1 files changed, 116 insertions, 0 deletions

diff --git a/src/utils.rs b/src/utils.rs
new file mode 100644
index 0000000..8928cfb
--- /dev/null
+++ b/src/utils.rs
@@ -0,0 +1,116 @@
+use std::path::PathBuf;
+
+pub fn pandoc_stringify(inlines: &[pandoc_ast::Inline]) -> String {
+    fn pandoc_stringify_(result: &mut String, inlines: &[pandoc_ast::Inline]) {
+        for inline in inlines {
+            match inline {
+                pandoc_ast::Inline::Str(s)
+                | pandoc_ast::Inline::Code(_, s)
+                | pandoc_ast::Inline::Math(_, s) => result.push_str(s),
+                pandoc_ast::Inline::Emph(inner)
+                | pandoc_ast::Inline::Underline(inner)
+                | pandoc_ast::Inline::Strong(inner)
+                | pandoc_ast::Inline::Strikeout(inner)
+                | pandoc_ast::Inline::Superscript(inner)
+                | pandoc_ast::Inline::Subscript(inner)
+                | pandoc_ast::Inline::SmallCaps(inner)
+                | pandoc_ast::Inline::Quoted(_, inner)
+                | pandoc_ast::Inline::Cite(_, inner)
+                | pandoc_ast::Inline::Link(_, inner, _)
+                | pandoc_ast::Inline::Image(_, inner, _)
+                | pandoc_ast::Inline::Span(_, inner) => pandoc_stringify_(result, inner),
+                pandoc_ast::Inline::Space => result.push(' '),
+                pandoc_ast::Inline::SoftBreak => todo!(),
+                pandoc_ast::Inline::LineBreak => todo!(),
+                pandoc_ast::Inline::RawInline(_, _) => todo!(),
+                pandoc_ast::Inline::Note(_) => todo!(),
+            }
+        }
+    }
+
+    let mut result = String::new();
+    pandoc_stringify_(&mut result, inlines);
+    result
+}
+
+/// Follows the algorithm specified in the Pandoc manual[1]
+///
+/// [1]: <https://pandoc.org/MANUAL.html#extension-auto_identifiers>
+#[derive(Debug)]
+pub struct AutoIdentifier(pub String);
+
+impl std::ops::Deref for AutoIdentifier {
+    type Target = String;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl From<AutoIdentifier> for String {
+    fn from(id: AutoIdentifier) -> Self {
+        id.0
+    }
+}
+
+impl From<&[pandoc_ast::Inline]> for AutoIdentifier {
+    fn from(inlines: &[pandoc_ast::Inline]) -> Self {
+        let text = pandoc_stringify(inlines);
+        AutoIdentifier::from(text.as_str())
+    }
+}
+
+impl From<&str> for AutoIdentifier {
+    fn from(text: &str) -> Self {
+        let id = text
+            .chars()
+            .skip_while(|ch| !ch.is_alphabetic())
+            .filter_map(|ch| {
+                if !ch.is_ascii_alphanumeric()
+                    && !ch.is_whitespace()
+                    && ch != '_'
+                    && ch != '-'
+                    && ch != '.'
+                {
+                    return None;
+                }
+
+                if ch.is_whitespace() {
+                    return Some('-');
+                }
+
+                Some(ch.to_ascii_lowercase())
+            })
+            .collect();
+
+        AutoIdentifier(id)
+    }
+}
+
+pub trait PandocOutputExt {
+    fn buffer(self) -> String;
+    fn file(self) -> PathBuf;
+}
+
+impl PandocOutputExt for pandoc::PandocOutput {
+    fn buffer(self) -> String {
+        match self {
+            pandoc::PandocOutput::ToBuffer(buffer) => buffer,
+            pandoc::PandocOutput::ToBufferRaw(_) => {
+                panic!("Expected text pandoc output, found binary format")
+            }
+            pandoc::PandocOutput::ToFile(_) => {
+                panic!("Expected buffered pandoc output, found file")
+            }
+        }
+    }
+
+    fn file(self) -> PathBuf {
+        match self {
+            pandoc::PandocOutput::ToFile(file) => file,
+            _ => panic!("Expected file pandoc output, found buffer"),
+        }
+    }
+}
+
+pub type PandocMeta = pandoc_ast::Map<String, pandoc_ast::MetaValue>;