././@PaxHeader 0000000 0000000 0000000 00000000034 00000000000 010212 x ustar 00 28 mtime=1676409805.3813572
railroad-diagrams-3.0.1/ 0000755 0321014 0257523 00000000000 00000000000 016411 5 ustar 00tabatkins primarygroup ././@PaxHeader 0000000 0000000 0000000 00000000026 00000000000 010213 x ustar 00 22 mtime=1642540072.0
railroad-diagrams-3.0.1/LICENSE 0000640 0321014 0257523 00000002057 00000000000 017416 0 ustar 00tabatkins primarygroup MIT License
Copyright (c) 2021 Tab Atkins Jr.
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
././@PaxHeader 0000000 0000000 0000000 00000000026 00000000000 010213 x ustar 00 22 mtime=1636495991.0
railroad-diagrams-3.0.1/MANIFEST.in 0000644 0321014 0257523 00000000105 00000000000 020143 0 ustar 00tabatkins primarygroup railroad.py
test.py
railroad-diagrams.css
include *.md
include *.txt
././@PaxHeader 0000000 0000000 0000000 00000000034 00000000000 010212 x ustar 00 28 mtime=1676409805.3813572
railroad-diagrams-3.0.1/PKG-INFO 0000644 0321014 0257523 00000026264 00000000000 017520 0 ustar 00tabatkins primarygroup Metadata-Version: 2.1
Name: railroad-diagrams
Version: 3.0.1
Summary: Generate SVG railroad syntax diagrams, like on JSON.org.
Home-page: https://github.com/tabatkins/railroad-diagrams
Author: Tab Atkins
Author-email: jackalmage@gmail.com
License: UNKNOWN
Keywords: diagrams,syntax,grammar,railroad diagrams
Platform: UNKNOWN
Classifier: License :: OSI Approved :: MIT License
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.7
Requires-Python: >=3.7
Description-Content-Type: text/markdown
License-File: LICENSE
Railroad-Diagram Generator, Python Version
==========================================
This is a small library for generating railroad diagrams
(like what [JSON.org](http://json.org) uses)
using SVG, with both JS and Python ports.
[Here's an online dingus for you to play with and get SVG code from!](https://tabatkins.github.io/railroad-diagrams/generator.html)
(This is the README for the Python port;
see the [main README](https://github.com/tabatkins/railroad-diagrams) for other ports,
and for more non-Python-specific information.)
Diagrams
--------
Constructing a diagram is a set of nested calls:
```python
from railroad import Diagram, Choice
d = Diagram("foo", Choice(0, "bar", "baz"))
d.writeSvg(sys.stdout.write)
```
A railroad diagram must be started as a `Diagram` object,
which takes a list of diagram items,
defined below.
The `Diagram()` constructor also optionally takes some keyword arguments:
* `css`: If passed, is the CSS you would like the diagram to include.
If you don't pass anything, it defaults to including `railroad.DEFAULT_STYLE`.
If you don't want it to include any css at all in the diagram
(perhaps because you're including the `railroad.css` file manually in your page, and don't need each diagram to duplicate the CSS in itself),
pass `css=None`.
* `type`: JSON.org, the inspiration for these diagram's styling, technically has two varieties of Diagrams: a "simple" kind it uses for "leaf" types like numbers, and a "complex" kind which is used for container types like arrays. The only difference is the shape of the start/end indicators of the diagram.
Diagrams default to being "simple", but you can manually choose by passing `type="simple"` or `type="complex"`.
After constructing a Diagram, you can call `.format(...padding)` on it, specifying 0-4 padding values (just like CSS) for some additional "breathing space" around the diagram (the paddings default to 20px).
To output the diagram, call `.writeSvg(cb)` on it, passing a function that'll get called repeatedly to produce the SVG markup. `sys.stdout.write` (or the `.write` property of any file object) is a great value to pass if you're directly outputting it; if you need it as a plain string, a `StringIO` can be used.
This method produces an SVG fragment appropriate to include directly in HTML.
Alternately, you can call `.writeStandalone(cb, css?)`,
which'll format the SVG as a standalone document
rather than as an HTML fragment.
If you don't pass any `css`,
it'll automatically include the `DEFAULT_STYLE`;
you can include your own CSS instead by passing it as a string
(or an empty string to include no CSS at all).
If you need to walk the component tree of a diagram for some reason, `Diagram` has a `.walk(cb)` method as well, which will call your callback on every node in the diagram, in a "pre-order depth-first traversal" (the node first, then each child).
Components
----------
Components are either leaves (containing only text or similar)
or containers (containing other components).
The leaves:
* Terminal(text, href?, title?, cls?) or a bare string - represents literal text.
All arguments past the first are optional:
* 'href' makes the text a hyperlink with the given URL
* 'title' adds an SVG `` element to the element,
giving it "hover text"
and a description for screen-readers and other assistive tech
* 'cls' is additional classes to apply to the element,
beyond the default `'terminal'`
* NonTerminal(text, href) - represents an instruction or another production.
The optional arguments have the same meaning as for Terminal,
except that the default class is `'non-terminal'`.
* Comment(text, href) - a comment.
The optional arguments have the same meaning as for Terminal,
except that the default class is `'non-terminal'`.
* Skip() - an empty line
* Start(type, label) and End(type) - the start/end shapes. These are supplied by default, but if you want to supply a label to the diagram, you can create a Start() explicitly (as the first child of the Diagram!). The "type" attribute takes either "simple" (the default) or "complex", a la Diagram() and ComplexDiagram(). All arguments are optional.
The containers:
* Sequence(...children) - like simple concatenation in a regex.
* Stack(...children) - identical to a Sequence, but the items are stacked vertically rather than horizontally. Best used when a simple Sequence would be too wide; instead, you can break the items up into a Stack of Sequences of an appropriate width.
* OptionalSequence(...children) - a Sequence where every item is *individually* optional, but at least one item must be chosen
* Choice(index, ...children) - like `|` in a regex. The index argument specifies which child is the "normal" choice and should go in the middle (starting from 0 for the first child).
* MultipleChoice(index, type, ...children) - like `||` or `&&` in a CSS grammar; it's similar to a Choice, but more than one branch can be taken. The index argument specifies which child is the "normal" choice and should go in the middle, while the type argument must be either "any" (1+ branches can be taken) or "all" (all branches must be taken).
* HorizontalChoice(...children) - Identical to Choice, but the items are stacked horizontally rather than vertically. There's no "straight-line" choice, so it just takes a list of children. Best used when a simple Choice would be too tall; instead, you can break up the items into a HorizontalChoice of Choices of an appropriate height.
* Optional(child, skip?) - like `?` in a regex. A shorthand for `Choice(1, Skip(), child)`. If the optional `skip` parameter is `True`, it instead puts the Skip() in the straight-line path, for when the "normal" behavior is to omit the item.
* OneOrMore(child, repeat?) - like `+` in a regex. The 'repeat' argument is optional, and specifies something that must go between the repetitions (usually a `Comment()`, but sometimes things like `","`, etc.)
* AlternatingSequence(option1, option2) - similar to a OneOrMore, where you must alternate between the two choices, but allows you to start and end with either element. (OneOrMore requires you to start and end with the "child" node.)
* ZeroOrMore(child, repeat?, skip?) - like `*` in a regex. A shorthand for `Optional(OneOrMore(child, repeat), skip)`. Both `repeat` (same as in `OneOrMore()`) and `skip` (same as in `Optional()`) are optional.
* Group(child, label?) - highlights its child with a dashed outline, and optionally labels it. Passing a string as the label constructs a Comment, or you can build one yourself (to give an href or title).
Options
-------
There are a few options you can tweak, living as UPPERCASE_CONSTANTS at the top of the module; these can be adjusted via `railroad.OPTION_NAME_HERE = "whatever"`.
Note that if you change the text sizes in the CSS,
you'll have to adjust the text metrics here as well.
* VS - sets the minimum amount of vertical separation between two items, in CSS px. Note that the stroke width isn't counted when computing the separation; this shouldn't be relevant unless you have a very small separation or very large stroke width. Defaults to `8`.
* AR - the radius of the arcs, in CSS px, used in the branching containers like Choice. This has a relatively large effect on the size of non-trivial diagrams. Both tight and loose values look good, depending on what you're going for. Defaults to `10`.
* DIAGRAM_CLASS - the class set on the root `<svg>` element of each diagram, for use in the CSS stylesheet. Defaults to `"railroad-diagram"`.
* STROKE_ODD_PIXEL_LENGTH - the default stylesheet uses odd pixel lengths for 'stroke'. Due to rasterization artifacts, they look best when the item has been translated half a pixel in both directions. If you change the styling to use a stroke with even pixel lengths, you'll want to set this variable to `False`.
* INTERNAL_ALIGNMENT - when some branches of a container are narrower than others, this determines how they're aligned in the extra space. Defaults to `"center"`, but can be set to `"left"` or `"right"`.
* CHAR_WIDTH - the approximate width, in CSS px, of characters in normal text (`Terminal` and `NonTerminal`). Defaults to `8.5`.
* COMMENT_CHAR_WIDTH - the approximate width, in CSS px, of character in `Comment` text, which by default is smaller than the other textual items. Defaults to `7`.
* DEBUG - if `True`, writes some additional "debug information" into the attributes of elements in the output, to help debug sizing issues. Defaults to `False`.
././@PaxHeader 0000000 0000000 0000000 00000000026 00000000000 010213 x ustar 00 22 mtime=1656015245.0
railroad-diagrams-3.0.1/README-js.md 0000644 0321014 0257523 00000027123 00000000000 020307 0 ustar 00tabatkins primarygroup Railroad-Diagram Generator, JS Version
=======================================
This is a small library for generating railroad diagrams
(like what [JSON.org](http://json.org) uses)
using SVG, with both JS and Python ports.
[Here's an online dingus for you to play with and get SVG code from!](https://tabatkins.github.io/railroad-diagrams/generator.html)
(This is the README for the JS port;
see the [main README](https://github.com/tabatkins/railroad-diagrams) for other ports,
and for more non-JS-specific information.)
Diagrams
--------
To use the library,
include `railroad.css` in your page,
and import the `railroad.js` module in your script,
then call the Diagram() function.
Its arguments are the components of the diagram
(Diagram is a special form of Sequence).
The constructors for each node are named exports in the module;
the default export is an object of same-named functions that just call the constructors,
so you can construct diagrams without having to spam `new` all over the place:
```js
// Use the constructors
import {Diagram, Choice} from "./railroad.js";
const d = new Diagram("foo", new Choice(0, "bar", "baz"));
// Or use the functions that call the constructors for you
import rr from "./railroad.js";
const d = rr.Diagram("foo", rr.Choice(0, "bar", "baz"));
```
Alternately, you can call ComplexDiagram();
it's identical to Diagram(),
but has slightly different start/end shapes,
same as what JSON.org does to distinguish between "leaf" types like number (ordinary Diagram())
and "container" types like Array (ComplexDiagram()).
The Diagram class also has a few methods:
* `.walk(cb)` calls the cb function on the diagram, then on its child nodes, recursing down the tree. This is a "pre-order depth-first" traversal, if you're into that sort of thing - the first child's children are visited before the diagram's second child. (In other words, the same order you encounter their constructors in the code that created the diagram.) Use this if you want to, say, sanitize things in the diagram.
* `.format(...paddings)` "formats" the Diagram to make it ready for output. Pass it 0-4 paddings, interpreted just like the CSS `padding` property, to give it some "breathing room" around its box; these default to `20` if not specified. This is automatically called by the output functions if you don't do so yourself, so if the default paddings suffice, there's no need to worry about this.
* `.toString()` outputs the SVG of the diagram as a string, ready to be put into your HTML. This is *not* a standalone SVG file; it's intended to be embedded into HTML.
* `.toStandalone()` outputs the SVG of the diagram as a string, but this *is* a standalone SVG file.
* `.toSVG()` outputs the diagram as an actual `<svg>` DOM element, ready for appending into a document.
* `.addTo(parent?)` directly appends the diagram, as an `<svg>` element, to the specified parent element. If you omit the parent element, it instead appends to the script element it's being called from, so you can easily insert a diagram into your document by just dropping a tiny inline `<script>` that just calls `new Diagram(...).addTo()` where you want the diagram to show up.
Components
----------
Components are either leaves or containers.
The leaves:
* `Terminal(text[, {href, title, cls}])` or a bare string - represents literal text.
All the properties in the options bag are optional:
* `href` makes the text a hyperlink with the given URL
* `title` adds an SVG `<title>` element to the element,
giving it "hover text"
and a description for screen-readers and other assistive tech
* `cls` is additional classes to apply to the element,
beyond the default `'terminal'`
* `NonTerminal(text[, {href, title, cls}])` - represents an instruction or another production.
The optional arguments have the same meaning as for Terminal,
except that the default class is `'non-terminal'`.
* `Comment(text[, {href, title, cls}])` - a comment.
The optional arguments have the same meaning as for Terminal,
except that the default class is `'comment'`.
* `Skip()` - an empty line
* `Start({type, label})` and `End({type})` - the start/end shapes. These are supplied by default, but if you want to supply a label to the diagram, you can create a `Start()` explicitly (as the first child of the Diagram!). The `type` property takes either `"simple"` (the default) or `"complex"`, a la `Diagram()` and `ComplexDiagram()`. All properties are optional.
The containers:
* `Sequence(...children)` - like simple concatenation in a regex.
* `Stack(...children)` - identical to a Sequence, but the items are stacked vertically rather than horizontally. Best used when a simple Sequence would be too wide; instead, you can break the items up into a Stack of Sequences of an appropriate width.
* `OptionalSequence(...children)` - a Sequence where every item is *individually* optional, but at least one item must be chosen
* `Choice(index, ...children)` - like `|` in a regex. The index argument specifies which child is the "normal" choice and should go in the middle
* `MultipleChoice(index, type, ...children)` - like `||` or `&&` in a CSS grammar; it's similar to a Choice, but more than one branch can be taken. The index argument specifies which child is the "normal" choice and should go in the middle, while the type argument must be either `"any"` (1+ branches can be taken) or `"all"` (all branches must be taken).
* `HorizontalChoice(...children)` - Identical to Choice, but the items are stacked horizontally rather than vertically. There's no "straight-line" choice, so it just takes a list of children. Best used when a simple Choice would be too tall; instead, you can break up the items into a HorizontalChoice of Choices of an appropriate height.
* `Optional(child[, skip])` - like `?` in a regex. A shorthand for `Choice(1, Skip(), child)`. If the optional `skip` parameter has the value `"skip"`, it instead puts the `Skip()` in the straight-line path, for when the "normal" behavior is to omit the item.
* `OneOrMore(child[, repeat])` - like `+` in a regex. The `repeat` argument is optional, and specifies something that must go between the repetitions (usually a `Comment()`, but sometimes things like `","`, etc.)
* `AlternatingSequence(option1, option2)` - similar to a OneOrMore, where you must alternate between the two choices, but allows you to start and end with either element. (OneOrMore requires you to start and end with the "child" node.)
* `ZeroOrMore(child[, repeat[, skip]])` - like `*` in a regex. A shorthand for `Optional(OneOrMore(child, repeat), skip)`. Both `repeat` (same as in `OneOrMore()`) and `skip` (same as in `Optional()`) are optional.
* `Group(child[, label])` - highlights its child with a dashed outline, and optionally labels it. Passing a string as the label constructs a Comment, or you can build one yourself (to give an href or title).
After constructing a Diagram, call `.format(...padding)` on it, specifying 0-4 padding values (just like CSS) for some additional "breathing space" around the diagram (the paddings default to 20px).
The result can either be `.toString()`'d for the markup, or `.toSVG()`'d for an `<svg>` element, which can then be immediately inserted to the document. As a convenience, Diagram also has an `.addTo(element)` method, which immediately converts it to SVG and appends it to the referenced element with default paddings. `element` defaults to `document.body`.
Options
-------
There are a few options you can tweak,
in an `Options` object exported from the module.
Just tweak either until the diagram looks like what you want.
You can also change the CSS file - feel free to tweak to your heart's content.
Note, though, that if you change the text sizes in the CSS,
you'll have to go adjust the options specifying the text metrics as well.
* `Options.VS` - sets the minimum amount of vertical separation between two items, in CSS px. Note that the stroke width isn't counted when computing the separation; this shouldn't be relevant unless you have a very small separation or very large stroke width. Defaults to `8`.
* `Options.AR` - the radius of the arcs, in CSS px, used in the branching containers like Choice. This has a relatively large effect on the size of non-trivial diagrams. Both tight and loose values look good, depending on what you're going for. Defaults to `10`.
* `Options.DIAGRAM_CLASS` - the class set on the root `<svg>` element of each diagram, for use in the CSS stylesheet. Defaults to `"railroad-diagram"`.
* `Options.STROKE_ODD_PIXEL_LENGTH` - the default stylesheet uses odd pixel lengths for 'stroke'. Due to rasterization artifacts, they look best when the item has been translated half a pixel in both directions. If you change the styling to use a stroke with even pixel lengths, you'll want to set this variable to `False`.
* `Options.INTERNAL_ALIGNMENT` - when some branches of a container are narrower than others, this determines how they're aligned in the extra space. Defaults to `"center"`, but can be set to `"left"` or `"right"`.
* `Options.CHAR_WIDTH` - the approximate width, in CSS px, of characters in normal text (`Terminal` and `NonTerminal`). Defaults to `8.5`.
* `Options.COMMENT_CHAR_WIDTH` - the approximate width, in CSS px, of character in `Comment` text, which by default is smaller than the other textual items. Defaults to `7`.
* `Options.DEBUG` - if `true`, writes some additional "debug information" into the attributes of elements in the output, to help debug sizing issues. Defaults to `false`.
././@PaxHeader 0000000 0000000 0000000 00000000026 00000000000 010213 x ustar 00 22 mtime=1676408421.0
railroad-diagrams-3.0.1/README-py.md 0000644 0321014 0257523 00000025126 00000000000 020324 0 ustar 00tabatkins primarygroup Railroad-Diagram Generator, Python Version
==========================================
This is a small library for generating railroad diagrams
(like what [JSON.org](http://json.org) uses)
using SVG, with both JS and Python ports.
[Here's an online dingus for you to play with and get SVG code from!](https://tabatkins.github.io/railroad-diagrams/generator.html)
(This is the README for the Python port;
see the [main README](https://github.com/tabatkins/railroad-diagrams) for other ports,
and for more non-Python-specific information.)
Diagrams
--------
Constructing a diagram is a set of nested calls:
```python
from railroad import Diagram, Choice
d = Diagram("foo", Choice(0, "bar", "baz"))
d.writeSvg(sys.stdout.write)
```
A railroad diagram must be started as a `Diagram` object,
which takes a list of diagram items,
defined below.
The `Diagram()` constructor also optionally takes some keyword arguments:
* `css`: If passed, is the CSS you would like the diagram to include.
If you don't pass anything, it defaults to including `railroad.DEFAULT_STYLE`.
If you don't want it to include any css at all in the diagram
(perhaps because you're including the `railroad.css` file manually in your page, and don't need each diagram to duplicate the CSS in itself),
pass `css=None`.
* `type`: JSON.org, the inspiration for these diagram's styling, technically has two varieties of Diagrams: a "simple" kind it uses for "leaf" types like numbers, and a "complex" kind which is used for container types like arrays. The only difference is the shape of the start/end indicators of the diagram.
Diagrams default to being "simple", but you can manually choose by passing `type="simple"` or `type="complex"`.
After constructing a Diagram, you can call `.format(...padding)` on it, specifying 0-4 padding values (just like CSS) for some additional "breathing space" around the diagram (the paddings default to 20px).
To output the diagram, call `.writeSvg(cb)` on it, passing a function that'll get called repeatedly to produce the SVG markup. `sys.stdout.write` (or the `.write` property of any file object) is a great value to pass if you're directly outputting it; if you need it as a plain string, a `StringIO` can be used.
This method produces an SVG fragment appropriate to include directly in HTML.
Alternately, you can call `.writeStandalone(cb, css?)`,
which'll format the SVG as a standalone document
rather than as an HTML fragment.
If you don't pass any `css`,
it'll automatically include the `DEFAULT_STYLE`;
you can include your own CSS instead by passing it as a string
(or an empty string to include no CSS at all).
If you need to walk the component tree of a diagram for some reason, `Diagram` has a `.walk(cb)` method as well, which will call your callback on every node in the diagram, in a "pre-order depth-first traversal" (the node first, then each child).
Components
----------
Components are either leaves (containing only text or similar)
or containers (containing other components).
The leaves:
* Terminal(text, href?, title?, cls?) or a bare string - represents literal text.
All arguments past the first are optional:
* 'href' makes the text a hyperlink with the given URL
* 'title' adds an SVG `<title>` element to the element,
giving it "hover text"
and a description for screen-readers and other assistive tech
* 'cls' is additional classes to apply to the element,
beyond the default `'terminal'`
* NonTerminal(text, href) - represents an instruction or another production.
The optional arguments have the same meaning as for Terminal,
except that the default class is `'non-terminal'`.
* Comment(text, href) - a comment.
The optional arguments have the same meaning as for Terminal,
except that the default class is `'non-terminal'`.
* Skip() - an empty line
* Start(type, label) and End(type) - the start/end shapes. These are supplied by default, but if you want to supply a label to the diagram, you can create a Start() explicitly (as the first child of the Diagram!). The "type" attribute takes either "simple" (the default) or "complex", a la Diagram() and ComplexDiagram(). All arguments are optional.
The containers:
* Sequence(...children) - like simple concatenation in a regex.
* Stack(...children) - identical to a Sequence, but the items are stacked vertically rather than horizontally. Best used when a simple Sequence would be too wide; instead, you can break the items up into a Stack of Sequences of an appropriate width.
* OptionalSequence(...children) - a Sequence where every item is *individually* optional, but at least one item must be chosen
* Choice(index, ...children) - like `|` in a regex. The index argument specifies which child is the "normal" choice and should go in the middle (starting from 0 for the first child).
* MultipleChoice(index, type, ...children) - like `||` or `&&` in a CSS grammar; it's similar to a Choice, but more than one branch can be taken. The index argument specifies which child is the "normal" choice and should go in the middle, while the type argument must be either "any" (1+ branches can be taken) or "all" (all branches must be taken).
* HorizontalChoice(...children) - Identical to Choice, but the items are stacked horizontally rather than vertically. There's no "straight-line" choice, so it just takes a list of children. Best used when a simple Choice would be too tall; instead, you can break up the items into a HorizontalChoice of Choices of an appropriate height.
* Optional(child, skip?) - like `?` in a regex. A shorthand for `Choice(1, Skip(), child)`. If the optional `skip` parameter is `True`, it instead puts the Skip() in the straight-line path, for when the "normal" behavior is to omit the item.
* OneOrMore(child, repeat?) - like `+` in a regex. The 'repeat' argument is optional, and specifies something that must go between the repetitions (usually a `Comment()`, but sometimes things like `","`, etc.)
* AlternatingSequence(option1, option2) - similar to a OneOrMore, where you must alternate between the two choices, but allows you to start and end with either element. (OneOrMore requires you to start and end with the "child" node.)
* ZeroOrMore(child, repeat?, skip?) - like `*` in a regex. A shorthand for `Optional(OneOrMore(child, repeat), skip)`. Both `repeat` (same as in `OneOrMore()`) and `skip` (same as in `Optional()`) are optional.
* Group(child, label?) - highlights its child with a dashed outline, and optionally labels it. Passing a string as the label constructs a Comment, or you can build one yourself (to give an href or title).
Options
-------
There are a few options you can tweak, living as UPPERCASE_CONSTANTS at the top of the module; these can be adjusted via `railroad.OPTION_NAME_HERE = "whatever"`.
Note that if you change the text sizes in the CSS,
you'll have to adjust the text metrics here as well.
* VS - sets the minimum amount of vertical separation between two items, in CSS px. Note that the stroke width isn't counted when computing the separation; this shouldn't be relevant unless you have a very small separation or very large stroke width. Defaults to `8`.
* AR - the radius of the arcs, in CSS px, used in the branching containers like Choice. This has a relatively large effect on the size of non-trivial diagrams. Both tight and loose values look good, depending on what you're going for. Defaults to `10`.
* DIAGRAM_CLASS - the class set on the root `<svg>` element of each diagram, for use in the CSS stylesheet. Defaults to `"railroad-diagram"`.
* STROKE_ODD_PIXEL_LENGTH - the default stylesheet uses odd pixel lengths for 'stroke'. Due to rasterization artifacts, they look best when the item has been translated half a pixel in both directions. If you change the styling to use a stroke with even pixel lengths, you'll want to set this variable to `False`.
* INTERNAL_ALIGNMENT - when some branches of a container are narrower than others, this determines how they're aligned in the extra space. Defaults to `"center"`, but can be set to `"left"` or `"right"`.
* CHAR_WIDTH - the approximate width, in CSS px, of characters in normal text (`Terminal` and `NonTerminal`). Defaults to `8.5`.
* COMMENT_CHAR_WIDTH - the approximate width, in CSS px, of character in `Comment` text, which by default is smaller than the other textual items. Defaults to `7`.
* DEBUG - if `True`, writes some additional "debug information" into the attributes of elements in the output, to help debug sizing issues. Defaults to `False`. ././@PaxHeader 0000000 0000000 0000000 00000000026 00000000000 010213 x ustar 00 22 mtime=1642547460.0
railroad-diagrams-3.0.1/README.md 0000644 0321014 0257523 00000004036 00000000000 017673 0 ustar 00tabatkins primarygroup Railroad-diagram Generator
==========================
<a href="https://github.com/tabatkins/railroad-diagrams/blob/gh-pages/images/rr-title.svg"><img src="https://github.com/tabatkins/railroad-diagrams/raw/gh-pages/images/rr-title.svg?sanitize=true" alt="Diagram(Stack('Generate', 'some'), OneOrMore(NonTerminal('railroad diagrams'), Comment('and more')))" title="Diagram(Stack('Generate', 'some'), OneOrMore(NonTerminal('railroad diagrams'), Comment('and more')))" width=10000></a>
This is a small library for generating railroad diagrams
(like what [JSON.org](http://json.org) uses)
using SVG, with both JS and Python ports.
Railroad diagrams are a way of visually representing a grammar
in a form that is more readable than using regular expressions or BNF.
They can easily represent any context-free grammar, and some more powerful grammars.
There are several railroad-diagram generators out there, but none of them had the visual appeal I wanted, so I wrote my own.
[Here's an online dingus for you to play with and get SVG code from!](https://tabatkins.github.io/railroad-diagrams/generator.html)
Versions
--------
This library is supported both as a JS module and a Python module,
and the install and use instructions for each
are in their lang-specific READMEs.
* [JS-specific README](README-js.md)
* [Python-specific README](README-py.md)
Caveats
-------
SVG can't actually respond to the sizes of content; in particular, there's no way to make SVG adjust sizing/positioning based on the length of some text. Instead, I guess at some font metrics, which mostly work as long as you're using a fairly standard monospace font. This works pretty well, but long text inside of a construct might eventually overflow the construct.
License
-------
Standard MIT license; see [LICENSE](LICENSE).
Don't ask me for permission to use any part of this project, **just use it**.
I would appreciate attribution, but that is not required by the license.
If you're doing something cool with it, again I'd appreciate it if you let me know, but that's not required either. ././@PaxHeader 0000000 0000000 0000000 00000000026 00000000000 010213 x ustar 00 22 mtime=1676409756.0
railroad-diagrams-3.0.1/railroad.py 0000644 0321014 0257523 00000137705 00000000000 020575 0 ustar 00tabatkins primarygroup # -*- coding: utf-8 -*-
from __future__ import annotations
import math as Math
import sys
from typing import TYPE_CHECKING
if TYPE_CHECKING:
from typing import (
Any,
Callable,
Dict,
Generator,
List,
Optional as Opt,
Sequence as Seq,
Tuple,
Type,
TypeVar,
Union,
)
T = TypeVar("T")
Node = Union[str, DiagramItem] # pylint: disable=used-before-assignment
WriterF = Callable[[str], Any]
WalkerF = Callable[[DiagramItem], Any] # pylint: disable=used-before-assignment
AttrsT = Dict[str, Any]
# Display constants
DEBUG = False # if true, writes some debug information into attributes
VS = 8 # minimum vertical separation between things. For a 3px stroke, must be at least 4
AR = 10 # radius of arcs
DIAGRAM_CLASS = "railroad-diagram" # class to put on the root <svg>
STROKE_ODD_PIXEL_LENGTH = (
True # is the stroke width an odd (1px, 3px, etc) pixel length?
)
INTERNAL_ALIGNMENT = (
"center" # how to align items when they have extra space. left/right/center
)
CHAR_WIDTH = 8.5 # width of each monospace character. play until you find the right value for your font
COMMENT_CHAR_WIDTH = 7 # comments are in smaller text by default
def escapeAttr(val: Union[str, float]) -> str:
if isinstance(val, str):
return val.replace("&", "&").replace("'", "'").replace('"', """)
return f"{val:g}"
def escapeHtml(val: str) -> str:
return escapeAttr(val).replace("<", "<")
def determineGaps(outer: float, inner: float) -> Tuple[float, float]:
diff = outer - inner
if INTERNAL_ALIGNMENT == "left":
return 0, diff
elif INTERNAL_ALIGNMENT == "right":
return diff, 0
else:
return diff / 2, diff / 2
def doubleenumerate(seq: Seq[T]) -> Generator[Tuple[int, int, T], None, None]:
length = len(list(seq))
for i, item in enumerate(seq):
yield i, i - length, item
def addDebug(el: DiagramItem) -> None:
if not DEBUG:
return
el.attrs["data-x"] = "{0} w:{1} h:{2}/{3}/{4}".format(
type(el).__name__, el.width, el.up, el.height, el.down
)
class DiagramItem:
def __init__(self, name: str, attrs: Opt[AttrsT] = None, text: Opt[Node] = None):
self.name = name
# up = distance it projects above the entry line
self.up: float = 0
# height = distance between the entry/exit lines
self.height: float = 0
# down = distance it projects below the exit line
self.down: float = 0
# width = distance between the entry/exit lines horizontally
self.width: float = 0
# Whether the item is okay with being snug against another item or not
self.needsSpace = False
# DiagramItems pull double duty as SVG elements.
self.attrs: AttrsT = attrs or {}
# Subclasses store their meaningful children as .item or .items;
# .children instead stores their formatted SVG nodes.
self.children: List[Union[Node, Path, Style]] = [text] if text else []
def format(self, x: float, y: float, width: float) -> DiagramItem:
raise NotImplementedError # Virtual
def addTo(self, parent: DiagramItem) -> DiagramItem:
parent.children.append(self)
return self
def writeSvg(self, write: WriterF) -> None:
write("<{0}".format(self.name))
for name, value in sorted(self.attrs.items()):
write(' {0}="{1}"'.format(name, escapeAttr(value)))
write(">")
if self.name in ["g", "svg"]:
write("\n")
for child in self.children:
if isinstance(child, (DiagramItem, Path, Style)):
child.writeSvg(write)
else:
write(escapeHtml(child))
write("</{0}>".format(self.name))
def walk(self, cb: WalkerF) -> None:
cb(self)
class DiagramMultiContainer(DiagramItem):
def __init__(
self,
name: str,
items: Seq[Node],
attrs: Opt[Dict[str, str]] = None,
text: Opt[str] = None,
):
DiagramItem.__init__(self, name, attrs, text)
self.items: List[DiagramItem] = [wrapString(item) for item in items]
def format(self, x: float, y: float, width: float) -> DiagramItem:
raise NotImplementedError # Virtual
def walk(self, cb: WalkerF) -> None:
cb(self)
for item in self.items:
item.walk(cb)
class Path:
def __init__(self, x: float, y: float):
self.x = x
self.y = y
self.attrs = {"d": f"M{x} {y}"}
def m(self, x: float, y: float) -> Path:
self.attrs["d"] += f"m{x} {y}"
return self
def l(self, x: float, y: float) -> Path:
self.attrs["d"] += f"l{x} {y}"
return self
def h(self, val: float) -> Path:
self.attrs["d"] += f"h{val}"
return self
def right(self, val: float) -> Path:
return self.h(max(0, val))
def left(self, val: float) -> Path:
return self.h(-max(0, val))
def v(self, val: float) -> Path:
self.attrs["d"] += f"v{val}"
return self
def down(self, val: float) -> Path:
return self.v(max(0, val))
def up(self, val: float) -> Path:
return self.v(-max(0, val))
def arc_8(self, start: str, dir: str) -> Path:
# 1/8 of a circle
arc = AR
s2 = 1 / Math.sqrt(2) * arc
s2inv = arc - s2
sweep = "1" if dir == "cw" else "0"
path = f"a {arc} {arc} 0 0 {sweep} "
sd = start + dir
offset: List[float]
if sd == "ncw":
offset = [s2, s2inv]
elif sd == "necw":
offset = [s2inv, s2]
elif sd == "ecw":
offset = [-s2inv, s2]
elif sd == "secw":
offset = [-s2, s2inv]
elif sd == "scw":
offset = [-s2, -s2inv]
elif sd == "swcw":
offset = [-s2inv, -s2]
elif sd == "wcw":
offset = [s2inv, -s2]
elif sd == "nwcw":
offset = [s2, -s2inv]
elif sd == "nccw":
offset = [-s2, s2inv]
elif sd == "nwccw":
offset = [-s2inv, s2]
elif sd == "wccw":
offset = [s2inv, s2]
elif sd == "swccw":
offset = [s2, s2inv]
elif sd == "sccw":
offset = [s2, -s2inv]
elif sd == "seccw":
offset = [s2inv, -s2]
elif sd == "eccw":
offset = [-s2inv, -s2]
elif sd == "neccw":
offset = [-s2, -s2inv]
path += " ".join(str(x) for x in offset)
self.attrs["d"] += path
return self
def arc(self, sweep: str) -> Path:
x = AR
y = AR
if sweep[0] == "e" or sweep[1] == "w":
x *= -1
if sweep[0] == "s" or sweep[1] == "n":
y *= -1
cw = 1 if sweep in ("ne", "es", "sw", "wn") else 0
self.attrs["d"] += f"a{AR} {AR} 0 0 {cw} {x} {y}"
return self
def addTo(self, parent: DiagramItem) -> Path:
parent.children.append(self)
return self
def writeSvg(self, write: WriterF) -> None:
write("<path")
for name, value in sorted(self.attrs.items()):
write(f' {name}="{escapeAttr(value)}"')
write(" />")
def format(self) -> Path:
self.attrs["d"] += "h.5"
return self
def __repr__(self) -> str:
return f"Path({repr(self.x)}, {repr(self.y)})"
def wrapString(value: Node) -> DiagramItem:
return value if isinstance(value, DiagramItem) else Terminal(value)
DEFAULT_STYLE = """\
svg.railroad-diagram {
background-color:hsl(30,20%,95%);
}
svg.railroad-diagram path {
stroke-width:3;
stroke:black;
fill:rgba(0,0,0,0);
}
svg.railroad-diagram text {
font:bold 14px monospace;
text-anchor:middle;
}
svg.railroad-diagram text.label{
text-anchor:start;
}
svg.railroad-diagram text.comment{
font:italic 12px monospace;
}
svg.railroad-diagram rect{
stroke-width:3;
stroke:black;
fill:hsl(120,100%,90%);
}
svg.railroad-diagram rect.group-box {
stroke: gray;
stroke-dasharray: 10 5;
fill: none;
}
"""
class Style:
def __init__(self, css: str):
self.css = css
def __repr__(self) -> str:
return f"Style({repr(self.css)})"
def addTo(self, parent: DiagramItem) -> Style:
parent.children.append(self)
return self
def format(self) -> Style:
return self
def writeSvg(self, write: WriterF) -> None:
# Write included stylesheet as CDATA. See https:#developer.mozilla.org/en-US/docs/Web/SVG/Element/style
cdata = "/* <![CDATA[ */\n{css}\n/* ]]> */\n".format(css=self.css)
write("<style>{cdata}</style>".format(cdata=cdata))
class Diagram(DiagramMultiContainer):
def __init__(self, *items: Node, **kwargs: str):
# Accepts a type=[simple|complex] kwarg
DiagramMultiContainer.__init__(
self,
"svg",
list(items),
{
"class": DIAGRAM_CLASS,
},
)
self.type = kwargs.get("type", "simple")
if items and not isinstance(items[0], Start):
self.items.insert(0, Start(self.type))
if items and not isinstance(items[-1], End):
self.items.append(End(self.type))
self.up = 0
self.down = 0
self.height = 0
self.width = 0
for item in self.items:
if isinstance(item, Style):
continue
self.width += item.width + (20 if item.needsSpace else 0)
self.up = max(self.up, item.up - self.height)
self.height += item.height
self.down = max(self.down - item.height, item.down)
if self.items[0].needsSpace:
self.width -= 10
if self.items[-1].needsSpace:
self.width -= 10
self.formatted = False
def __repr__(self) -> str:
items = ", ".join(map(repr, self.items[1:-1]))
pieces = [] if not items else [items]
if self.type != "simple":
pieces.append(f"type={repr(self.type)}")
return f'Diagram({", ".join(pieces)})'
def format(
self,
paddingTop: float = 20,
paddingRight: Opt[float] = None,
paddingBottom: Opt[float] = None,
paddingLeft: Opt[float] = None,
) -> Diagram:
if paddingRight is None:
paddingRight = paddingTop
if paddingBottom is None:
paddingBottom = paddingTop
if paddingLeft is None:
paddingLeft = paddingRight
assert paddingRight is not None
assert paddingBottom is not None
assert paddingLeft is not None
x = paddingLeft
y = paddingTop + self.up
g = DiagramItem("g")
if STROKE_ODD_PIXEL_LENGTH:
g.attrs["transform"] = "translate(.5 .5)"
for item in self.items:
if item.needsSpace:
Path(x, y).h(10).addTo(g)
x += 10
item.format(x, y, item.width).addTo(g)
x += item.width
y += item.height
if item.needsSpace:
Path(x, y).h(10).addTo(g)
x += 10
self.attrs["width"] = str(self.width + paddingLeft + paddingRight)
self.attrs["height"] = str(
self.up + self.height + self.down + paddingTop + paddingBottom
)
self.attrs["viewBox"] = f"0 0 {self.attrs['width']} {self.attrs['height']}"
g.addTo(self)
self.formatted = True
return self
def writeSvg(self, write: WriterF) -> None:
if not self.formatted:
self.format()
return DiagramItem.writeSvg(self, write)
def writeStandalone(self, write: WriterF, css: str|None = None) -> None:
if not self.formatted:
self.format()
if css is None:
css = DEFAULT_STYLE
Style(css).addTo(self)
self.attrs["xmlns"] = "http://www.w3.org/2000/svg"
self.attrs['xmlns:xlink'] = "http://www.w3.org/1999/xlink"
DiagramItem.writeSvg(self, write)
self.children.pop()
del self.attrs["xmlns"]
del self.attrs["xmlns:xlink"]
class Sequence(DiagramMultiContainer):
def __init__(self, *items: Node):
DiagramMultiContainer.__init__(self, "g", items)
self.needsSpace = True
self.up = 0
self.down = 0
self.height = 0
self.width = 0
for item in self.items:
self.width += item.width + (20 if item.needsSpace else 0)
self.up = max(self.up, item.up - self.height)
self.height += item.height
self.down = max(self.down - item.height, item.down)
if self.items[0].needsSpace:
self.width -= 10
if self.items[-1].needsSpace:
self.width -= 10
addDebug(self)
def __repr__(self) -> str:
items = ", ".join(repr(item) for item in self.items)
return f"Sequence({items})"
def format(self, x: float, y: float, width: float) -> Sequence:
leftGap, rightGap = determineGaps(width, self.width)
Path(x, y).h(leftGap).addTo(self)
Path(x + leftGap + self.width, y + self.height).h(rightGap).addTo(self)
x += leftGap
for i, item in enumerate(self.items):
if item.needsSpace and i > 0:
Path(x, y).h(10).addTo(self)
x += 10
item.format(x, y, item.width).addTo(self)
x += item.width
y += item.height
if item.needsSpace and i < len(self.items) - 1:
Path(x, y).h(10).addTo(self)
x += 10
return self
class Stack(DiagramMultiContainer):
def __init__(self, *items: Node):
DiagramMultiContainer.__init__(self, "g", items)
self.needsSpace = True
self.width = max(
item.width + (20 if item.needsSpace else 0) for item in self.items
)
# pretty sure that space calc is totes wrong
if len(self.items) > 1:
self.width += AR * 2
self.up = self.items[0].up
self.down = self.items[-1].down
self.height = 0
last = len(self.items) - 1
for i, item in enumerate(self.items):
self.height += item.height
if i > 0:
self.height += max(AR * 2, item.up + VS)
if i < last:
self.height += max(AR * 2, item.down + VS)
addDebug(self)
def __repr__(self) -> str:
items = ", ".join(repr(item) for item in self.items)
return f"Stack({items})"
def format(self, x: float, y: float, width: float) -> Stack:
leftGap, rightGap = determineGaps(width, self.width)
Path(x, y).h(leftGap).addTo(self)
x += leftGap
xInitial = x
if len(self.items) > 1:
Path(x, y).h(AR).addTo(self)
x += AR
innerWidth = self.width - AR * 2
else:
innerWidth = self.width
for i, item in enumerate(self.items):
item.format(x, y, innerWidth).addTo(self)
x += innerWidth
y += item.height
if i != len(self.items) - 1:
(
Path(x, y)
.arc("ne")
.down(max(0, item.down + VS - AR * 2))
.arc("es")
.left(innerWidth)
.arc("nw")
.down(max(0, self.items[i + 1].up + VS - AR * 2))
.arc("ws")
.addTo(self)
)
y += max(item.down + VS, AR * 2) + max(
self.items[i + 1].up + VS, AR * 2
)
x = xInitial + AR
if len(self.items) > 1:
Path(x, y).h(AR).addTo(self)
x += AR
Path(x, y).h(rightGap).addTo(self)
return self
class OptionalSequence(DiagramMultiContainer):
def __new__(cls, *items: Node) -> Any:
if len(items) <= 1:
return Sequence(*items)
else:
return super(OptionalSequence, cls).__new__(cls)
def __init__(self, *items: Node):
DiagramMultiContainer.__init__(self, "g", items)
self.needsSpace = False
self.width = 0
self.up = 0
self.height = sum(item.height for item in self.items)
self.down = self.items[0].down
heightSoFar: float = 0
for i, item in enumerate(self.items):
self.up = max(self.up, max(AR * 2, item.up + VS) - heightSoFar)
heightSoFar += item.height
if i > 0:
self.down = (
max(
self.height + self.down,
heightSoFar + max(AR * 2, item.down + VS),
)
- self.height
)
itemWidth = item.width + (10 if item.needsSpace else 0)
if i == 0:
self.width += AR + max(itemWidth, AR)
else:
self.width += AR * 2 + max(itemWidth, AR) + AR
addDebug(self)
def __repr__(self) -> str:
items = ", ".join(repr(item) for item in self.items)
return f"OptionalSequence({items})"
def format(self, x: float, y: float, width: float) -> OptionalSequence:
leftGap, rightGap = determineGaps(width, self.width)
Path(x, y).right(leftGap).addTo(self)
Path(x + leftGap + self.width, y + self.height).right(rightGap).addTo(self)
x += leftGap
upperLineY = y - self.up
last = len(self.items) - 1
for i, item in enumerate(self.items):
itemSpace = 10 if item.needsSpace else 0
itemWidth = item.width + itemSpace
if i == 0:
# Upper skip
(
Path(x, y)
.arc("se")
.up(y - upperLineY - AR * 2)
.arc("wn")
.right(itemWidth - AR)
.arc("ne")
.down(y + item.height - upperLineY - AR * 2)
.arc("ws")
.addTo(self)
)
# Straight line
(Path(x, y).right(itemSpace + AR).addTo(self))
item.format(x + itemSpace + AR, y, item.width).addTo(self)
x += itemWidth + AR
y += item.height
elif i < last:
# Upper skip
(
Path(x, upperLineY)
.right(AR * 2 + max(itemWidth, AR) + AR)
.arc("ne")
.down(y - upperLineY + item.height - AR * 2)
.arc("ws")
.addTo(self)
)
# Straight line
(Path(x, y).right(AR * 2).addTo(self))
item.format(x + AR * 2, y, item.width).addTo(self)
(
Path(x + item.width + AR * 2, y + item.height)
.right(itemSpace + AR)
.addTo(self)
)
# Lower skip
(
Path(x, y)
.arc("ne")
.down(item.height + max(item.down + VS, AR * 2) - AR * 2)
.arc("ws")
.right(itemWidth - AR)
.arc("se")
.up(item.down + VS - AR * 2)
.arc("wn")
.addTo(self)
)
x += AR * 2 + max(itemWidth, AR) + AR
y += item.height
else:
# Straight line
(Path(x, y).right(AR * 2).addTo(self))
item.format(x + AR * 2, y, item.width).addTo(self)
(
Path(x + AR * 2 + item.width, y + item.height)
.right(itemSpace + AR)
.addTo(self)
)
# Lower skip
(
Path(x, y)
.arc("ne")
.down(item.height + max(item.down + VS, AR * 2) - AR * 2)
.arc("ws")
.right(itemWidth - AR)
.arc("se")
.up(item.down + VS - AR * 2)
.arc("wn")
.addTo(self)
)
return self
class AlternatingSequence(DiagramMultiContainer):
def __new__(cls, *items: Node) -> AlternatingSequence:
if len(items) == 2:
return super(AlternatingSequence, cls).__new__(cls)
else:
raise Exception(
"AlternatingSequence takes exactly two arguments, but got {0} arguments.".format(
len(items)
)
)
def __init__(self, *items: Node):
DiagramMultiContainer.__init__(self, "g", items)
self.needsSpace = False
arc = AR
vert = VS
first = self.items[0]
second = self.items[1]
arcX = 1 / Math.sqrt(2) * arc * 2
arcY = (1 - 1 / Math.sqrt(2)) * arc * 2
crossY = max(arc, vert)
crossX = (crossY - arcY) + arcX
firstOut = max(
arc + arc, crossY / 2 + arc + arc, crossY / 2 + vert + first.down
)
self.up = firstOut + first.height + first.up
secondIn = max(arc + arc, crossY / 2 + arc + arc, crossY / 2 + vert + second.up)
self.down = secondIn + second.height + second.down
self.height = 0
firstWidth = (20 if first.needsSpace else 0) + first.width
secondWidth = (20 if second.needsSpace else 0) + second.width
self.width = 2 * arc + max(firstWidth, crossX, secondWidth) + 2 * arc
addDebug(self)
def __repr__(self) -> str:
items = ", ".join(repr(item) for item in self.items)
return f"AlternatingSequence({items})"
def format(self, x: float, y: float, width: float) -> AlternatingSequence:
arc = AR
gaps = determineGaps(width, self.width)
Path(x, y).right(gaps[0]).addTo(self)
x += gaps[0]
Path(x + self.width, y).right(gaps[1]).addTo(self)
# bounding box
# Path(x+gaps[0], y).up(self.up).right(self.width).down(self.up+self.down).left(self.width).up(self.down).addTo(self)
first = self.items[0]
second = self.items[1]
# top
firstIn = self.up - first.up
firstOut = self.up - first.up - first.height
Path(x, y).arc("se").up(firstIn - 2 * arc).arc("wn").addTo(self)
first.format(x + 2 * arc, y - firstIn, self.width - 4 * arc).addTo(self)
Path(x + self.width - 2 * arc, y - firstOut).arc("ne").down(
firstOut - 2 * arc
).arc("ws").addTo(self)
# bottom
secondIn = self.down - second.down - second.height
secondOut = self.down - second.down
Path(x, y).arc("ne").down(secondIn - 2 * arc).arc("ws").addTo(self)
second.format(x + 2 * arc, y + secondIn, self.width - 4 * arc).addTo(self)
Path(x + self.width - 2 * arc, y + secondOut).arc("se").up(
secondOut - 2 * arc
).arc("wn").addTo(self)
# crossover
arcX = 1 / Math.sqrt(2) * arc * 2
arcY = (1 - 1 / Math.sqrt(2)) * arc * 2
crossY = max(arc, VS)
crossX = (crossY - arcY) + arcX
crossBar = (self.width - 4 * arc - crossX) / 2
(
Path(x + arc, y - crossY / 2 - arc)
.arc("ws")
.right(crossBar)
.arc_8("n", "cw")
.l(crossX - arcX, crossY - arcY)
.arc_8("sw", "ccw")
.right(crossBar)
.arc("ne")
.addTo(self)
)
(
Path(x + arc, y + crossY / 2 + arc)
.arc("wn")
.right(crossBar)
.arc_8("s", "ccw")
.l(crossX - arcX, -(crossY - arcY))
.arc_8("nw", "cw")
.right(crossBar)
.arc("se")
.addTo(self)
)
return self
class Choice(DiagramMultiContainer):
def __init__(self, default: int, *items: Node):
DiagramMultiContainer.__init__(self, "g", items)
assert default < len(items)
self.default = default
self.width = AR * 4 + max(item.width for item in self.items)
self.up = self.items[0].up
self.down = self.items[-1].down
self.height = self.items[default].height
for i, item in enumerate(self.items):
if i in [default - 1, default + 1]:
arcs = AR * 2
else:
arcs = AR
if i < default:
self.up += max(
arcs, item.height + item.down + VS + self.items[i + 1].up
)
elif i == default:
continue
else:
self.down += max(
arcs,
item.up + VS + self.items[i - 1].down + self.items[i - 1].height,
)
self.down -= self.items[default].height # already counted in self.height
addDebug(self)
def __repr__(self) -> str:
items = ", ".join(repr(item) for item in self.items)
return "Choice(%r, %s)" % (self.default, items)
def format(self, x: float, y: float, width: float) -> Choice:
leftGap, rightGap = determineGaps(width, self.width)
# Hook up the two sides if self is narrower than its stated width.
Path(x, y).h(leftGap).addTo(self)
Path(x + leftGap + self.width, y + self.height).h(rightGap).addTo(self)
x += leftGap
innerWidth = self.width - AR * 4
default = self.items[self.default]
# Do the elements that curve above
above = self.items[: self.default][::-1]
if above:
distanceFromY = max(
AR * 2, default.up + VS + above[0].down + above[0].height
)
for i, ni, item in doubleenumerate(above):
Path(x, y).arc("se").up(distanceFromY - AR * 2).arc("wn").addTo(self)
item.format(x + AR * 2, y - distanceFromY, innerWidth).addTo(self)
Path(x + AR * 2 + innerWidth, y - distanceFromY + item.height).arc(
"ne"
).down(distanceFromY - item.height + default.height - AR * 2).arc(
"ws"
).addTo(
self
)
if ni < -1:
distanceFromY += max(
AR, item.up + VS + above[i + 1].down + above[i + 1].height
)
# Do the straight-line path.
Path(x, y).right(AR * 2).addTo(self)
self.items[self.default].format(x + AR * 2, y, innerWidth).addTo(self)
Path(x + AR * 2 + innerWidth, y + self.height).right(AR * 2).addTo(self)
# Do the elements that curve below
below = self.items[self.default + 1 :]
if below:
distanceFromY = max(
AR * 2, default.height + default.down + VS + below[0].up
)
for i, item in enumerate(below):
Path(x, y).arc("ne").down(distanceFromY - AR * 2).arc("ws").addTo(self)
item.format(x + AR * 2, y + distanceFromY, innerWidth).addTo(self)
Path(x + AR * 2 + innerWidth, y + distanceFromY + item.height).arc("se").up(
distanceFromY - AR * 2 + item.height - default.height
).arc("wn").addTo(self)
distanceFromY += max(
AR,
item.height
+ item.down
+ VS
+ (below[i + 1].up if i + 1 < len(below) else 0),
)
return self
class MultipleChoice(DiagramMultiContainer):
def __init__(self, default: int, type: str, *items: Node):
DiagramMultiContainer.__init__(self, "g", items)
assert 0 <= default < len(items)
assert type in ["any", "all"]
self.default = default
self.type = type
self.needsSpace = True
self.innerWidth = max(item.width for item in self.items)
self.width = 30 + AR + self.innerWidth + AR + 20
self.up = self.items[0].up
self.down = self.items[-1].down
self.height = self.items[default].height
for i, item in enumerate(self.items):
if i in [default - 1, default + 1]:
minimum = 10 + AR
else:
minimum = AR
if i < default:
self.up += max(
minimum, item.height + item.down + VS + self.items[i + 1].up
)
elif i == default:
continue
else:
self.down += max(
minimum,
item.up + VS + self.items[i - 1].down + self.items[i - 1].height,
)
self.down -= self.items[default].height # already counted in self.height
addDebug(self)
def __repr__(self) -> str:
items = ", ".join(repr(item) for item in self.items)
return f"MultipleChoice({repr(self.default)}, {repr(self.type)}, {items})"
def format(self, x: float, y: float, width: float) -> MultipleChoice:
leftGap, rightGap = determineGaps(width, self.width)
# Hook up the two sides if self is narrower than its stated width.
Path(x, y).h(leftGap).addTo(self)
Path(x + leftGap + self.width, y + self.height).h(rightGap).addTo(self)
x += leftGap
default = self.items[self.default]
# Do the elements that curve above
above = self.items[: self.default][::-1]
if above:
distanceFromY = max(
10 + AR, default.up + VS + above[0].down + above[0].height
)
for i, ni, item in doubleenumerate(above):
(Path(x + 30, y).up(distanceFromY - AR).arc("wn").addTo(self))
item.format(x + 30 + AR, y - distanceFromY, self.innerWidth).addTo(self)
(
Path(x + 30 + AR + self.innerWidth, y - distanceFromY + item.height)
.arc("ne")
.down(distanceFromY - item.height + default.height - AR - 10)
.addTo(self)
)
if ni < -1:
distanceFromY += max(
AR, item.up + VS + above[i + 1].down + above[i + 1].height
)
# Do the straight-line path.
Path(x + 30, y).right(AR).addTo(self)
self.items[self.default].format(x + 30 + AR, y, self.innerWidth).addTo(self)
Path(x + 30 + AR + self.innerWidth, y + self.height).right(AR).addTo(self)
# Do the elements that curve below
below = self.items[self.default + 1 :]
if below:
distanceFromY = max(
10 + AR, default.height + default.down + VS + below[0].up
)
for i, item in enumerate(below):
(Path(x + 30, y).down(distanceFromY - AR).arc("ws").addTo(self))
item.format(x + 30 + AR, y + distanceFromY, self.innerWidth).addTo(self)
(
Path(x + 30 + AR + self.innerWidth, y + distanceFromY + item.height)
.arc("se")
.up(distanceFromY - AR + item.height - default.height - 10)
.addTo(self)
)
distanceFromY += max(
AR,
item.height
+ item.down
+ VS
+ (below[i + 1].up if i + 1 < len(below) else 0),
)
text = DiagramItem("g", attrs={"class": "diagram-text"}).addTo(self)
DiagramItem(
"title",
text="take one or more branches, once each, in any order"
if self.type == "any"
else "take all branches, once each, in any order",
).addTo(text)
DiagramItem(
"path",
attrs={
"d": "M {x} {y} h -26 a 4 4 0 0 0 -4 4 v 12 a 4 4 0 0 0 4 4 h 26 z".format(
x=x + 30, y=y - 10
),
"class": "diagram-text",
},
).addTo(text)
DiagramItem(
"text",
text="1+" if self.type == "any" else "all",
attrs={"x": x + 15, "y": y + 4, "class": "diagram-text"},
).addTo(text)
DiagramItem(
"path",
attrs={
"d": "M {x} {y} h 16 a 4 4 0 0 1 4 4 v 12 a 4 4 0 0 1 -4 4 h -16 z".format(
x=x + self.width - 20, y=y - 10
),
"class": "diagram-text",
},
).addTo(text)
DiagramItem(
"text",
text="↺",
attrs={"x": x + self.width - 10, "y": y + 4, "class": "diagram-arrow"},
).addTo(text)
return self
class HorizontalChoice(DiagramMultiContainer):
def __new__(cls, *items: Node) -> Any:
if len(items) <= 1:
return Sequence(*items)
else:
return super(HorizontalChoice, cls).__new__(cls)
def __init__(self, *items: Node):
DiagramMultiContainer.__init__(self, "g", items)
allButLast = self.items[:-1]
middles = self.items[1:-1]
first = self.items[0]
last = self.items[-1]
self.needsSpace = False
self.width = (
AR # starting track
+ AR * 2 * (len(self.items) - 1) # inbetween tracks
+ sum(x.width + (20 if x.needsSpace else 0) for x in self.items) # items
+ (AR if last.height > 0 else 0) # needs space to curve up
+ AR
) # ending track
# Always exits at entrance height
self.height = 0
# All but the last have a track running above them
self._upperTrack = max(AR * 2, VS, max(x.up for x in allButLast) + VS)
self.up = max(self._upperTrack, last.up)
# All but the first have a track running below them
# Last either straight-lines or curves up, so has different calculation
self._lowerTrack = max(
VS,
max(x.height + max(x.down + VS, AR * 2) for x in middles) if middles else 0,
last.height + last.down + VS,
)
if first.height < self._lowerTrack:
# Make sure there's at least 2*AR room between first exit and lower track
self._lowerTrack = max(self._lowerTrack, first.height + AR * 2)
self.down = max(self._lowerTrack, first.height + first.down)
addDebug(self)
def format(self, x: float, y: float, width: float) -> HorizontalChoice:
# Hook up the two sides if self is narrower than its stated width.
leftGap, rightGap = determineGaps(width, self.width)
Path(x, y).h(leftGap).addTo(self)
Path(x + leftGap + self.width, y + self.height).h(rightGap).addTo(self)
x += leftGap
first = self.items[0]
last = self.items[-1]
# upper track
upperSpan = (
sum(x.width + (20 if x.needsSpace else 0) for x in self.items[:-1])
+ (len(self.items) - 2) * AR * 2
- AR
)
(
Path(x, y)
.arc("se")
.up(self._upperTrack - AR * 2)
.arc("wn")
.h(upperSpan)
.addTo(self)
)
# lower track
lowerSpan = (
sum(x.width + (20 if x.needsSpace else 0) for x in self.items[1:])
+ (len(self.items) - 2) * AR * 2
+ (AR if last.height > 0 else 0)
- AR
)
lowerStart = x + AR + first.width + (20 if first.needsSpace else 0) + AR * 2
(
Path(lowerStart, y + self._lowerTrack)
.h(lowerSpan)
.arc("se")
.up(self._lowerTrack - AR * 2)
.arc("wn")
.addTo(self)
)
# Items
for [i, item] in enumerate(self.items):
# input track
if i == 0:
(Path(x, y).h(AR).addTo(self))
x += AR
else:
(
Path(x, y - self._upperTrack)
.arc("ne")
.v(self._upperTrack - AR * 2)
.arc("ws")
.addTo(self)
)
x += AR * 2
# item
itemWidth = item.width + (20 if item.needsSpace else 0)
item.format(x, y, itemWidth).addTo(self)
x += itemWidth
# output track
if i == len(self.items) - 1:
if item.height == 0:
(Path(x, y).h(AR).addTo(self))
else:
(Path(x, y + item.height).arc("se").addTo(self))
elif i == 0 and item.height > self._lowerTrack:
# Needs to arc up to meet the lower track, not down.
if item.height - self._lowerTrack >= AR * 2:
(
Path(x, y + item.height)
.arc("se")
.v(self._lowerTrack - item.height + AR * 2)
.arc("wn")
.addTo(self)
)
else:
# Not enough space to fit two arcs
# so just bail and draw a straight line for now.
(
Path(x, y + item.height)
.l(AR * 2, self._lowerTrack - item.height)
.addTo(self)
)
else:
(
Path(x, y + item.height)
.arc("ne")
.v(self._lowerTrack - item.height - AR * 2)
.arc("ws")
.addTo(self)
)
return self
def Optional(item: Node, skip: bool = False) -> Choice:
return Choice(0 if skip else 1, Skip(), item)
class OneOrMore(DiagramItem):
def __init__(self, item: Node, repeat: Opt[Node] = None):
DiagramItem.__init__(self, "g")
self.item = wrapString(item)
repeat = repeat or Skip()
self.rep = wrapString(repeat)
self.width = max(self.item.width, self.rep.width) + AR * 2
self.height = self.item.height
self.up = self.item.up
self.down = max(
AR * 2, self.item.down + VS + self.rep.up + self.rep.height + self.rep.down
)
self.needsSpace = True
addDebug(self)
def format(self, x: float, y: float, width: float) -> OneOrMore:
leftGap, rightGap = determineGaps(width, self.width)
# Hook up the two sides if self is narrower than its stated width.
Path(x, y).h(leftGap).addTo(self)
Path(x + leftGap + self.width, y + self.height).h(rightGap).addTo(self)
x += leftGap
# Draw item
Path(x, y).right(AR).addTo(self)
self.item.format(x + AR, y, self.width - AR * 2).addTo(self)
Path(x + self.width - AR, y + self.height).right(AR).addTo(self)
# Draw repeat arc
distanceFromY = max(
AR * 2, self.item.height + self.item.down + VS + self.rep.up
)
Path(x + AR, y).arc("nw").down(distanceFromY - AR * 2).arc("ws").addTo(self)
self.rep.format(x + AR, y + distanceFromY, self.width - AR * 2).addTo(self)
Path(x + self.width - AR, y + distanceFromY + self.rep.height).arc("se").up(
distanceFromY - AR * 2 + self.rep.height - self.item.height
).arc("en").addTo(self)
return self
def walk(self, cb: WalkerF) -> None:
cb(self)
self.item.walk(cb)
self.rep.walk(cb)
def __repr__(self) -> str:
return f"OneOrMore({repr(self.item)}, repeat={repr(self.rep)})"
def ZeroOrMore(item: Node, repeat: Opt[Node] = None, skip: bool = False) -> Choice:
result = Optional(OneOrMore(item, repeat), skip)
return result
class Group(DiagramItem):
def __init__(self, item: Node, label: Opt[Node] = None):
DiagramItem.__init__(self, "g")
self.item = wrapString(item)
self.label: Opt[DiagramItem]
if isinstance(label, DiagramItem):
self.label = label
elif label:
self.label = Comment(label)
else:
self.label = None
self.width = max(
self.item.width + (20 if self.item.needsSpace else 0),
self.label.width if self.label else 0,
AR * 2,
)
self.height = self.item.height
self.boxUp = max(self.item.up + VS, AR)
self.up = self.boxUp
if self.label:
self.up += self.label.up + self.label.height + self.label.down
self.down = max(self.item.down + VS, AR)
self.needsSpace = True
addDebug(self)
def format(self, x: float, y: float, width: float) -> Group:
leftGap, rightGap = determineGaps(width, self.width)
Path(x, y).h(leftGap).addTo(self)
Path(x + leftGap + self.width, y + self.height).h(rightGap).addTo(self)
x += leftGap
DiagramItem(
"rect",
{
"x": x,
"y": y - self.boxUp,
"width": self.width,
"height": self.boxUp + self.height + self.down,
"rx": AR,
"ry": AR,
"class": "group-box",
},
).addTo(self)
self.item.format(x, y, self.width).addTo(self)
if self.label:
self.label.format(
x,
y - (self.boxUp + self.label.down + self.label.height),
self.label.width,
).addTo(self)
return self
def walk(self, cb: WalkerF) -> None:
cb(self)
self.item.walk(cb)
if self.label:
self.label.walk(cb)
class Start(DiagramItem):
def __init__(self, type: str = "simple", label: Opt[str] = None):
DiagramItem.__init__(self, "g")
if label:
self.width = max(20, len(label) * CHAR_WIDTH + 10)
else:
self.width = 20
self.up = 10
self.down = 10
self.type = type
self.label = label
addDebug(self)
def format(self, x: float, y: float, width: float) -> Start:
path = Path(x, y - 10)
if self.type == "complex":
path.down(20).m(0, -10).right(self.width).addTo(self)
else:
path.down(20).m(10, -20).down(20).m(-10, -10).right(self.width).addTo(self)
if self.label:
DiagramItem(
"text",
attrs={"x": x, "y": y - 15, "style": "text-anchor:start"},
text=self.label,
).addTo(self)
return self
def __repr__(self) -> str:
return f"Start(type={repr(self.type)}, label={repr(self.label)})"
class End(DiagramItem):
def __init__(self, type: str = "simple"):
DiagramItem.__init__(self, "path")
self.width = 20
self.up = 10
self.down = 10
self.type = type
addDebug(self)
def format(self, x: float, y: float, width: float) -> End:
if self.type == "simple":
self.attrs["d"] = "M {0} {1} h 20 m -10 -10 v 20 m 10 -20 v 20".format(x, y)
elif self.type == "complex":
self.attrs["d"] = "M {0} {1} h 20 m 0 -10 v 20".format(x, y)
return self
def __repr__(self) -> str:
return f"End(type={repr(self.type)})"
class Terminal(DiagramItem):
def __init__(
self, text: str, href: Opt[str] = None, title: Opt[str] = None, cls: str = ""
):
DiagramItem.__init__(self, "g", {"class": " ".join(["terminal", cls])})
self.text = text
self.href = href
self.title = title
self.cls = cls
self.width = len(text) * CHAR_WIDTH + 20
self.up = 11
self.down = 11
self.needsSpace = True
addDebug(self)
def __repr__(self) -> str:
return f"Terminal({repr(self.text)}, href={repr(self.href)}, title={repr(self.title)}, cls={repr(self.cls)})"
def format(self, x: float, y: float, width: float) -> Terminal:
leftGap, rightGap = determineGaps(width, self.width)
# Hook up the two sides if self is narrower than its stated width.
Path(x, y).h(leftGap).addTo(self)
Path(x + leftGap + self.width, y).h(rightGap).addTo(self)
DiagramItem(
"rect",
{
"x": x + leftGap,
"y": y - 11,
"width": self.width,
"height": self.up + self.down,
"rx": 10,
"ry": 10,
},
).addTo(self)
text = DiagramItem(
"text", {"x": x + leftGap + self.width / 2, "y": y + 4}, self.text
)
if self.href is not None:
a = DiagramItem("a", {"xlink:href": self.href}, text).addTo(self)
text.addTo(a)
else:
text.addTo(self)
if self.title is not None:
DiagramItem("title", {}, self.title).addTo(self)
return self
class NonTerminal(DiagramItem):
def __init__(
self, text: str, href: Opt[str] = None, title: Opt[str] = None, cls: str = ""
):
DiagramItem.__init__(self, "g", {"class": " ".join(["non-terminal", cls])})
self.text = text
self.href = href
self.title = title
self.cls = cls
self.width = len(text) * CHAR_WIDTH + 20
self.up = 11
self.down = 11
self.needsSpace = True
addDebug(self)
def __repr__(self) -> str:
return f"NonTerminal({repr(self.text)}, href={repr(self.href)}, title={repr(self.title)}, cls={repr(self.cls)})"
def format(self, x: float, y: float, width: float) -> NonTerminal:
leftGap, rightGap = determineGaps(width, self.width)
# Hook up the two sides if self is narrower than its stated width.
Path(x, y).h(leftGap).addTo(self)
Path(x + leftGap + self.width, y).h(rightGap).addTo(self)
DiagramItem(
"rect",
{
"x": x + leftGap,
"y": y - 11,
"width": self.width,
"height": self.up + self.down,
},
).addTo(self)
text = DiagramItem(
"text", {"x": x + leftGap + self.width / 2, "y": y + 4}, self.text
)
if self.href is not None:
a = DiagramItem("a", {"xlink:href": self.href}, text).addTo(self)
text.addTo(a)
else:
text.addTo(self)
if self.title is not None:
DiagramItem("title", {}, self.title).addTo(self)
return self
class Comment(DiagramItem):
def __init__(
self, text: str, href: Opt[str] = None, title: Opt[str] = None, cls: str = ""
):
DiagramItem.__init__(self, "g", {"class": " ".join(["non-terminal", cls])})
self.text = text
self.href = href
self.title = title
self.cls = cls
self.width = len(text) * COMMENT_CHAR_WIDTH + 10
self.up = 8
self.down = 8
self.needsSpace = True
addDebug(self)
def __repr__(self) -> str:
return f"Comment({repr(self.text)}, href={repr(self.href)}, title={repr(self.title)}, cls={repr(self.cls)})"
def format(self, x: float, y: float, width: float) -> Comment:
leftGap, rightGap = determineGaps(width, self.width)
# Hook up the two sides if self is narrower than its stated width.
Path(x, y).h(leftGap).addTo(self)
Path(x + leftGap + self.width, y).h(rightGap).addTo(self)
text = DiagramItem(
"text",
{"x": x + leftGap + self.width / 2, "y": y + 5, "class": "comment"},
self.text,
)
if self.href is not None:
a = DiagramItem("a", {"xlink:href": self.href}, text).addTo(self)
text.addTo(a)
else:
text.addTo(self)
if self.title is not None:
DiagramItem("title", {}, self.title).addTo(self)
return self
class Skip(DiagramItem):
def __init__(self) -> None:
DiagramItem.__init__(self, "g")
self.width = 0
self.up = 0
self.down = 0
addDebug(self)
def format(self, x: float, y: float, width: float) -> Skip:
Path(x, y).right(width).addTo(self)
return self
def __repr__(self) -> str:
return "Skip()"
if __name__ == "__main__":
def add(name: str, diagram: DiagramItem) -> None:
sys.stdout.write(f"<h1>{escapeHtml(name)}</h1>\n")
diagram.writeSvg(sys.stdout.write)
sys.stdout.write("\n")
sys.stdout.write("<!doctype html><title>Test")
with open("test.py", "r", encoding="utf-8") as fh:
exec(fh.read()) # pylint: disable=exec-used
sys.stdout.write(
"""
"""
)
sys.stdout.write("