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, core, 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, core, into_cow)]
155 //! use std::borrow::IntoCow;
156 //! use std::io::Write;
157 //! use graphviz as dot;
160 //! type Ed<'a> = &'a (usize, usize);
161 //! struct Graph { nodes: Vec<&'static str>, edges: Vec<(usize,usize)> }
163 //! pub fn render_to<W: Write>(output: &mut W) {
164 //! let nodes = vec!("{x,y}","{x}","{y}","{}");
165 //! let edges = vec!((0,1), (0,2), (1,3), (2,3));
166 //! let graph = Graph { nodes: nodes, edges: edges };
168 //! dot::render(&graph, output).unwrap()
171 //! impl<'a> dot::Labeller<'a, Nd, Ed<'a>> for Graph {
172 //! fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example2").unwrap() }
173 //! fn node_id(&'a self, n: &Nd) -> dot::Id<'a> {
174 //! dot::Id::new(format!("N{}", n)).unwrap()
176 //! fn node_label<'b>(&'b self, n: &Nd) -> dot::LabelText<'b> {
177 //! dot::LabelText::LabelStr(self.nodes[*n].as_slice().into_cow())
179 //! fn edge_label<'b>(&'b self, _: &Ed) -> dot::LabelText<'b> {
180 //! dot::LabelText::LabelStr("⊆".into_cow())
184 //! impl<'a> dot::GraphWalk<'a, Nd, Ed<'a>> for Graph {
185 //! fn nodes(&self) -> dot::Nodes<'a,Nd> { (0..self.nodes.len()).collect() }
186 //! fn edges(&'a self) -> dot::Edges<'a,Ed<'a>> { self.edges.iter().collect() }
187 //! fn source(&self, e: &Ed) -> Nd { let & &(s,_) = e; s }
188 //! fn target(&self, e: &Ed) -> Nd { let & &(_,t) = e; t }
191 //! # pub fn main() { render_to(&mut Vec::new()) }
195 //! # pub fn render_to<W:std::io::Write>(output: &mut W) { unimplemented!() }
197 //! use std::fs::File;
198 //! let mut f = File::create("example2.dot").unwrap();
199 //! render_to(&mut f)
203 //! The third example is similar to the second, except now each node and
204 //! edge now carries a reference to the string label for each node as well
205 //! as that node's index. (This is another illustration of how to share
206 //! structure with the graph itself, and why one might want to do so.)
208 //! The output from this example is the same as the second example: the
209 //! Hasse-diagram for the subsets of the set `{x, y}`.
212 //! #![feature(rustc_private, core, into_cow)]
214 //! use std::borrow::IntoCow;
215 //! use std::io::Write;
216 //! use graphviz as dot;
218 //! type Nd<'a> = (usize, &'a str);
219 //! type Ed<'a> = (Nd<'a>, Nd<'a>);
220 //! struct Graph { nodes: Vec<&'static str>, edges: Vec<(usize,usize)> }
222 //! pub fn render_to<W: Write>(output: &mut W) {
223 //! let nodes = vec!("{x,y}","{x}","{y}","{}");
224 //! let edges = vec!((0,1), (0,2), (1,3), (2,3));
225 //! let graph = Graph { nodes: nodes, edges: edges };
227 //! dot::render(&graph, output).unwrap()
230 //! impl<'a> dot::Labeller<'a, Nd<'a>, Ed<'a>> for Graph {
231 //! fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example3").unwrap() }
232 //! fn node_id(&'a self, n: &Nd<'a>) -> dot::Id<'a> {
233 //! dot::Id::new(format!("N{}", n.0)).unwrap()
235 //! fn node_label<'b>(&'b self, n: &Nd<'b>) -> dot::LabelText<'b> {
237 //! dot::LabelText::LabelStr(self.nodes[i].into_cow())
239 //! fn edge_label<'b>(&'b self, _: &Ed<'b>) -> dot::LabelText<'b> {
240 //! dot::LabelText::LabelStr("⊆".into_cow())
244 //! impl<'a> dot::GraphWalk<'a, Nd<'a>, Ed<'a>> for Graph {
245 //! fn nodes(&'a self) -> dot::Nodes<'a,Nd<'a>> {
246 //! self.nodes.iter().map(|s| &s[..]).enumerate().collect()
248 //! fn edges(&'a self) -> dot::Edges<'a,Ed<'a>> {
249 //! self.edges.iter()
250 //! .map(|&(i,j)|((i, &self.nodes[i][..]),
251 //! (j, &self.nodes[j][..])))
254 //! fn source(&self, e: &Ed<'a>) -> Nd<'a> { let &(s,_) = e; s }
255 //! fn target(&self, e: &Ed<'a>) -> Nd<'a> { let &(_,t) = e; t }
258 //! # pub fn main() { render_to(&mut Vec::new()) }
262 //! # pub fn render_to<W:std::io::Write>(output: &mut W) { unimplemented!() }
264 //! use std::fs::File;
265 //! let mut f = File::create("example3.dot").unwrap();
266 //! render_to(&mut f)
272 //! * [Graphviz](http://www.graphviz.org/)
274 //! * [DOT language](http://www.graphviz.org/doc/info/lang.html)
276 // Do not remove on snapshot creation. Needed for bootstrap. (Issue #22364)
277 #![cfg_attr(stage0, feature(custom_attribute))]
278 #![crate_name = "graphviz"]
279 #![unstable(feature = "rustc_private", issue = "27812")]
280 #![feature(staged_api)]
282 #![crate_type = "rlib"]
283 #![crate_type = "dylib"]
284 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
285 html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
286 html_root_url = "https://doc.rust-lang.org/nightly/")]
288 #![feature(into_cow)]
289 #![feature(str_escape)]
291 use self::LabelText::*;
293 use std::borrow::{IntoCow, Cow};
294 use std::io::prelude::*;
297 /// The text for a graphviz label on a node or edge.
298 pub enum LabelText<'a> {
299 /// This kind of label preserves the text directly as is.
301 /// Occurrences of backslashes (`\`) are escaped, and thus appear
302 /// as backslashes in the rendered label.
303 LabelStr(Cow<'a, str>),
305 /// This kind of label uses the graphviz label escString type:
306 /// http://www.graphviz.org/content/attrs#kescString
308 /// Occurrences of backslashes (`\`) are not escaped; instead they
309 /// are interpreted as initiating an escString escape sequence.
311 /// Escape sequences of particular interest: in addition to `\n`
312 /// to break a line (centering the line preceding the `\n`), there
313 /// are also the escape sequences `\l` which left-justifies the
314 /// preceding line and `\r` which right-justifies it.
315 EscStr(Cow<'a, str>),
317 /// This uses a graphviz [HTML string label][html]. The string is
318 /// printed exactly as given, but between `<` and `>`. **No
319 /// escaping is performed.**
321 /// [html]: http://www.graphviz.org/content/node-shapes#html
322 HtmlStr(Cow<'a, str>),
325 /// The style for a node or edge.
326 /// See http://www.graphviz.org/doc/info/attrs.html#k:style for descriptions.
327 /// Note that some of these are not valid for edges.
328 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
343 pub fn as_slice(self) -> &'static str {
346 Style::Solid => "solid",
347 Style::Dashed => "dashed",
348 Style::Dotted => "dotted",
349 Style::Bold => "bold",
350 Style::Rounded => "rounded",
351 Style::Diagonals => "diagonals",
352 Style::Filled => "filled",
353 Style::Striped => "striped",
354 Style::Wedged => "wedged",
359 // There is a tension in the design of the labelling API.
361 // For example, I considered making a `Labeller<T>` trait that
362 // provides labels for `T`, and then making the graph type `G`
363 // implement `Labeller<Node>` and `Labeller<Edge>`. However, this is
364 // not possible without functional dependencies. (One could work
365 // around that, but I did not explore that avenue heavily.)
367 // Another approach that I actually used for a while was to make a
368 // `Label<Context>` trait that is implemented by the client-specific
369 // Node and Edge types (as well as an implementation on Graph itself
370 // for the overall name for the graph). The main disadvantage of this
371 // second approach (compared to having the `G` type parameter
372 // implement a Labelling service) that I have encountered is that it
373 // makes it impossible to use types outside of the current crate
374 // directly as Nodes/Edges; you need to wrap them in newtype'd
375 // structs. See e.g. the `No` and `Ed` structs in the examples. (In
376 // practice clients using a graph in some other crate would need to
377 // provide some sort of adapter shim over the graph anyway to
378 // interface with this library).
380 // Another approach would be to make a single `Labeller<N,E>` trait
381 // that provides three methods (graph_label, node_label, edge_label),
382 // and then make `G` implement `Labeller<N,E>`. At first this did not
383 // appeal to me, since I had thought I would need separate methods on
384 // each data variant for dot-internal identifiers versus user-visible
385 // labels. However, the identifier/label distinction only arises for
386 // nodes; graphs themselves only have identifiers, and edges only have
389 // So in the end I decided to use the third approach described above.
391 /// `Id` is a Graphviz `ID`.
397 /// Creates an `Id` named `name`.
399 /// The caller must ensure that the input conforms to an
400 /// identifier format: it must be a non-empty string made up of
401 /// alphanumeric or underscore characters, not beginning with a
402 /// digit (i.e. the regular expression `[a-zA-Z_][a-zA-Z_0-9]*`).
404 /// (Note: this format is a strict subset of the `ID` format
405 /// defined by the DOT language. This function may change in the
406 /// future to accept a broader subset, or the entirety, of DOT's
409 /// Passing an invalid string (containing spaces, brackets,
410 /// quotes, ...) will return an empty `Err` value.
411 pub fn new<Name: IntoCow<'a, str>>(name: Name) -> Result<Id<'a>, ()> {
412 let name = name.into_cow();
414 let mut chars = name.chars();
416 Some(c) if is_letter_or_underscore(c) => {}
419 if !chars.all(is_constituent) {
423 return Ok(Id{ name: name });
425 fn is_letter_or_underscore(c: char) -> bool {
426 in_range('a', c, 'z') || in_range('A', c, 'Z') || c == '_'
428 fn is_constituent(c: char) -> bool {
429 is_letter_or_underscore(c) || in_range('0', c, '9')
431 fn in_range(low: char, c: char, high: char) -> bool {
432 low as usize <= c as usize && c as usize <= high as usize
436 pub fn as_slice(&'a self) -> &'a str {
440 pub fn name(self) -> Cow<'a, str> {
445 /// Each instance of a type that implements `Label<C>` maps to a
446 /// unique identifier with respect to `C`, which is used to identify
447 /// it in the generated .dot file. They can also provide more
448 /// elaborate (and non-unique) label text that is used in the graphviz
451 /// The graph instance is responsible for providing the DOT compatible
452 /// identifiers for the nodes and (optionally) rendered labels for the nodes and
453 /// edges, as well as an identifier for the graph itself.
454 pub trait Labeller<'a,N,E> {
455 /// Must return a DOT compatible identifier naming the graph.
456 fn graph_id(&'a self) -> Id<'a>;
458 /// Maps `n` to a unique identifier with respect to `self`. The
459 /// implementor is responsible for ensuring that the returned name
460 /// is a valid DOT identifier.
461 fn node_id(&'a self, n: &N) -> Id<'a>;
463 /// Maps `n` to one of the [graphviz `shape` names][1]. If `None`
464 /// is returned, no `shape` attribute is specified.
466 /// [1]: http://www.graphviz.org/content/node-shapes
467 fn node_shape(&'a self, _node: &N) -> Option<LabelText<'a>> {
471 /// Maps `n` to a label that will be used in the rendered output.
472 /// The label need not be unique, and may be the empty string; the
473 /// default is just the output from `node_id`.
474 fn node_label(&'a self, n: &N) -> LabelText<'a> {
475 LabelStr(self.node_id(n).name)
478 /// Maps `e` to a label that will be used in the rendered output.
479 /// The label need not be unique, and may be the empty string; the
480 /// default is in fact the empty string.
481 fn edge_label(&'a self, e: &E) -> LabelText<'a> {
483 LabelStr("".into_cow())
486 /// Maps `n` to a style that will be used in the rendered output.
487 fn node_style(&'a self, _n: &N) -> Style {
491 /// Maps `e` to a style that will be used in the rendered output.
492 fn edge_style(&'a self, _e: &E) -> Style {
497 /// Escape tags in such a way that it is suitable for inclusion in a
498 /// Graphviz HTML label.
499 pub fn escape_html(s: &str) -> String {
501 .replace("&", "&")
502 .replace("\"", """)
503 .replace("<", "<")
504 .replace(">", ">")
507 impl<'a> LabelText<'a> {
508 pub fn label<S: IntoCow<'a, str>>(s: S) -> LabelText<'a> {
509 LabelStr(s.into_cow())
512 pub fn escaped<S: IntoCow<'a, str>>(s: S) -> LabelText<'a> {
516 pub fn html<S: IntoCow<'a, str>>(s: S) -> LabelText<'a> {
517 HtmlStr(s.into_cow())
520 fn escape_char<F>(c: char, mut f: F)
524 // not escaping \\, since Graphviz escString needs to
525 // interpret backslashes; see EscStr above.
527 _ => for c in c.escape_default() {
532 fn escape_str(s: &str) -> String {
533 let mut out = String::with_capacity(s.len());
535 LabelText::escape_char(c, |c| out.push(c));
540 /// Renders text as string suitable for a label in a .dot file.
541 /// This includes quotes or suitable delimeters.
542 pub fn to_dot_string(&self) -> String {
544 &LabelStr(ref s) => format!("\"{}\"", s.escape_default()),
545 &EscStr(ref s) => format!("\"{}\"", LabelText::escape_str(&s[..])),
546 &HtmlStr(ref s) => format!("<{}>", s),
550 /// Decomposes content into string suitable for making EscStr that
551 /// yields same content as self. The result obeys the law
552 /// render(`lt`) == render(`EscStr(lt.pre_escaped_content())`) for
553 /// all `lt: LabelText`.
554 fn pre_escaped_content(self) -> Cow<'a, str> {
557 LabelStr(s) => if s.contains('\\') {
558 (&*s).escape_default().into_cow()
566 /// Puts `prefix` on a line above this label, with a blank line separator.
567 pub fn prefix_line(self, prefix: LabelText) -> LabelText<'static> {
568 prefix.suffix_line(self)
571 /// Puts `suffix` on a line below this label, with a blank line separator.
572 pub fn suffix_line(self, suffix: LabelText) -> LabelText<'static> {
573 let mut prefix = self.pre_escaped_content().into_owned();
574 let suffix = suffix.pre_escaped_content();
575 prefix.push_str(r"\n\n");
576 prefix.push_str(&suffix[..]);
577 EscStr(prefix.into_cow())
581 pub type Nodes<'a,N> = Cow<'a,[N]>;
582 pub type Edges<'a,E> = Cow<'a,[E]>;
584 // (The type parameters in GraphWalk should be associated items,
585 // when/if Rust supports such.)
587 /// GraphWalk is an abstraction over a directed graph = (nodes,edges)
588 /// made up of node handles `N` and edge handles `E`, where each `E`
589 /// can be mapped to its source and target nodes.
591 /// The lifetime parameter `'a` is exposed in this trait (rather than
592 /// introduced as a generic parameter on each method declaration) so
593 /// that a client impl can choose `N` and `E` that have substructure
594 /// that is bound by the self lifetime `'a`.
596 /// The `nodes` and `edges` method each return instantiations of
597 /// `Cow<[T]>` to leave implementors the freedom to create
598 /// entirely new vectors or to pass back slices into internally owned
600 pub trait GraphWalk<'a, N: Clone, E: Clone> {
601 /// Returns all the nodes in this graph.
602 fn nodes(&'a self) -> Nodes<'a, N>;
603 /// Returns all of the edges in this graph.
604 fn edges(&'a self) -> Edges<'a, E>;
605 /// The source node for `edge`.
606 fn source(&'a self, edge: &E) -> N;
607 /// The target node for `edge`.
608 fn target(&'a self, edge: &E) -> N;
611 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
612 pub enum RenderOption {
619 /// Returns vec holding all the default render options.
620 pub fn default_options() -> Vec<RenderOption> {
624 /// Renders directed graph `g` into the writer `w` in DOT syntax.
625 /// (Simple wrapper around `render_opts` that passes a default set of options.)
629 G: Labeller<'a, N, E> + GraphWalk<'a, N, E>,
634 render_opts(g, w, &[])
637 /// Renders directed graph `g` into the writer `w` in DOT syntax.
638 /// (Main entry point for the library.)
639 pub fn render_opts<'a,
642 G: Labeller<'a, N, E> + GraphWalk<'a, N, E>,
646 options: &[RenderOption])
648 fn writeln<W: Write>(w: &mut W, arg: &[&str]) -> io::Result<()> {
650 try!(w.write_all(s.as_bytes()));
655 fn indent<W: Write>(w: &mut W) -> io::Result<()> {
659 try!(writeln(w, &["digraph ", g.graph_id().as_slice(), " {"]));
660 for n in g.nodes().iter() {
662 let id = g.node_id(n);
664 let escaped = &g.node_label(n).to_dot_string();
667 let mut text = vec![id.as_slice()];
669 if !options.contains(&RenderOption::NoNodeLabels) {
670 text.push("[label=");
675 let style = g.node_style(n);
676 if !options.contains(&RenderOption::NoNodeStyles) && style != Style::None {
677 text.push("[style=\"");
678 text.push(style.as_slice());
682 if let Some(s) = g.node_shape(n) {
683 shape = s.to_dot_string();
684 text.push("[shape=");
690 try!(writeln(w, &text));
693 for e in g.edges().iter() {
694 let escaped_label = &g.edge_label(e).to_dot_string();
696 let source = g.source(e);
697 let target = g.target(e);
698 let source_id = g.node_id(&source);
699 let target_id = g.node_id(&target);
701 let mut text = vec![source_id.as_slice(), " -> ", target_id.as_slice()];
703 if !options.contains(&RenderOption::NoEdgeLabels) {
704 text.push("[label=");
705 text.push(escaped_label);
709 let style = g.edge_style(e);
710 if !options.contains(&RenderOption::NoEdgeStyles) && style != Style::None {
711 text.push("[style=\"");
712 text.push(style.as_slice());
717 try!(writeln(w, &text));
725 use self::NodeLabels::*;
726 use super::{Id, Labeller, Nodes, Edges, GraphWalk, render, Style};
727 use super::LabelText::{self, LabelStr, EscStr, HtmlStr};
729 use std::io::prelude::*;
730 use std::borrow::IntoCow;
732 /// each node is an index in a vector in the graph.
741 fn edge(from: usize, to: usize, label: &'static str, style: Style) -> Edge {
742 Edge { from: from, to: to, label: label, style: style }
745 struct LabelledGraph {
746 /// The name for this graph. Used for labelling generated `digraph`.
749 /// Each node is an index into `node_labels`; these labels are
750 /// used as the label text for each node. (The node *names*,
751 /// which are unique identifiers, are derived from their index
754 /// If a node maps to None here, then just use its name as its
756 node_labels: Vec<Option<&'static str>>,
758 node_styles: Vec<Style>,
760 /// Each edge relates a from-index to a to-index along with a
761 /// label; `edges` collects them.
765 // A simple wrapper around LabelledGraph that forces the labels to
766 // be emitted as EscStr.
767 struct LabelledGraphWithEscStrs {
768 graph: LabelledGraph,
772 AllNodesLabelled(Vec<L>),
773 UnlabelledNodes(usize),
774 SomeNodesLabelled(Vec<Option<L>>),
777 type Trivial = NodeLabels<&'static str>;
779 impl NodeLabels<&'static str> {
780 fn to_opt_strs(self) -> Vec<Option<&'static str>> {
782 UnlabelledNodes(len) => vec![None; len],
783 AllNodesLabelled(lbls) => lbls.into_iter().map(|l| Some(l)).collect(),
784 SomeNodesLabelled(lbls) => lbls.into_iter().collect(),
788 fn len(&self) -> usize {
790 &UnlabelledNodes(len) => len,
791 &AllNodesLabelled(ref lbls) => lbls.len(),
792 &SomeNodesLabelled(ref lbls) => lbls.len(),
798 fn new(name: &'static str,
799 node_labels: Trivial,
801 node_styles: Option<Vec<Style>>)
803 let count = node_labels.len();
806 node_labels: node_labels.to_opt_strs(),
808 node_styles: match node_styles {
809 Some(nodes) => nodes,
810 None => vec![Style::None; count],
816 impl LabelledGraphWithEscStrs {
817 fn new(name: &'static str,
818 node_labels: Trivial,
820 -> LabelledGraphWithEscStrs {
821 LabelledGraphWithEscStrs { graph: LabelledGraph::new(name, node_labels, edges, None) }
825 fn id_name<'a>(n: &Node) -> Id<'a> {
826 Id::new(format!("N{}", *n)).unwrap()
829 impl<'a> Labeller<'a, Node, &'a Edge> for LabelledGraph {
830 fn graph_id(&'a self) -> Id<'a> {
831 Id::new(&self.name[..]).unwrap()
833 fn node_id(&'a self, n: &Node) -> Id<'a> {
836 fn node_label(&'a self, n: &Node) -> LabelText<'a> {
837 match self.node_labels[*n] {
838 Some(ref l) => LabelStr(l.into_cow()),
839 None => LabelStr(id_name(n).name()),
842 fn edge_label(&'a self, e: &&'a Edge) -> LabelText<'a> {
843 LabelStr(e.label.into_cow())
845 fn node_style(&'a self, n: &Node) -> Style {
848 fn edge_style(&'a self, e: &&'a Edge) -> Style {
853 impl<'a> Labeller<'a, Node, &'a Edge> for LabelledGraphWithEscStrs {
854 fn graph_id(&'a self) -> Id<'a> {
855 self.graph.graph_id()
857 fn node_id(&'a self, n: &Node) -> Id<'a> {
858 self.graph.node_id(n)
860 fn node_label(&'a self, n: &Node) -> LabelText<'a> {
861 match self.graph.node_label(n) {
862 LabelStr(s) | EscStr(s) | HtmlStr(s) => EscStr(s),
865 fn edge_label(&'a self, e: &&'a Edge) -> LabelText<'a> {
866 match self.graph.edge_label(e) {
867 LabelStr(s) | EscStr(s) | HtmlStr(s) => EscStr(s),
872 impl<'a> GraphWalk<'a, Node, &'a Edge> for LabelledGraph {
873 fn nodes(&'a self) -> Nodes<'a, Node> {
874 (0..self.node_labels.len()).collect()
876 fn edges(&'a self) -> Edges<'a, &'a Edge> {
877 self.edges.iter().collect()
879 fn source(&'a self, edge: &&'a Edge) -> Node {
882 fn target(&'a self, edge: &&'a Edge) -> Node {
887 impl<'a> GraphWalk<'a, Node, &'a Edge> for LabelledGraphWithEscStrs {
888 fn nodes(&'a self) -> Nodes<'a, Node> {
891 fn edges(&'a self) -> Edges<'a, &'a Edge> {
894 fn source(&'a self, edge: &&'a Edge) -> Node {
897 fn target(&'a self, edge: &&'a Edge) -> Node {
902 fn test_input(g: LabelledGraph) -> io::Result<String> {
903 let mut writer = Vec::new();
904 render(&g, &mut writer).unwrap();
905 let mut s = String::new();
906 try!(Read::read_to_string(&mut &*writer, &mut s));
910 // All of the tests use raw-strings as the format for the expected outputs,
911 // so that you can cut-and-paste the content into a .dot file yourself to
912 // see what the graphviz visualizer would produce.
916 let labels: Trivial = UnlabelledNodes(0);
917 let r = test_input(LabelledGraph::new("empty_graph", labels, vec![], None));
918 assert_eq!(r.unwrap(),
919 r#"digraph empty_graph {
926 let labels: Trivial = UnlabelledNodes(1);
927 let r = test_input(LabelledGraph::new("single_node", labels, vec![], None));
928 assert_eq!(r.unwrap(),
929 r#"digraph single_node {
936 fn single_node_with_style() {
937 let labels: Trivial = UnlabelledNodes(1);
938 let styles = Some(vec![Style::Dashed]);
939 let r = test_input(LabelledGraph::new("single_node", labels, vec![], styles));
940 assert_eq!(r.unwrap(),
941 r#"digraph single_node {
942 N0[label="N0"][style="dashed"];
949 let labels: Trivial = UnlabelledNodes(2);
950 let result = test_input(LabelledGraph::new("single_edge",
952 vec![edge(0, 1, "E", Style::None)],
954 assert_eq!(result.unwrap(),
955 r#"digraph single_edge {
964 fn single_edge_with_style() {
965 let labels: Trivial = UnlabelledNodes(2);
966 let result = test_input(LabelledGraph::new("single_edge",
968 vec![edge(0, 1, "E", Style::Bold)],
970 assert_eq!(result.unwrap(),
971 r#"digraph single_edge {
974 N0 -> N1[label="E"][style="bold"];
980 fn test_some_labelled() {
981 let labels: Trivial = SomeNodesLabelled(vec![Some("A"), None]);
982 let styles = Some(vec![Style::None, Style::Dotted]);
983 let result = test_input(LabelledGraph::new("test_some_labelled",
985 vec![edge(0, 1, "A-1", Style::None)],
987 assert_eq!(result.unwrap(),
988 r#"digraph test_some_labelled {
990 N1[label="N1"][style="dotted"];
991 N0 -> N1[label="A-1"];
997 fn single_cyclic_node() {
998 let labels: Trivial = UnlabelledNodes(1);
999 let r = test_input(LabelledGraph::new("single_cyclic_node",
1001 vec![edge(0, 0, "E", Style::None)],
1003 assert_eq!(r.unwrap(),
1004 r#"digraph single_cyclic_node {
1006 N0 -> N0[label="E"];
1012 fn hasse_diagram() {
1013 let labels = AllNodesLabelled(vec!("{x,y}", "{x}", "{y}", "{}"));
1014 let r = test_input(LabelledGraph::new("hasse_diagram",
1016 vec![edge(0, 1, "", Style::None),
1017 edge(0, 2, "", Style::None),
1018 edge(1, 3, "", Style::None),
1019 edge(2, 3, "", Style::None)],
1021 assert_eq!(r.unwrap(),
1022 r#"digraph hasse_diagram {
1036 fn left_aligned_text() {
1037 let labels = AllNodesLabelled(vec!(
1049 let mut writer = Vec::new();
1051 let g = LabelledGraphWithEscStrs::new("syntax_tree",
1053 vec![edge(0, 1, "then", Style::None),
1054 edge(0, 2, "else", Style::None),
1055 edge(1, 3, ";", Style::None),
1056 edge(2, 3, ";", Style::None)]);
1058 render(&g, &mut writer).unwrap();
1059 let mut r = String::new();
1060 Read::read_to_string(&mut &*writer, &mut r).unwrap();
1063 r#"digraph syntax_tree {
1064 N0[label="if test {\l branch1\l} else {\l branch2\l}\lafterward\l"];
1065 N1[label="branch1"];
1066 N2[label="branch2"];
1067 N3[label="afterward"];
1068 N0 -> N1[label="then"];
1069 N0 -> N2[label="else"];
1070 N1 -> N3[label=";"];
1071 N2 -> N3[label=";"];
1077 fn simple_id_construction() {
1078 let id1 = Id::new("hello");
1081 Err(..) => panic!("'hello' is not a valid value for id anymore"),
1086 fn badly_formatted_id() {
1087 let id2 = Id::new("Weird { struct : ure } !!!");
1089 Ok(_) => panic!("graphviz id suddenly allows spaces, brackets and stuff"),