rust/src/libgraphviz/lib.rs
Eli Friedman bbbfed2f93 Use https URLs to refer to rust-lang.org where appropriate.
Also fixes a few outdated links.
2015-08-09 14:28:46 -07:00

1028 lines
34 KiB
Rust

// Copyright 2014-2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Generate files suitable for use with [Graphviz](http://www.graphviz.org/)
//!
//! The `render` function generates output (e.g. an `output.dot` file) for
//! use with [Graphviz](http://www.graphviz.org/) by walking a labelled
//! graph. (Graphviz can then automatically lay out the nodes and edges
//! of the graph, and also optionally render the graph as an image or
//! other [output formats](
//! http://www.graphviz.org/content/output-formats), such as SVG.)
//!
//! Rather than impose some particular graph data structure on clients,
//! this library exposes two traits that clients can implement on their
//! own structs before handing them over to the rendering function.
//!
//! Note: This library does not yet provide access to the full
//! expressiveness of the [DOT language](
//! http://www.graphviz.org/doc/info/lang.html). For example, there are
//! many [attributes](http://www.graphviz.org/content/attrs) related to
//! providing layout hints (e.g. left-to-right versus top-down, which
//! algorithm to use, etc). The current intention of this library is to
//! emit a human-readable .dot file with very regular structure suitable
//! for easy post-processing.
//!
//! # Examples
//!
//! The first example uses a very simple graph representation: a list of
//! pairs of ints, representing the edges (the node set is implicit).
//! Each node label is derived directly from the int representing the node,
//! while the edge labels are all empty strings.
//!
//! This example also illustrates how to use `Cow<[T]>` to return
//! an owned vector or a borrowed slice as appropriate: we construct the
//! node vector from scratch, but borrow the edge list (rather than
//! constructing a copy of all the edges from scratch).
//!
//! The output from this example renders five nodes, with the first four
//! forming a diamond-shaped acyclic graph and then pointing to the fifth
//! which is cyclic.
//!
//! ```rust
//! #![feature(rustc_private, core, into_cow)]
//!
//! use std::borrow::IntoCow;
//! use std::io::Write;
//! use graphviz as dot;
//!
//! type Nd = isize;
//! type Ed = (isize,isize);
//! struct Edges(Vec<Ed>);
//!
//! pub fn render_to<W: Write>(output: &mut W) {
//! let edges = Edges(vec!((0,1), (0,2), (1,3), (2,3), (3,4), (4,4)));
//! dot::render(&edges, output).unwrap()
//! }
//!
//! impl<'a> dot::Labeller<'a, Nd, Ed> for Edges {
//! fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example1").unwrap() }
//!
//! fn node_id(&'a self, n: &Nd) -> dot::Id<'a> {
//! dot::Id::new(format!("N{}", *n)).unwrap()
//! }
//! }
//!
//! impl<'a> dot::GraphWalk<'a, Nd, Ed> for Edges {
//! fn nodes(&self) -> dot::Nodes<'a,Nd> {
//! // (assumes that |N| \approxeq |E|)
//! let &Edges(ref v) = self;
//! let mut nodes = Vec::with_capacity(v.len());
//! for &(s,t) in v {
//! nodes.push(s); nodes.push(t);
//! }
//! nodes.sort();
//! nodes.dedup();
//! nodes.into_cow()
//! }
//!
//! fn edges(&'a self) -> dot::Edges<'a,Ed> {
//! let &Edges(ref edges) = self;
//! (&edges[..]).into_cow()
//! }
//!
//! fn source(&self, e: &Ed) -> Nd { let &(s,_) = e; s }
//!
//! fn target(&self, e: &Ed) -> Nd { let &(_,t) = e; t }
//! }
//!
//! # pub fn main() { render_to(&mut Vec::new()) }
//! ```
//!
//! ```no_run
//! # pub fn render_to<W:std::io::Write>(output: &mut W) { unimplemented!() }
//! pub fn main() {
//! use std::fs::File;
//! let mut f = File::create("example1.dot").unwrap();
//! render_to(&mut f)
//! }
//! ```
//!
//! Output from first example (in `example1.dot`):
//!
//! ```ignore
//! digraph example1 {
//! N0[label="N0"];
//! N1[label="N1"];
//! N2[label="N2"];
//! N3[label="N3"];
//! N4[label="N4"];
//! N0 -> N1[label=""];
//! N0 -> N2[label=""];
//! N1 -> N3[label=""];
//! N2 -> N3[label=""];
//! N3 -> N4[label=""];
//! N4 -> N4[label=""];
//! }
//! ```
//!
//! The second example illustrates using `node_label` and `edge_label` to
//! add labels to the nodes and edges in the rendered graph. The graph
//! here carries both `nodes` (the label text to use for rendering a
//! particular node), and `edges` (again a list of `(source,target)`
//! indices).
//!
//! This example also illustrates how to use a type (in this case the edge
//! type) that shares substructure with the graph: the edge type here is a
//! direct reference to the `(source,target)` pair stored in the graph's
//! internal vector (rather than passing around a copy of the pair
//! itself). Note that this implies that `fn edges(&'a self)` must
//! construct a fresh `Vec<&'a (usize,usize)>` from the `Vec<(usize,usize)>`
//! edges stored in `self`.
//!
//! Since both the set of nodes and the set of edges are always
//! constructed from scratch via iterators, we use the `collect()` method
//! from the `Iterator` trait to collect the nodes and edges into freshly
//! constructed growable `Vec` values (rather use the `into_cow`
//! from the `IntoCow` trait as was used in the first example
//! above).
//!
//! The output from this example renders four nodes that make up the
//! Hasse-diagram for the subsets of the set `{x, y}`. Each edge is
//! labelled with the &sube; character (specified using the HTML character
//! entity `&sube`).
//!
//! ```rust
//! #![feature(rustc_private, core, into_cow)]
//!
//! use std::borrow::IntoCow;
//! use std::io::Write;
//! use graphviz as dot;
//!
//! type Nd = usize;
//! type Ed<'a> = &'a (usize, usize);
//! struct Graph { nodes: Vec<&'static str>, edges: Vec<(usize,usize)> }
//!
//! pub fn render_to<W: Write>(output: &mut W) {
//! let nodes = vec!("{x,y}","{x}","{y}","{}");
//! let edges = vec!((0,1), (0,2), (1,3), (2,3));
//! let graph = Graph { nodes: nodes, edges: edges };
//!
//! dot::render(&graph, output).unwrap()
//! }
//!
//! impl<'a> dot::Labeller<'a, Nd, Ed<'a>> for Graph {
//! fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example2").unwrap() }
//! fn node_id(&'a self, n: &Nd) -> dot::Id<'a> {
//! dot::Id::new(format!("N{}", n)).unwrap()
//! }
//! fn node_label<'b>(&'b self, n: &Nd) -> dot::LabelText<'b> {
//! dot::LabelText::LabelStr(self.nodes[*n].as_slice().into_cow())
//! }
//! fn edge_label<'b>(&'b self, _: &Ed) -> dot::LabelText<'b> {
//! dot::LabelText::LabelStr("&sube;".into_cow())
//! }
//! }
//!
//! impl<'a> dot::GraphWalk<'a, Nd, Ed<'a>> for Graph {
//! fn nodes(&self) -> dot::Nodes<'a,Nd> { (0..self.nodes.len()).collect() }
//! fn edges(&'a self) -> dot::Edges<'a,Ed<'a>> { self.edges.iter().collect() }
//! fn source(&self, e: &Ed) -> Nd { let & &(s,_) = e; s }
//! fn target(&self, e: &Ed) -> Nd { let & &(_,t) = e; t }
//! }
//!
//! # pub fn main() { render_to(&mut Vec::new()) }
//! ```
//!
//! ```no_run
//! # pub fn render_to<W:std::io::Write>(output: &mut W) { unimplemented!() }
//! pub fn main() {
//! use std::fs::File;
//! let mut f = File::create("example2.dot").unwrap();
//! render_to(&mut f)
//! }
//! ```
//!
//! The third example is similar to the second, except now each node and
//! edge now carries a reference to the string label for each node as well
//! as that node's index. (This is another illustration of how to share
//! structure with the graph itself, and why one might want to do so.)
//!
//! The output from this example is the same as the second example: the
//! Hasse-diagram for the subsets of the set `{x, y}`.
//!
//! ```rust
//! #![feature(rustc_private, core, into_cow)]
//!
//! use std::borrow::IntoCow;
//! use std::io::Write;
//! use graphviz as dot;
//!
//! type Nd<'a> = (usize, &'a str);
//! type Ed<'a> = (Nd<'a>, Nd<'a>);
//! struct Graph { nodes: Vec<&'static str>, edges: Vec<(usize,usize)> }
//!
//! pub fn render_to<W: Write>(output: &mut W) {
//! let nodes = vec!("{x,y}","{x}","{y}","{}");
//! let edges = vec!((0,1), (0,2), (1,3), (2,3));
//! let graph = Graph { nodes: nodes, edges: edges };
//!
//! dot::render(&graph, output).unwrap()
//! }
//!
//! impl<'a> dot::Labeller<'a, Nd<'a>, Ed<'a>> for Graph {
//! fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new("example3").unwrap() }
//! fn node_id(&'a self, n: &Nd<'a>) -> dot::Id<'a> {
//! dot::Id::new(format!("N{}", n.0)).unwrap()
//! }
//! fn node_label<'b>(&'b self, n: &Nd<'b>) -> dot::LabelText<'b> {
//! let &(i, _) = n;
//! dot::LabelText::LabelStr(self.nodes[i].into_cow())
//! }
//! fn edge_label<'b>(&'b self, _: &Ed<'b>) -> dot::LabelText<'b> {
//! dot::LabelText::LabelStr("&sube;".into_cow())
//! }
//! }
//!
//! impl<'a> dot::GraphWalk<'a, Nd<'a>, Ed<'a>> for Graph {
//! fn nodes(&'a self) -> dot::Nodes<'a,Nd<'a>> {
//! self.nodes.iter().map(|s| &s[..]).enumerate().collect()
//! }
//! fn edges(&'a self) -> dot::Edges<'a,Ed<'a>> {
//! self.edges.iter()
//! .map(|&(i,j)|((i, &self.nodes[i][..]),
//! (j, &self.nodes[j][..])))
//! .collect()
//! }
//! fn source(&self, e: &Ed<'a>) -> Nd<'a> { let &(s,_) = e; s }
//! fn target(&self, e: &Ed<'a>) -> Nd<'a> { let &(_,t) = e; t }
//! }
//!
//! # pub fn main() { render_to(&mut Vec::new()) }
//! ```
//!
//! ```no_run
//! # pub fn render_to<W:std::io::Write>(output: &mut W) { unimplemented!() }
//! pub fn main() {
//! use std::fs::File;
//! let mut f = File::create("example3.dot").unwrap();
//! render_to(&mut f)
//! }
//! ```
//!
//! # References
//!
//! * [Graphviz](http://www.graphviz.org/)
//!
//! * [DOT language](http://www.graphviz.org/doc/info/lang.html)
// Do not remove on snapshot creation. Needed for bootstrap. (Issue #22364)
#![cfg_attr(stage0, feature(custom_attribute))]
#![crate_name = "graphviz"]
#![unstable(feature = "rustc_private")]
#![feature(staged_api)]
#![staged_api]
#![crate_type = "rlib"]
#![crate_type = "dylib"]
#![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
html_root_url = "https://doc.rust-lang.org/nightly/")]
#![feature(into_cow)]
#![feature(str_escape)]
use self::LabelText::*;
use std::borrow::{IntoCow, Cow};
use std::io::prelude::*;
use std::io;
/// The text for a graphviz label on a node or edge.
pub enum LabelText<'a> {
/// This kind of label preserves the text directly as is.
///
/// Occurrences of backslashes (`\`) are escaped, and thus appear
/// as backslashes in the rendered label.
LabelStr(Cow<'a, str>),
/// This kind of label uses the graphviz label escString type:
/// http://www.graphviz.org/content/attrs#kescString
///
/// Occurrences of backslashes (`\`) are not escaped; instead they
/// are interpreted as initiating an escString escape sequence.
///
/// Escape sequences of particular interest: in addition to `\n`
/// to break a line (centering the line preceding the `\n`), there
/// are also the escape sequences `\l` which left-justifies the
/// preceding line and `\r` which right-justifies it.
EscStr(Cow<'a, str>),
}
/// The style for a node or edge.
/// See http://www.graphviz.org/doc/info/attrs.html#k:style for descriptions.
/// Note that some of these are not valid for edges.
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
pub enum Style {
None,
Solid,
Dashed,
Dotted,
Bold,
Rounded,
Diagonals,
Filled,
Striped,
Wedged,
}
impl Style {
pub fn as_slice(self) -> &'static str {
match self {
Style::None => "",
Style::Solid => "solid",
Style::Dashed => "dashed",
Style::Dotted => "dotted",
Style::Bold => "bold",
Style::Rounded => "rounded",
Style::Diagonals => "diagonals",
Style::Filled => "filled",
Style::Striped => "striped",
Style::Wedged => "wedged",
}
}
}
// There is a tension in the design of the labelling API.
//
// For example, I considered making a `Labeller<T>` trait that
// provides labels for `T`, and then making the graph type `G`
// implement `Labeller<Node>` and `Labeller<Edge>`. However, this is
// not possible without functional dependencies. (One could work
// around that, but I did not explore that avenue heavily.)
//
// Another approach that I actually used for a while was to make a
// `Label<Context>` trait that is implemented by the client-specific
// Node and Edge types (as well as an implementation on Graph itself
// for the overall name for the graph). The main disadvantage of this
// second approach (compared to having the `G` type parameter
// implement a Labelling service) that I have encountered is that it
// makes it impossible to use types outside of the current crate
// directly as Nodes/Edges; you need to wrap them in newtype'd
// structs. See e.g. the `No` and `Ed` structs in the examples. (In
// practice clients using a graph in some other crate would need to
// provide some sort of adapter shim over the graph anyway to
// interface with this library).
//
// Another approach would be to make a single `Labeller<N,E>` trait
// that provides three methods (graph_label, node_label, edge_label),
// and then make `G` implement `Labeller<N,E>`. At first this did not
// appeal to me, since I had thought I would need separate methods on
// each data variant for dot-internal identifiers versus user-visible
// labels. However, the identifier/label distinction only arises for
// nodes; graphs themselves only have identifiers, and edges only have
// labels.
//
// So in the end I decided to use the third approach described above.
/// `Id` is a Graphviz `ID`.
pub struct Id<'a> {
name: Cow<'a, str>,
}
impl<'a> Id<'a> {
/// Creates an `Id` named `name`.
///
/// The caller must ensure that the input conforms to an
/// identifier format: it must be a non-empty string made up of
/// alphanumeric or underscore characters, not beginning with a
/// digit (i.e. the regular expression `[a-zA-Z_][a-zA-Z_0-9]*`).
///
/// (Note: this format is a strict subset of the `ID` format
/// defined by the DOT language. This function may change in the
/// future to accept a broader subset, or the entirety, of DOT's
/// `ID` format.)
///
/// Passing an invalid string (containing spaces, brackets,
/// quotes, ...) will return an empty `Err` value.
pub fn new<Name: IntoCow<'a, str>>(name: Name) -> Result<Id<'a>, ()> {
let name = name.into_cow();
{
let mut chars = name.chars();
match chars.next() {
Some(c) if is_letter_or_underscore(c) => { ; },
_ => return Err(())
}
if !chars.all(is_constituent) {
return Err(())
}
}
return Ok(Id{ name: name });
fn is_letter_or_underscore(c: char) -> bool {
in_range('a', c, 'z') || in_range('A', c, 'Z') || c == '_'
}
fn is_constituent(c: char) -> bool {
is_letter_or_underscore(c) || in_range('0', c, '9')
}
fn in_range(low: char, c: char, high: char) -> bool {
low as usize <= c as usize && c as usize <= high as usize
}
}
pub fn as_slice(&'a self) -> &'a str {
&*self.name
}
pub fn name(self) -> Cow<'a, str> {
self.name
}
}
/// Each instance of a type that implements `Label<C>` maps to a
/// unique identifier with respect to `C`, which is used to identify
/// it in the generated .dot file. They can also provide more
/// elaborate (and non-unique) label text that is used in the graphviz
/// rendered output.
/// The graph instance is responsible for providing the DOT compatible
/// identifiers for the nodes and (optionally) rendered labels for the nodes and
/// edges, as well as an identifier for the graph itself.
pub trait Labeller<'a,N,E> {
/// Must return a DOT compatible identifier naming the graph.
fn graph_id(&'a self) -> Id<'a>;
/// Maps `n` to a unique identifier with respect to `self`. The
/// implementer is responsible for ensuring that the returned name
/// is a valid DOT identifier.
fn node_id(&'a self, n: &N) -> Id<'a>;
/// Maps `n` to a label that will be used in the rendered output.
/// The label need not be unique, and may be the empty string; the
/// default is just the output from `node_id`.
fn node_label(&'a self, n: &N) -> LabelText<'a> {
LabelStr(self.node_id(n).name)
}
/// Maps `e` to a label that will be used in the rendered output.
/// The label need not be unique, and may be the empty string; the
/// default is in fact the empty string.
fn edge_label(&'a self, e: &E) -> LabelText<'a> {
let _ignored = e;
LabelStr("".into_cow())
}
/// Maps `n` to a style that will be used in the rendered output.
fn node_style(&'a self, _n: &N) -> Style {
Style::None
}
/// Maps `e` to a style that will be used in the rendered output.
fn edge_style(&'a self, _e: &E) -> Style {
Style::None
}
}
impl<'a> LabelText<'a> {
pub fn label<S:IntoCow<'a, str>>(s: S) -> LabelText<'a> {
LabelStr(s.into_cow())
}
pub fn escaped<S:IntoCow<'a, str>>(s: S) -> LabelText<'a> {
EscStr(s.into_cow())
}
fn escape_char<F>(c: char, mut f: F) where F: FnMut(char) {
match c {
// not escaping \\, since Graphviz escString needs to
// interpret backslashes; see EscStr above.
'\\' => f(c),
_ => for c in c.escape_default() { f(c) }
}
}
fn escape_str(s: &str) -> String {
let mut out = String::with_capacity(s.len());
for c in s.chars() {
LabelText::escape_char(c, |c| out.push(c));
}
out
}
/// Renders text as string suitable for a label in a .dot file.
pub fn escape(&self) -> String {
match self {
&LabelStr(ref s) => s.escape_default(),
&EscStr(ref s) => LabelText::escape_str(&s[..]),
}
}
/// Decomposes content into string suitable for making EscStr that
/// yields same content as self. The result obeys the law
/// render(`lt`) == render(`EscStr(lt.pre_escaped_content())`) for
/// all `lt: LabelText`.
fn pre_escaped_content(self) -> Cow<'a, str> {
match self {
EscStr(s) => s,
LabelStr(s) => if s.contains('\\') {
(&*s).escape_default().into_cow()
} else {
s
},
}
}
/// Puts `prefix` on a line above this label, with a blank line separator.
pub fn prefix_line(self, prefix: LabelText) -> LabelText<'static> {
prefix.suffix_line(self)
}
/// Puts `suffix` on a line below this label, with a blank line separator.
pub fn suffix_line(self, suffix: LabelText) -> LabelText<'static> {
let mut prefix = self.pre_escaped_content().into_owned();
let suffix = suffix.pre_escaped_content();
prefix.push_str(r"\n\n");
prefix.push_str(&suffix[..]);
EscStr(prefix.into_cow())
}
}
pub type Nodes<'a,N> = Cow<'a,[N]>;
pub type Edges<'a,E> = Cow<'a,[E]>;
// (The type parameters in GraphWalk should be associated items,
// when/if Rust supports such.)
/// GraphWalk is an abstraction over a directed graph = (nodes,edges)
/// made up of node handles `N` and edge handles `E`, where each `E`
/// can be mapped to its source and target nodes.
///
/// The lifetime parameter `'a` is exposed in this trait (rather than
/// introduced as a generic parameter on each method declaration) so
/// that a client impl can choose `N` and `E` that have substructure
/// that is bound by the self lifetime `'a`.
///
/// The `nodes` and `edges` method each return instantiations of
/// `Cow<[T]>` to leave implementers the freedom to create
/// entirely new vectors or to pass back slices into internally owned
/// vectors.
pub trait GraphWalk<'a, N, E> {
/// Returns all the nodes in this graph.
fn nodes(&'a self) -> Nodes<'a, N>;
/// Returns all of the edges in this graph.
fn edges(&'a self) -> Edges<'a, E>;
/// The source node for `edge`.
fn source(&'a self, edge: &E) -> N;
/// The target node for `edge`.
fn target(&'a self, edge: &E) -> N;
}
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
pub enum RenderOption {
NoEdgeLabels,
NoNodeLabels,
NoEdgeStyles,
NoNodeStyles,
}
/// Returns vec holding all the default render options.
pub fn default_options() -> Vec<RenderOption> { vec![] }
/// Renders directed graph `g` into the writer `w` in DOT syntax.
/// (Simple wrapper around `render_opts` that passes a default set of options.)
pub fn render<'a, N:Clone+'a, E:Clone+'a, G:Labeller<'a,N,E>+GraphWalk<'a,N,E>, W:Write>(
g: &'a G,
w: &mut W) -> io::Result<()> {
render_opts(g, w, &[])
}
/// Renders directed graph `g` into the writer `w` in DOT syntax.
/// (Main entry point for the library.)
pub fn render_opts<'a, N:Clone+'a, E:Clone+'a, G:Labeller<'a,N,E>+GraphWalk<'a,N,E>, W:Write>(
g: &'a G,
w: &mut W,
options: &[RenderOption]) -> io::Result<()>
{
fn writeln<W:Write>(w: &mut W, arg: &[&str]) -> io::Result<()> {
for &s in arg { try!(w.write_all(s.as_bytes())); }
write!(w, "\n")
}
fn indent<W:Write>(w: &mut W) -> io::Result<()> {
w.write_all(b" ")
}
try!(writeln(w, &["digraph ", g.graph_id().as_slice(), " {"]));
for n in g.nodes().iter() {
try!(indent(w));
let id = g.node_id(n);
let escaped = &g.node_label(n).escape();
let mut text = vec![id.as_slice()];
if !options.contains(&RenderOption::NoNodeLabels) {
text.push("[label=\"");
text.push(escaped);
text.push("\"]");
}
let style = g.node_style(n);
if !options.contains(&RenderOption::NoNodeStyles) && style != Style::None {
text.push("[style=\"");
text.push(style.as_slice());
text.push("\"]");
}
text.push(";");
try!(writeln(w, &text));
}
for e in g.edges().iter() {
let escaped_label = &g.edge_label(e).escape();
try!(indent(w));
let source = g.source(e);
let target = g.target(e);
let source_id = g.node_id(&source);
let target_id = g.node_id(&target);
let mut text = vec![source_id.as_slice(), " -> ", target_id.as_slice()];
if !options.contains(&RenderOption::NoEdgeLabels) {
text.push("[label=\"");
text.push(escaped_label);
text.push("\"]");
}
let style = g.edge_style(e);
if !options.contains(&RenderOption::NoEdgeStyles) && style != Style::None {
text.push("[style=\"");
text.push(style.as_slice());
text.push("\"]");
}
text.push(";");
try!(writeln(w, &text));
}
writeln(w, &["}"])
}
#[cfg(test)]
mod tests {
use self::NodeLabels::*;
use super::{Id, Labeller, Nodes, Edges, GraphWalk, render, Style};
use super::LabelText::{self, LabelStr, EscStr};
use std::io;
use std::io::prelude::*;
use std::borrow::IntoCow;
/// each node is an index in a vector in the graph.
type Node = usize;
struct Edge {
from: usize,
to: usize,
label: &'static str,
style: Style,
}
fn edge(from: usize, to: usize, label: &'static str, style: Style) -> Edge {
Edge { from: from, to: to, label: label, style: style }
}
struct LabelledGraph {
/// The name for this graph. Used for labelling generated `digraph`.
name: &'static str,
/// Each node is an index into `node_labels`; these labels are
/// used as the label text for each node. (The node *names*,
/// which are unique identifiers, are derived from their index
/// in this array.)
///
/// If a node maps to None here, then just use its name as its
/// text.
node_labels: Vec<Option<&'static str>>,
node_styles: Vec<Style>,
/// Each edge relates a from-index to a to-index along with a
/// label; `edges` collects them.
edges: Vec<Edge>,
}
// A simple wrapper around LabelledGraph that forces the labels to
// be emitted as EscStr.
struct LabelledGraphWithEscStrs {
graph: LabelledGraph
}
enum NodeLabels<L> {
AllNodesLabelled(Vec<L>),
UnlabelledNodes(usize),
SomeNodesLabelled(Vec<Option<L>>),
}
type Trivial = NodeLabels<&'static str>;
impl NodeLabels<&'static str> {
fn to_opt_strs(self) -> Vec<Option<&'static str>> {
match self {
UnlabelledNodes(len)
=> vec![None; len],
AllNodesLabelled(lbls)
=> lbls.into_iter().map(
|l|Some(l)).collect(),
SomeNodesLabelled(lbls)
=> lbls.into_iter().collect(),
}
}
fn len(&self) -> usize {
match self {
&UnlabelledNodes(len) => len,
&AllNodesLabelled(ref lbls) => lbls.len(),
&SomeNodesLabelled(ref lbls) => lbls.len(),
}
}
}
impl LabelledGraph {
fn new(name: &'static str,
node_labels: Trivial,
edges: Vec<Edge>,
node_styles: Option<Vec<Style>>) -> LabelledGraph {
let count = node_labels.len();
LabelledGraph {
name: name,
node_labels: node_labels.to_opt_strs(),
edges: edges,
node_styles: match node_styles {
Some(nodes) => nodes,
None => vec![Style::None; count],
}
}
}
}
impl LabelledGraphWithEscStrs {
fn new(name: &'static str,
node_labels: Trivial,
edges: Vec<Edge>) -> LabelledGraphWithEscStrs {
LabelledGraphWithEscStrs {
graph: LabelledGraph::new(name,
node_labels,
edges,
None)
}
}
}
fn id_name<'a>(n: &Node) -> Id<'a> {
Id::new(format!("N{}", *n)).unwrap()
}
impl<'a> Labeller<'a, Node, &'a Edge> for LabelledGraph {
fn graph_id(&'a self) -> Id<'a> {
Id::new(&self.name[..]).unwrap()
}
fn node_id(&'a self, n: &Node) -> Id<'a> {
id_name(n)
}
fn node_label(&'a self, n: &Node) -> LabelText<'a> {
match self.node_labels[*n] {
Some(ref l) => LabelStr(l.into_cow()),
None => LabelStr(id_name(n).name()),
}
}
fn edge_label(&'a self, e: & &'a Edge) -> LabelText<'a> {
LabelStr(e.label.into_cow())
}
fn node_style(&'a self, n: &Node) -> Style {
self.node_styles[*n]
}
fn edge_style(&'a self, e: & &'a Edge) -> Style {
e.style
}
}
impl<'a> Labeller<'a, Node, &'a Edge> for LabelledGraphWithEscStrs {
fn graph_id(&'a self) -> Id<'a> { self.graph.graph_id() }
fn node_id(&'a self, n: &Node) -> Id<'a> { self.graph.node_id(n) }
fn node_label(&'a self, n: &Node) -> LabelText<'a> {
match self.graph.node_label(n) {
LabelStr(s) | EscStr(s) => EscStr(s),
}
}
fn edge_label(&'a self, e: & &'a Edge) -> LabelText<'a> {
match self.graph.edge_label(e) {
LabelStr(s) | EscStr(s) => EscStr(s),
}
}
}
impl<'a> GraphWalk<'a, Node, &'a Edge> for LabelledGraph {
fn nodes(&'a self) -> Nodes<'a,Node> {
(0..self.node_labels.len()).collect()
}
fn edges(&'a self) -> Edges<'a,&'a Edge> {
self.edges.iter().collect()
}
fn source(&'a self, edge: & &'a Edge) -> Node {
edge.from
}
fn target(&'a self, edge: & &'a Edge) -> Node {
edge.to
}
}
impl<'a> GraphWalk<'a, Node, &'a Edge> for LabelledGraphWithEscStrs {
fn nodes(&'a self) -> Nodes<'a,Node> {
self.graph.nodes()
}
fn edges(&'a self) -> Edges<'a,&'a Edge> {
self.graph.edges()
}
fn source(&'a self, edge: & &'a Edge) -> Node {
edge.from
}
fn target(&'a self, edge: & &'a Edge) -> Node {
edge.to
}
}
fn test_input(g: LabelledGraph) -> io::Result<String> {
let mut writer = Vec::new();
render(&g, &mut writer).unwrap();
let mut s = String::new();
try!(Read::read_to_string(&mut &*writer, &mut s));
Ok(s)
}
// All of the tests use raw-strings as the format for the expected outputs,
// so that you can cut-and-paste the content into a .dot file yourself to
// see what the graphviz visualizer would produce.
#[test]
fn empty_graph() {
let labels : Trivial = UnlabelledNodes(0);
let r = test_input(LabelledGraph::new("empty_graph", labels, vec![], None));
assert_eq!(r.unwrap(),
r#"digraph empty_graph {
}
"#);
}
#[test]
fn single_node() {
let labels : Trivial = UnlabelledNodes(1);
let r = test_input(LabelledGraph::new("single_node", labels, vec![], None));
assert_eq!(r.unwrap(),
r#"digraph single_node {
N0[label="N0"];
}
"#);
}
#[test]
fn single_node_with_style() {
let labels : Trivial = UnlabelledNodes(1);
let styles = Some(vec![Style::Dashed]);
let r = test_input(LabelledGraph::new("single_node", labels, vec![], styles));
assert_eq!(r.unwrap(),
r#"digraph single_node {
N0[label="N0"][style="dashed"];
}
"#);
}
#[test]
fn single_edge() {
let labels : Trivial = UnlabelledNodes(2);
let result = test_input(LabelledGraph::new("single_edge", labels,
vec![edge(0, 1, "E", Style::None)], None));
assert_eq!(result.unwrap(),
r#"digraph single_edge {
N0[label="N0"];
N1[label="N1"];
N0 -> N1[label="E"];
}
"#);
}
#[test]
fn single_edge_with_style() {
let labels : Trivial = UnlabelledNodes(2);
let result = test_input(LabelledGraph::new("single_edge", labels,
vec![edge(0, 1, "E", Style::Bold)], None));
assert_eq!(result.unwrap(),
r#"digraph single_edge {
N0[label="N0"];
N1[label="N1"];
N0 -> N1[label="E"][style="bold"];
}
"#);
}
#[test]
fn test_some_labelled() {
let labels : Trivial = SomeNodesLabelled(vec![Some("A"), None]);
let styles = Some(vec![Style::None, Style::Dotted]);
let result = test_input(LabelledGraph::new("test_some_labelled", labels,
vec![edge(0, 1, "A-1", Style::None)], styles));
assert_eq!(result.unwrap(),
r#"digraph test_some_labelled {
N0[label="A"];
N1[label="N1"][style="dotted"];
N0 -> N1[label="A-1"];
}
"#);
}
#[test]
fn single_cyclic_node() {
let labels : Trivial = UnlabelledNodes(1);
let r = test_input(LabelledGraph::new("single_cyclic_node", labels,
vec![edge(0, 0, "E", Style::None)], None));
assert_eq!(r.unwrap(),
r#"digraph single_cyclic_node {
N0[label="N0"];
N0 -> N0[label="E"];
}
"#);
}
#[test]
fn hasse_diagram() {
let labels = AllNodesLabelled(vec!("{x,y}", "{x}", "{y}", "{}"));
let r = test_input(LabelledGraph::new(
"hasse_diagram", labels,
vec![edge(0, 1, "", Style::None), edge(0, 2, "", Style::None),
edge(1, 3, "", Style::None), edge(2, 3, "", Style::None)],
None));
assert_eq!(r.unwrap(),
r#"digraph hasse_diagram {
N0[label="{x,y}"];
N1[label="{x}"];
N2[label="{y}"];
N3[label="{}"];
N0 -> N1[label=""];
N0 -> N2[label=""];
N1 -> N3[label=""];
N2 -> N3[label=""];
}
"#);
}
#[test]
fn left_aligned_text() {
let labels = AllNodesLabelled(vec!(
"if test {\
\\l branch1\
\\l} else {\
\\l branch2\
\\l}\
\\lafterward\
\\l",
"branch1",
"branch2",
"afterward"));
let mut writer = Vec::new();
let g = LabelledGraphWithEscStrs::new(
"syntax_tree", labels,
vec![edge(0, 1, "then", Style::None), edge(0, 2, "else", Style::None),
edge(1, 3, ";", Style::None), edge(2, 3, ";", Style::None)]);
render(&g, &mut writer).unwrap();
let mut r = String::new();
Read::read_to_string(&mut &*writer, &mut r).unwrap();
assert_eq!(r,
r#"digraph syntax_tree {
N0[label="if test {\l branch1\l} else {\l branch2\l}\lafterward\l"];
N1[label="branch1"];
N2[label="branch2"];
N3[label="afterward"];
N0 -> N1[label="then"];
N0 -> N2[label="else"];
N1 -> N3[label=";"];
N2 -> N3[label=";"];
}
"#);
}
#[test]
fn simple_id_construction() {
let id1 = Id::new("hello");
match id1 {
Ok(_) => {;},
Err(..) => panic!("'hello' is not a valid value for id anymore")
}
}
#[test]
fn badly_formatted_id() {
let id2 = Id::new("Weird { struct : ure } !!!");
match id2 {
Ok(_) => panic!("graphviz id suddenly allows spaces, brackets and stuff"),
Err(..) => {;}
}
}
}