Add support for serializing mdast as markdown

Closes GH-64.
Closes GH-127.

Reviewed-by: Titus Wormer <[email protected]>

.github/workflows/main.yml

@@ -13,6 +13,8 @@ jobs:
           components: rustfmt, clippy
       - run: cargo fmt --check && cargo clippy --examples --tests --benches --all-features
       - run: cargo test --all-features
+      - run: cargo clippy -p mdast_util_to_markdown
+      - run: cargo test -p mdast_util_to_markdown
   coverage:
     runs-on: ubuntu-latest
     steps:

Cargo.toml

@@ -12,6 +12,12 @@ keywords = ["commonmark", "markdown", "parse", "render", "tokenize"]
 categories = ["compilers", "encoding", "parser-implementations", "parsing", "text-processing"]
 include = ["src/", "license"]
 
+[workspace]
+members = ["generate", "mdast_util_to_markdown"]
+
+[workspace.dependencies]
+pretty_assertions = "1"
+
 [[bench]]
 name = "bench"
 path = "benches/bench.rs"
@@ -31,14 +37,11 @@ serde = { version = "1", features = ["derive"], optional = true }
 [dev-dependencies]
 env_logger = "0.11"
 criterion = "0.5"
-pretty_assertions = "1"
+pretty_assertions = { workspace = true }
 serde_json = { version = "1" }
 swc_core = { version = "0.100", features = [
   "ecma_ast",
   "ecma_visit",
   "ecma_parser",
   "common",
 ] }
-
-[workspace]
-members = ["generate"]

mdast_util_to_markdown/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "mdast_util_to_markdown"
+version = "0.0.0"
+edition = "2018"
+license = "MIT"
+
+[dependencies]
+markdown = { path = "../" }
+regex = { version = "1" }
+
+[dev-dependencies]
+pretty_assertions = { workspace = true }

mdast_util_to_markdown/src/association.rs

@@ -0,0 +1,37 @@
+use alloc::string::String;
+use markdown::mdast::{Definition, ImageReference, LinkReference};
+
+pub trait Association {
+    fn identifier(&self) -> &String;
+    fn label(&self) -> &Option<String>;
+}
+
+impl Association for Definition {
+    fn identifier(&self) -> &String {
+        &self.identifier
+    }
+
+    fn label(&self) -> &Option<String> {
+        &self.label
+    }
+}
+
+impl Association for ImageReference {
+    fn identifier(&self) -> &String {
+        &self.identifier
+    }
+
+    fn label(&self) -> &Option<String> {
+        &self.label
+    }
+}
+
+impl Association for LinkReference {
+    fn identifier(&self) -> &String {
+        &self.identifier
+    }
+
+    fn label(&self) -> &Option<String> {
+        &self.label
+    }
+}

mdast_util_to_markdown/src/configure.rs

@@ -0,0 +1,77 @@
+pub struct Options {
+    /// Marker to use for bullets of items in unordered lists ('*', '+', or '-', default: '*').
+    pub bullet: char,
+    // Marker to use in certain cases where the primary bullet doesn’t work
+    // ('*', '+', or '-', default: '-' when bullet is '*', '*' otherwise).
+    pub bullet_other: char,
+    /// Marker to use for bullets of items in ordered lists ('.' or ')', default: '.').
+    pub bullet_ordered: char,
+    /// Marker to use for emphasis ('*' or '_', default: '*').
+    pub emphasis: char,
+    // Marker to use for fenced code ('`' or '~', default: '`').
+    pub fence: char,
+    /// Whether to use fenced code always (bool, default: true). The default is to use fenced code
+    /// if there is a language defined, if the code is empty, or if it starts or ends in blank lines.
+    pub fences: bool,
+    // How to indent the content of list items (default: 'IndentOptions::One').
+    pub list_item_indent: IndentOptions,
+    /// Marker to use for titles ('"' or "'", default: '"').
+    pub quote: char,
+    /// Marker to use for thematic breaks ('*', '-', or '_', default: '*').
+    pub rule: char,
+    // Marker to use for strong ('*' or '_', default: '*').
+    pub strong: char,
+    // Whether to increment the counter of ordered lists items (bool, default: true).
+    pub increment_list_marker: bool,
+    /// Whether to add the same number of number signs (#) at the end of an ATX heading as the
+    /// opening sequence (bool, default: false).
+    pub close_atx: bool,
+    /// Whether to always use resource links (bool, default: false). The default is to use autolinks
+    /// (<https://example.com>) when possible and resource links ([text](url)) otherwise.
+    pub resource_link: bool,
+    /// Whether to add spaces between markers in thematic breaks (bool, default: false).
+    pub rule_spaces: bool,
+    /// Whether to use setext headings when possible (bool, default: false). The default is to always
+    /// use ATX headings (# heading) instead of setext headings (heading\n=======). Setext headings
+    /// cannot be used for empty headings or headings with a rank of three or more.
+    pub setext: bool,
+    /// Whether to join definitions without a blank line (bool, default: false).
+    pub tight_definitions: bool,
+    // Number of markers to use for thematic breaks (u32, default: 3, min: 3).
+    pub rule_repetition: u32,
+}
+
+#[derive(Copy, Clone)]
+pub enum IndentOptions {
+    // Depends on the item and its parent list uses 'One' if the item and list are tight and 'Tab'
+    // otherwise.
+    Mixed,
+    // The size of the bullet plus one space.
+    One,
+    /// Tab stop.
+    Tab,
+}
+
+impl Default for Options {
+    fn default() -> Self {
+        Self {
+            bullet: '*',
+            bullet_other: '-',
+            bullet_ordered: '.',
+            emphasis: '*',
+            fence: '`',
+            fences: true,
+            increment_list_marker: true,
+            rule_repetition: 3,
+            list_item_indent: IndentOptions::One,
+            quote: '"',
+            rule: '*',
+            strong: '*',
+            close_atx: false,
+            rule_spaces: false,
+            resource_link: false,
+            setext: false,
+            tight_definitions: false,
+        }
+    }
+}