Add AsciiMath inline and block parsing

Cargo.lock

@@ -21,6 +21,17 @@ dependencies = [
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "asciimath-rs"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "charred 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "htmlescape 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "maplit 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "atty"
 version = "0.2.14"
@@ -75,6 +86,11 @@ name = "charred"
 version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "charred"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "chrono"
 version = "0.4.11"
@@ -299,6 +315,11 @@ dependencies = [
  "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "maplit"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "memchr"
 version = "2.3.3"
@@ -573,6 +594,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 name = "snekdown"
 version = "0.18.3"
 dependencies = [
+ "asciimath-rs 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "charred 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "chrono 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "colored 1.9.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -789,6 +811,7 @@ dependencies = [
 "checksum adler32 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "5d2e7343e7fc9de883d1b0341e0b13970f764c14101234857d2ddafa1cb1cac2"
 "checksum aho-corasick 0.7.10 (registry+https://github.com/rust-lang/crates.io-index)" = "8716408b8bc624ed7f65d223ddb9ac2d044c0547b6fa4b0d554f3a9540496ada"
 "checksum ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
+"checksum asciimath-rs 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "60e268057257d5bb6a296d0412445b54f7e36bb90d7bc0071f31310a4231c8ec"
 "checksum atty 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)" = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
 "checksum autocfg 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f8aac770f1885fd7e387acedd76065302551364496e46b3dd00860b2f8359b9d"
 "checksum base64 0.12.1 (registry+https://github.com/rust-lang/crates.io-index)" = "53d1ccbaf7d9ec9537465a97bf19edc1a4e158ecb49fc16178202238c569cc42"
@@ -798,6 +821,7 @@ dependencies = [
 "checksum cc 1.0.54 (registry+https://github.com/rust-lang/crates.io-index)" = "7bbb73db36c1246e9034e307d0fba23f9a2e251faa47ade70c1bd252220c8311"
 "checksum cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 "checksum charred 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "8cf73c7fbbaf59d5643f99c6a4413eba1b914a7489c39b730ec7d8d72e7bb061"
+"checksum charred 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "81443b6f18b18560f94a0e14d529a1db379581473217b1b2a40ecae0c96a5d0e"
 "checksum chrono 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)" = "80094f509cf8b5ae86a4966a39b3ff66cd7e2a3e594accec3743ff3fabeab5b2"
 "checksum clap 2.33.1 (registry+https://github.com/rust-lang/crates.io-index)" = "bdfa80d47f954d53a35a64987ca1422f495b8d6483c0fe9f7117b36c2a792129"
 "checksum colored 1.9.3 (registry+https://github.com/rust-lang/crates.io-index)" = "f4ffc801dacf156c5854b9df4f425a626539c3a6ef7893cc0c5084a23f0b6c59"
@@ -826,6 +850,7 @@ dependencies = [
 "checksum line-wrap 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "f30344350a2a51da54c1d53be93fade8a237e545dbcc4bdbe635413f2117cab9"
 "checksum linked-hash-map 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)" = "8dd5a6d5999d9907cda8ed67bbd137d3af8085216c2ac62de5be860bd41f304a"
 "checksum log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)" = "14b6052be84e6b71ab17edffc2eeabf5c2c3ae1fdb464aae35ac50c67a44e1f7"
+"checksum maplit 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "3e2e65a1a2e43cfcb47a895c4c8b10d1f4a61097f9f254f183aee60cad9c651d"
 "checksum memchr 2.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3728d817d99e5ac407411fa471ff9800a778d88a24685968b36824eaf4bee400"
 "checksum minify 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2ef7c582bd7587da887914eaf294897e82f2f5c98b741f137f2a918cd26a885b"
 "checksum miniz_oxide 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "aa679ff6578b1cddee93d7e82e263b94a575e0bfced07284eb0c037c1d2416a5"

Cargo.toml

@@ -32,3 +32,4 @@ notify = "4.0.12"
 toml = "0.5.6"
 serde ="1.0.111"
 serde_derive = "1.0.111"
+asciimath-rs = "0.4.0"

README.md

@@ -184,6 +184,22 @@ There is a book about snekdown[^book] and a github repo[^github].
 
 Bibliography entries are only shown when used in the document.
 
+
+## Math
+
+Snekdown allows the embedding of [AsciiMath](http://asciimath.org/):
+
+```
+inline math $$ a^2 + b^2 = c^2 $$
+
+Block Math
+$$$
+A = [[1, 2],[3,4]]
+$$$
+```
+
+Currently math only get's rendered into MathML which is only supported by Safari and Firefox.
+
 ## Roadmap
 
 The end goal is to have a markup language with features similar to LaTeX.
@@ -194,7 +210,7 @@ The end goal is to have a markup language with features similar to LaTeX.
 - [x] Watching and rendering on change
 - [ ] Metadata files
 - [x] Bibliography
-- [ ] Math
+- [x] Math
 - [ ] Text sizes
 - [ ] Title pages
 - [ ] Glossary

src/elements/mod.rs

@@ -4,6 +4,7 @@ use crate::references::bibliography::{BibEntry, BibReference, Bibliography};
 use crate::references::configuration::Configuration;
 use crate::references::placeholders::ProcessPlaceholders;
 use crate::references::templates::{Template, TemplateVariable};
+use asciimath_rs::elements::special::Expression;
 use std::collections::HashMap;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, RwLock};
@@ -40,6 +41,7 @@ pub enum Block {
     List(List),
     Table(Table),
     CodeBlock(CodeBlock),
+    MathBlock(MathBlock),
     Quote(Quote),
     Import(Import),
     Placeholder(Arc<RwLock<Placeholder>>),
@@ -164,6 +166,7 @@ pub enum Inline {
     Checkbox(Checkbox),
     Emoji(Emoji),
     Colored(Colored),
+    Math(Math),
     BibReference(Arc<RwLock<BibReference>>),
     TemplateVar(Arc<RwLock<TemplateVariable>>),
 }
@@ -250,6 +253,16 @@ pub struct Colored {
     pub(crate) color: String,
 }
 
+#[derive(Clone, Debug)]
+pub struct Math {
+    pub(crate) expression: Expression,
+}
+
+#[derive(Clone, Debug)]
+pub struct MathBlock {
+    pub(crate) expression: Expression,
+}
+
 // implementations
 
 impl Document {

src/elements/tokens.rs

@@ -32,6 +32,7 @@ pub(crate) const R_BRACE: char = '{';
 pub(crate) const L_BRACE: char = '}';
 pub(crate) const PERCENT: char = '%';
 pub(crate) const COMMA: char = ',';
+pub(crate) const MATH: char = '$';
 
 // aliases
 
@@ -71,13 +72,14 @@ pub(crate) const STRIKED: char = TILDE;
 pub(crate) const UNDERLINED: char = UNDERSCR;
 pub(crate) const SUPER: char = UP;
 pub(crate) const EMOJI: char = COLON;
+pub(crate) const MATH_INLINE: &'static [char] = &[MATH, MATH];
 pub(crate) const BOLD: [char; 2] = [ASTERISK, ASTERISK];
 
 // groups
 
 pub(crate) const QUOTES: [char; 2] = [SINGLE_QUOTE, DOUBLE_QUOTE];
 
-pub(crate) const BLOCK_SPECIAL_CHARS: [&[char]; 9] = [
+pub(crate) const BLOCK_SPECIAL_CHARS: &'static [&[char]] = &[
     &[HASH],
     &[HASH, META_OPEN],
     &[MINUS, SPACE],
@@ -87,9 +89,10 @@ pub(crate) const BLOCK_SPECIAL_CHARS: [&[char]; 9] = [
     &[META_OPEN],
     &[IMPORT_START, IMPORT_OPEN],
     &SQ_CENTERED_START,
+    &SQ_MATH,
 ];
 
-pub(crate) const INLINE_SPECIAL_CHARS: [char; 11] = [
+pub(crate) const INLINE_SPECIAL_CHARS: &'static [char] = &[
     BACKTICK,
     TILDE,
     UNDERSCR,
@@ -101,6 +104,7 @@ pub(crate) const INLINE_SPECIAL_CHARS: [char; 11] = [
     SUPER,
     EMOJI,
     COLOR_START,
+    MATH,
 ];
 
 pub(crate) const LIST_SPECIAL_CHARS: [char; 14] = [
@@ -119,3 +123,4 @@ pub(crate) const SQ_PHOLDER_STOP: [char; 2] = [PHOLDER_CLOSE, PHOLDER_CLOSE];
 pub(crate) const SQ_CENTERED_START: [char; 2] = [PIPE, PIPE];
 pub(crate) const SQ_COLOR_START: [char; 2] = [COLOR_START, COLOR_OPEN];
 pub(crate) const SQ_BIBREF_START: [char; 2] = [BIBREF_OPEN, BIBREF_REF];
+pub(crate) const SQ_MATH: &'static [char] = &[MATH, MATH, MATH];

src/format/html.rs

@@ -3,6 +3,7 @@ use crate::format::PlaceholderTemplate;
 use crate::references::bibliography::{BibEntry, BibReference};
 use crate::references::configuration::Value;
 use crate::references::templates::{Template, TemplateVariable};
+use asciimath_rs::format::mathml::ToMathML;
 use htmlescape::{encode_attribute, encode_minimal};
 use minify::html::minify;
 use std::cell::RefCell;
@@ -64,6 +65,7 @@ impl ToHtml for Inline {
             Inline::Colored(colored) => colored.to_html(),
             Inline::BibReference(bibref) => bibref.read().unwrap().to_html(),
             Inline::TemplateVar(var) => var.read().unwrap().to_html(),
+            Inline::Math(m) => m.to_html(),
         }
     }
 }
@@ -79,6 +81,7 @@ impl ToHtml for Block {
             Block::Section(section) => section.to_html(),
             Block::Import(import) => import.to_html(),
             Block::Placeholder(placeholder) => placeholder.read().unwrap().to_html(),
+            Block::MathBlock(m) => m.to_html(),
         }
     }
 }
@@ -122,6 +125,24 @@ impl ToHtml for Document {
     }
 }
 
+impl ToHtml for Math {
+    fn to_html(&self) -> String {
+        format!(
+            "<math xmlns='http://www.w3.org/1998/Math/MathML'>{}</math>",
+            self.expression.to_mathml()
+        )
+    }
+}
+
+impl ToHtml for MathBlock {
+    fn to_html(&self) -> String {
+        format!(
+            "<math xmlns='http://www.w3.org/1998/Math/MathML' display='block'>{}</math>",
+            self.expression.to_mathml()
+        )
+    }
+}
+
 impl ToHtml for Import {
     fn to_html(&self) -> String {
         let anchor = self.anchor.read().unwrap();

src/parser/block.rs

@@ -1,6 +1,8 @@
 use super::ParseResult;
 use crate::elements::tokens::*;
-use crate::elements::{Block, CodeBlock, Import, List, ListItem, Paragraph, Quote, Section, Table};
+use crate::elements::{
+    Block, CodeBlock, Import, List, ListItem, MathBlock, Paragraph, Quote, Section, Table,
+};
 use crate::parser::inline::ParseInline;
 use crate::parser::line::ParseLine;
 use crate::Parser;
@@ -9,6 +11,7 @@ pub(crate) trait ParseBlock {
     fn parse_block(&mut self) -> ParseResult<Block>;
     fn parse_section(&mut self) -> ParseResult<Section>;
     fn parse_code_block(&mut self) -> ParseResult<CodeBlock>;
+    fn parse_math_block(&mut self) -> ParseResult<MathBlock>;
     fn parse_quote(&mut self) -> ParseResult<Quote>;
     fn parse_paragraph(&mut self) -> ParseResult<Paragraph>;
     fn parse_list(&mut self) -> ParseResult<List>;
@@ -36,6 +39,8 @@ impl ParseBlock for Parser {
             Block::Table(table)
         } else if let Ok(code_block) = self.parse_code_block() {
             Block::CodeBlock(code_block)
+        } else if let Ok(math_block) = self.parse_math_block() {
+            Block::MathBlock(math_block)
         } else if let Ok(quote) = self.parse_quote() {
             Block::Quote(quote)
         } else if let Ok(import) = self.parse_import() {
@@ -120,6 +125,21 @@ impl ParseBlock for Parser {
         })
     }
 
+    /// parses a math block
+    fn parse_math_block(&mut self) -> ParseResult<MathBlock> {
+        let start_index = self.ctm.get_index();
+        self.ctm.seek_whitespace();
+        self.ctm.assert_sequence(SQ_MATH, Some(start_index))?;
+        self.ctm.seek_one()?;
+        let text = self.ctm.get_string_until_sequence(&[SQ_MATH], &[])?;
+        for _ in 0..1 {
+            self.ctm.seek_one()?;
+        }
+        Ok(MathBlock {
+            expression: asciimath_rs::parse(text),
+        })
+    }
+
     /// parses a quote
     fn parse_quote(&mut self) -> ParseResult<Quote> {
         let start_index = self.ctm.get_index();

src/parser/inline.rs

@@ -18,6 +18,7 @@ pub(crate) trait ParseInline {
     fn parse_bold(&mut self) -> ParseResult<BoldText>;
     fn parse_italic(&mut self) -> ParseResult<ItalicText>;
     fn parse_striked(&mut self) -> ParseResult<StrikedText>;
+    fn parse_math(&mut self) -> ParseResult<Math>;
     fn parse_monospace(&mut self) -> ParseResult<MonospaceText>;
     fn parse_underlined(&mut self) -> ParseResult<UnderlinedText>;
     fn parse_superscript(&mut self) -> ParseResult<SuperscriptText>;
@@ -84,6 +85,8 @@ impl ParseInline for Parser {
             Ok(Inline::Colored(colored))
         } else if let Ok(bibref) = self.parse_bibref() {
             Ok(Inline::BibReference(bibref))
+        } else if let Ok(math) = self.parse_math() {
+            Ok(Inline::Math(math))
         } else {
             Ok(Inline::Plain(self.parse_plain()?))
         }
@@ -195,6 +198,20 @@ impl ParseInline for Parser {
         })
     }
 
+    fn parse_math(&mut self) -> ParseResult<Math> {
+        let start_index = self.ctm.get_index();
+        self.ctm.assert_sequence(&MATH_INLINE, Some(start_index))?;
+        self.ctm.seek_one()?;
+        let content = self
+            .ctm
+            .get_string_until_sequence(&[MATH_INLINE, &[LB]], &[])?;
+        self.ctm.seek_one()?;
+
+        Ok(Math {
+            expression: asciimath_rs::parse(content),
+        })
+    }
+
     /// parses monospace text (inline-code) that isn't allowed to contain special characters
     fn parse_monospace(&mut self) -> ParseResult<MonospaceText> {
         let start_index = self.ctm.get_index();