self::Node;
624 /// The target node for `edge`.
625 fn target(&'a self, edge: &Self::Edge) -> Self::Node;
628 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
629 pub enum RenderOption {
636 /// Returns vec holding all the default render options.
637 pub fn default_options() -> Vec<RenderOption> {
641 /// Renders directed graph `g` into the writer `w` in DOT syntax.
642 /// (Simple wrapper around `render_opts` that passes a default set of options.)
643 pub fn render<'a,N,E,G,W>(g: &'a G, w: &mut W) -> io::Result<()>
646 G: Labeller<'a, Node=N, Edge=E> + GraphWalk<'a, Node=N, Edge=E>,
649 render_opts(g, w, &[])
652 /// Renders directed graph `g` into the writer `w` in DOT syntax.
653 /// (Main entry point for the library.)
654 pub fn render_opts<'a, N, E, G, W>(g: &'a G,
656 options: &[RenderOption])
660 G: Labeller<'a, Node=N, Edge=E> + GraphWalk<'a, Node=N, Edge=E>,
663 fn writeln<W: Write>(w: &mut W, arg: &[&str]) -> io::Result<()> {
665 w.write_all(s.as_bytes())?;
670 fn indent<W: Write>(w: &mut W) -> io::Result<()> {
674 writeln(w, &["digraph ", g.graph_id().as_slice(), " {"])?;
675 for n in g.nodes().iter() {
677 let id = g.node_id(n);
679 let escaped = &g.node_label(n).to_dot_string();
682 let mut text = vec![id.as_slice()];
684 if !options.contains(&RenderOption::NoNodeLabels) {
685 text.push("[label=");
690 let style = g.node_style(n);
691 if !options.contains(&RenderOption::NoNodeStyles) && style != Style::None {
692 text.push("[style=\"");
693 text.push(style.as_slice());
697 if let Some(s) = g.node_shape(n) {
698 shape = s.to_dot_string();
699 text.push("[shape=");
708 for e in g.edges().iter() {
709 let escaped_label = &g.edge_label(e).to_dot_string();
711 let source = g.source(e);
712 let target = g.target(e);
713 let source_id = g.node_id(&source);
714 let target_id = g.node_id(&target);
716 let mut text = vec![source_id.as_slice(), " -> ", target_id.as_slice()];
718 if !options.contains(&RenderOption::NoEdgeLabels) {
719 text.push("[label=");
720 text.push(escaped_label);
724 let style = g.edge_style(e);
725 if !options.contains(&RenderOption::NoEdgeStyles) && style != Style::None {
726 text.push("[style=\"");
727 text.push(style.as_slice());
738 pub trait IntoCow<'a, B: ?Sized> where B: ToOwned {
739 fn into_cow(self) -> Cow<'a, B>;
742 impl<'a> IntoCow<'a, str> for String {
743 fn into_cow(self) -> Cow<'a, str> {
748 impl<'a> IntoCow<'a, str> for &'a str {
749 fn into_cow(self) -> Cow<'a, str> {
754 impl<'a, T: Clone> IntoCow<'a, [T]> for Vec<T> {
755 fn into_cow(self) -> Cow<'a, [T]> {
760 impl<'a, T: Clone> IntoCow<'a, [T]> for &'a [T] {
761 fn into_cow(self) -> Cow<'a, [T]> {
768 use self::NodeLabels::*;
769 use super::{Id, Labeller, Nodes, Edges, GraphWalk, render, Style};
770 use super::LabelText::{self, LabelStr, EscStr, HtmlStr};
772 use std::io::prelude::*;
775 /// each node is an index in a vector in the graph.
784 fn edge(from: usize, to: usize, label: &'static str, style: Style) -> Edge {
793 struct LabelledGraph {
794 /// The name for this graph. Used for labelling generated `digraph`.
797 /// Each node is an index into `node_labels`; these labels are
798 /// used as the label text for each node. (The node *names*,
799 /// which are unique identifiers, are derived from their index
802 /// If a node maps to None here, then just use its name as its
804 node_labels: Vec<Option<&'static str>>,
806 node_styles: Vec<Style>,
808 /// Each edge relates a from-index to a to-index along with a
809 /// label; `edges` collects them.
813 // A simple wrapper around LabelledGraph that forces the labels to
814 // be emitted as EscStr.
815 struct LabelledGraphWithEscStrs {
816 graph: LabelledGraph,
820 AllNodesLabelled(Vec<L>),
821 UnlabelledNodes(usize),
822 SomeNodesLabelled(Vec<Option<L>>),
825 type Trivial = NodeLabels<&'static str>;
827 impl NodeLabels<&'static str> {
828 fn to_opt_strs(self) -> Vec<Option<&'static str>> {
830 UnlabelledNodes(len) => vec![None; len],
831 AllNodesLabelled(lbls) => lbls.into_iter().map(|l| Some(l)).collect(),
832 SomeNodesLabelled(lbls) => lbls.into_iter().collect(),
836 fn len(&self) -> usize {
838 &UnlabelledNodes(len) => len,
839 &AllNodesLabelled(ref lbls) => lbls.len(),
840 &SomeNodesLabelled(ref lbls) => lbls.len(),
846 fn new(name: &'static str,
847 node_labels: Trivial,
849 node_styles: Option<Vec<Style>>)
851 let count = node_labels.len();
854 node_labels: node_labels.to_opt_strs(),
856 node_styles: match node_styles {
857 Some(nodes) => nodes,
858 None => vec![Style::None; count],
864 impl LabelledGraphWithEscStrs {
865 fn new(name: &'static str,
866 node_labels: Trivial,
868 -> LabelledGraphWithEscStrs {
869 LabelledGraphWithEscStrs { graph: LabelledGraph::new(name, node_labels, edges, None) }
873 fn id_name<'a>(n: &Node) -> Id<'a> {
874 Id::new(format!("N{}", *n)).unwrap()
877 impl<'a> Labeller<'a> for LabelledGraph {
879 type Edge = &'a Edge;
880 fn graph_id(&'a self) -> Id<'a> {
881 Id::new(&self.name[..]).unwrap()
883 fn node_id(&'a self, n: &Node) -> Id<'a> {
886 fn node_label(&'a self, n: &Node) -> LabelText<'a> {
887 match self.node_labels[*n] {
888 Some(ref l) => LabelStr(l.into_cow()),
889 None => LabelStr(id_name(n).name()),
892 fn edge_label(&'a self, e: &&'a Edge) -> LabelText<'a> {
893 LabelStr(e.label.into_cow())
895 fn node_style(&'a self, n: &Node) -> Style {
898 fn edge_style(&'a self, e: &&'a Edge) -> Style {
903 impl<'a> Labeller<'a> for LabelledGraphWithEscStrs {
905 type Edge = &'a Edge;
906 fn graph_id(&'a self) -> Id<'a> {
907 self.graph.graph_id()
909 fn node_id(&'a self, n: &Node) -> Id<'a> {
910 self.graph.node_id(n)
912 fn node_label(&'a self, n: &Node) -> LabelText<'a> {
913 match self.graph.node_label(n) {
914 LabelStr(s) | EscStr(s) | HtmlStr(s) => EscStr(s),
917 fn edge_label(&'a self, e: &&'a Edge) -> LabelText<'a> {
918 match self.graph.edge_label(e) {
919 LabelStr(s) | EscStr(s) | HtmlStr(s) => EscStr(s),
924 impl<'a> GraphWalk<'a> for LabelledGraph {
926 type Edge = &'a Edge;
927 fn nodes(&'a self) -> Nodes<'a, Node> {
928 (0..self.node_labels.len()).collect()
930 fn edges(&'a self) -> Edges<'a, &'a Edge> {
931 self.edges.iter().collect()
933 fn source(&'a self, edge: &&'a Edge) -> Node {
936 fn target(&'a self, edge: &&'a Edge) -> Node {
941 impl<'a> GraphWalk<'a> for LabelledGraphWithEscStrs {
943 type Edge = &'a Edge;
944 fn nodes(&'a self) -> Nodes<'a, Node> {
947 fn edges(&'a self) -> Edges<'a, &'a Edge> {
950 fn source(&'a self, edge: &&'a Edge) -> Node {
953 fn target(&'a self, edge: &&'a Edge) -> Node {
958 fn test_input(g: LabelledGraph) -> io::Result<String> {
959 let mut writer = Vec::new();
960 render(&g, &mut writer).unwrap();
961 let mut s = String::new();
962 Read::read_to_string(&mut &*writer, &mut s)?;
966 // All of the tests use raw-strings as the format for the expected outputs,
967 // so that you can cut-and-paste the content into a .dot file yourself to
968 // see what the graphviz visualizer would produce.
972 let labels: Trivial = UnlabelledNodes(0);
973 let r = test_input(LabelledGraph::new("empty_graph", labels, vec![], None));
974 assert_eq!(r.unwrap(),
975 r#"digraph empty_graph {
982 let labels: Trivial = UnlabelledNodes(1);
983 let r = test_input(LabelledGraph::new("single_node", labels, vec![], None));
984 assert_eq!(r.unwrap(),
985 r#"digraph single_node {
992 fn single_node_with_style() {
993 let labels: Trivial = UnlabelledNodes(1);
994 let styles = Some(vec![Style::Dashed]);
995 let r = test_input(LabelledGraph::new("single_node", labels, vec![], styles));
996 assert_eq!(r.unwrap(),
997 r#"digraph single_node {
998 N0[label="N0"][style="dashed"];
1005 let labels: Trivial = UnlabelledNodes(2);
1006 let result = test_input(LabelledGraph::new("single_edge",
1008 vec![edge(0, 1, "E", Style::None)],
1010 assert_eq!(result.unwrap(),
1011 r#"digraph single_edge {
1014 N0 -> N1[label="E"];
1020 fn single_edge_with_style() {
1021 let labels: Trivial = UnlabelledNodes(2);
1022 let result = test_input(LabelledGraph::new("single_edge",
1024 vec![edge(0, 1, "E", Style::Bold)],
1026 assert_eq!(result.unwrap(),
1027 r#"digraph single_edge {
1030 N0 -> N1[label="E"][style="bold"];
1036 fn test_some_labelled() {
1037 let labels: Trivial = SomeNodesLabelled(vec![Some("A"), None]);
1038 let styles = Some(vec![Style::None, Style::Dotted]);
1039 let result = test_input(LabelledGraph::new("test_some_labelled",
1041 vec![edge(0, 1, "A-1", Style::None)],
1043 assert_eq!(result.unwrap(),
1044 r#"digraph test_some_labelled {
1046 N1[label="N1"][style="dotted"];
1047 N0 -> N1[label="A-1"];
1053 fn single_cyclic_node() {
1054 let labels: Trivial = UnlabelledNodes(1);
1055 let r = test_input(LabelledGraph::new("single_cyclic_node",
1057 vec![edge(0, 0, "E", Style::None)],
1059 assert_eq!(r.unwrap(),
1060 r#"digraph single_cyclic_node {
1062 N0 -> N0[label="E"];
1068 fn hasse_diagram() {
1069 let labels = AllNodesLabelled(vec!["{x,y}", "{x}", "{y}", "{}"]);
1070 let r = test_input(LabelledGraph::new("hasse_diagram",
1072 vec![edge(0, 1, "", Style::None),
1073 edge(0, 2, "", Style::None),
1074 edge(1, 3, "", Style::None),
1075 edge(2, 3, "", Style::None)],
1077 assert_eq!(r.unwrap(),
1078 r#"digraph hasse_diagram {
1092 fn left_aligned_text() {
1093 let labels = AllNodesLabelled(vec![
1105 let mut writer = Vec::new();
1107 let g = LabelledGraphWithEscStrs::new("syntax_tree",
1109 vec![edge(0, 1, "then", Style::None),
1110 edge(0, 2, "else", Style::None),
1111 edge(1, 3, ";", Style::None),
1112 edge(2, 3, ";", Style::None)]);
1114 render(&g, &mut writer).unwrap();
1115 let mut r = String::new();
1116 Read::read_to_string(&mut &*writer, &mut r).unwrap();
1119 r#"digraph syntax_tree {
1120 N0[label="if test {\l branch1\l} else {\l branch2\l}\lafterward\l"];
1121 N1[label="branch1"];
1122 N2[label="branch2"];
1123 N3[label="afterward"];
1124 N0 -> N1[label="then"];
1125 N0 -> N2[label="else"];
1126 N1 -> N3[label=";"];
1127 N2 -> N3[label=";"];
1133 fn simple_id_construction() {
1134 let id1 = Id::new("hello");
1137 Err(..) => panic!("'hello' is not a valid value for id anymore"),
1142 fn badly_formatted_id() {
1143 let id2 = Id::new("Weird { struct : ure } !!!");
1145 Ok(_) => panic!("graphviz id suddenly allows spaces, brackets and stuff"),