16 releases

new 0.2.8	Nov 23, 2024
0.2.4	Jul 12, 2024
0.1.8	Apr 6, 2021
0.1.7	Mar 21, 2021
0.1.4	Nov 5, 2020

#269 in Web programming

190 downloads per month

Custom license

110KB
2.5K SLoC

SEAM

Symbolic Expressions As Markup.

Why

Because all markup is terrible, especially XML/SGML and derivatives.

But mainly, for easier static markup code generation, such as with macros, code includes and such.

Try it out

This may be used as a library, such as from within a server, generating HTML (or any other supported markup) before it is served to the client. Personally, I am currently just using the seam binary to statically generate some personal and project websites.

Read the USAGE.md file for code examples and documentation.

Current Formats

XML (--xml; including: SVG, MathML)
HTML (--html; SGML)
CSS (--css)
SExp (--sexp; S-expression, basically a macro expansion utility)
Plain Text (--text; renders escaped strings to text)

Installation

You may clone the repo, then build and install

git clone git://git.knutsen.co/seam
cd seam
cargo build --release
cargo install --path .

Or install it from crates.io

cargo install seam

Either way, you'll need the Rust (nightly) compiler and along with it, comes cargo.

Using The Binary

You may use it by doing

seam test.sex --html > test.html

test.sex contains your symbolic-expressions, which is used to generate HTML, saved in test.html.

Likewise, you may read from STDIN

seam --html < example.sex > example.html
# Which is the same as
cat example.sex | seam --html > example.html

You may also very well use here-strings and here-docs, if your shell supports it.

seam --html <<< "(p Hello World)"
#stdout:
#   <!DOCTYPE html>
#   <html>
#   <head></head>
#   <body>
#   <p>Hello World</p>
#   </body>
#   </html>

seam --html --nodocument <<< "(p Hello World)"
#stdout:
#   <p>Hello World</p>

seam --xml <<< '(para Today is a day in (%date "%B, year %Y").)'
#stdout:
#   <?xml version="1.0" encoding="UTF-8" ?>
#   <para>Today is a day in November, year 2020.</para>

seam --sexp <<< '(hello (%define subject world) %subject)'
#stdout:
#   (hello world)

Checklist

First argument (of body) in a macro invocation should have its whitespace stripped.
(%os/env ENV_VAR) environment variable macro.
(%to-string ...), (%join ...), (%map ...), (%filter ...) macros.
Escape evaluating macros with \%.
(%format "{}") macro with Rust's format syntax. e.g. (%format "Hello {}, age {age:0>2}" "Sam" :age 9)
Add (%raw ...) macro which takes a string and leaves it unchanged in the final output. Can also take any othe source code, for which it just embeds the expanded code (plain-text formatter).
(%formatter/html ...) etc. which call the respective available formatters.
Implement lexical scope by letting macros store a copy of the scope they were defined in (or a reference?).
(%embed "/path") macro, like %include, but just returns the file contents as a string.
Variadic arguments via &rest syntax.
Delayed evaluation of macros by %(...) syntax. [ ] For example %(f x y) is the same as (%f x y), so you can have (%define uneval f x) and then write %(%uneval y).
%list macro which expands from (p (%list a b c)) to (p a b c). Defined as such:
```
(%define (list &rest) rest)
```
%for-loop macro, iterating over %lists.
%glob which returns a list of files/directories matching a glob.
%markdown renders Markdown given to it as html.
%html, %xml, %css, etc. macros which goes into the specific rendering mode.
Add variadic and keyword macro arguments.
Caching or checking time-stamps as to not regenerate unmodified source files.
HTML object style="..." object should handle s-expressions well, (e.g. (p :style (:color red :border none) Hello World))
Add more supported formats (JSON, JS, TOML, &c.).

Maybe: a whole JavaScript front-end, e.g.

(let x 2)
(let (y 1) (z 1))
(const f (=> (a b) (+ a b))
((. console log) (== (f y z) x))

Add more helpful/generic macros (e.g. (%include ...), which already exists).
Allow for arbitrary embedding of code, that can be run by a LISP interpreter (or any other langauge), for example. (e.g. (%chez (+ 1 2)) executes (+ 1 2) with Chez-Scheme LISP, and places the result in the source (i.e. 3).

Dependencies

~2–12MB
~80K SLoC