link-directive-parser.rs

const INPUT: &str = r#"    o  Relation Name: alternate
   o  Description: Designates a substitute for the link's context.
   o  Reference: [W3C.REC-html401-19991224]

   o  Relation Name: appendix
   o  Description: Refers to an appendix.
   o  Reference: [W3C.REC-html401-19991224]

   o  Relation Name: bookmark
   o  Description: Refers to a bookmark or entry point.
   o  Reference: [W3C.REC-html401-19991224]

   o  Relation Name: chapter
   o  Description: Refers to a chapter in a collection of resources.
   o  Reference: [W3C.REC-html401-19991224]

   o  Relation Name: contents
   o  Description: Refers to a table of contents.
   o  Reference: [W3C.REC-html401-19991224]

   o  Relation Name: copyright
   o  Description: Refers to a copyright statement that applies to the
      link's context.
   o  Reference: [W3C.REC-html401-19991224]

   o  Relation Name: current
   o  Description: Refers to a resource containing the most recent
      item(s) in a collection of resources.
   o  Reference: [RFC5005]

   o  Relation Name: describedby
   o  Description: Refers to a resource providing information about the
      link's context.
   o  Documentation: <http://www.w3.org/TR/powder-dr/#assoc-linking>

   o  Relation Name: edit
   o  Description: Refers to a resource that can be used to edit the
      link's context.
   o  Reference: [RFC5023]

   o  Relation Name: edit-media
   o  Description: Refers to a resource that can be used to edit media
      associated with the link's context.
   o  Reference: [RFC5023]

   o  Relation Name: enclosure
   o  Description: Identifies a related resource that is potentially
      large and might require special handling.
   o  Reference: [RFC4287]

   o  Relation Name: first
   o  Description: An IRI that refers to the furthest preceding resource
      in a series of resources.
   o  Reference: [RFC5988]
   o  Notes: this relation type registration did not indicate a
      reference.  Originally requested by Mark Nottingham in December
      2004.

   o  Relation Name: glossary
   o  Description: Refers to a glossary of terms.
   o  Reference: [W3C.REC-html401-19991224]

   o  Relation Name: help
   o  Description: Refers to a resource offering help (more information,
      links to other sources information, etc.)
   o  Reference: [W3C.REC-html401-19991224]

   o  Relation Name: hub
   o  Description: Refers to a hub that enables registration for
      notification of updates to the context.
   o  Reference: <http://pubsubhubbub.googlecode.com/> <http://
      pubsubhubbub.googlecode.com/svn/trunk/pubsubhubbub-core-0.3.html>
   o  Notes: this relation type was requested by Brett Slatkin.

   o  Relation Name: index
   o  Description: Refers to an index.
   o  Reference: [W3C.REC-html401-19991224]

   o  Relation Name: last
   o  Description: An IRI that refers to the furthest following resource
      in a series of resources.
   o  Reference: [RFC5988]
   o  Notes: this relation type registration did not indicate a
      reference.  Originally requested by Mark Nottingham in December
      2004.

   o  Relation Name: latest-version
   o  Description: Points to a resource containing the latest (e.g.,
      current) version of the context.
   o  Reference: [RFC5829]

   o  Relation Name: license
   o  Description: Refers to a license associated with the link's
      context.
   o  Reference: [RFC4946]

   o  Relation Name: next
   o  Description: Refers to the next resource in a ordered series of
      resources.
   o  Reference: [W3C.REC-html401-19991224]

   o  Relation Name: next-archive
   o  Description: Refers to the immediately following archive resource.
   o  Reference: [RFC5005]

   o  Relation Name: payment
   o  Description: indicates a resource where payment is accepted.
   o  Reference: [RFC5988]
   o  Notes: this relation type registration did not indicate a
      reference.  Requested by Joshua Kinberg and Robert Sayre.  It is
      meant as a general way to facilitate acts of payment, and thus
      this specification makes no assumptions on the type of payment or
      transaction protocol.  Examples may include a Web page where
      donations are accepted or where goods and services are available
      for purchase. rel="payment" is not intended to initiate an
      automated transaction.  In Atom documents, a link element with a
      rel="payment" attribute may exist at the feed/channel level and/or
      the entry/item level.  For example, a rel="payment" link at the
      feed/channel level may point to a "tip jar" URI, whereas an entry/
      item containing a book review may include a rel="payment" link
      that points to the location where the book may be purchased
      through an online retailer.

   o  Relation Name: prev
   o  Description: Refers to the previous resource in an ordered series
      of resources.  Synonym for "previous".
   o  Reference: [W3C.REC-html401-19991224]

   o  Relation Name: predecessor-version
   o  Description: Points to a resource containing the predecessor
      version in the version history.
   o  Reference: [RFC5829]

   o  Relation Name: previous
   o  Description: Refers to the previous resource in an ordered series
      of resources.  Synonym for "prev".
   o  Reference: [W3C.REC-html401-19991224]

   o  Relation Name: prev-archive
   o  Description: Refers to the immediately preceding archive resource.
   o  Reference: [RFC5005]

   o  Relation Name: related
   o  Description: Identifies a related resource.
   o  Reference: [RFC4287]

   o  Relation Name: replies
   o  Description: Identifies a resource that is a reply to the context
      of the link.
   o  Reference: [RFC4685]

   o  Relation Name: section
   o  Description: Refers to a section in a collection of resources.
   o  Reference: [W3C.REC-html401-19991224]

   o  Relation Name: self
   o  Description: Conveys an identifier for the link's context.
   o  Reference: [RFC4287]

   o  Relation Name: service
   o  Description: Indicates a URI that can be used to retrieve a
      service document.
   o  Reference: [RFC5023]
   o  Notes: When used in an Atom document, this relation type specifies
      Atom Publishing Protocol service documents by default.  Requested
      by James Snell.

   o  Relation Name: start
   o  Description: Refers to the first resource in a collection of
      resources.
   o  Reference: [W3C.REC-html401-19991224]

   o  Relation Name: stylesheet
   o  Description: Refers to an external style sheet.
   o  Reference: [W3C.REC-html401-19991224]

   o  Relation Name: subsection
   o  Description: Refers to a resource serving as a subsection in a
      collection of resources.
   o  Reference: [W3C.REC-html401-19991224]

   o  Relation Name: successor-version
   o  Description: Points to a resource containing the successor version
      in the version history.
   o  Reference: [RFC5829]

   o  Relation Name: up
   o  Description: Refers to a parent document in a hierarchy of
      documents.
   o  Reference: [RFC5988]
   o  Notes: this relation type registration did not indicate a
      reference.  Requested by Noah Slater.

   o  Relation Name: version-history
   o  Description: points to a resource containing the version history
      for the context.
   o  Reference: [RFC5829]

   o  Relation Name: via
   o  Description: Identifies a resource that is the source of the
      information in the link's context.
   o  Reference: [RFC4287]

   o  Relation Name: working-copy
   o  Description: Points to a working copy for this resource.
   o  Reference: [RFC5829]

   o  Relation Name: working-copy-of
   o  Description: Points to the versioned resource from which this
      working copy was obtained.
   o  Reference: [RFC5829]
"#;

fn main() {
    let mut names: Vec<(String, String)> = vec![];
    
    println!("#[non_exhaustive]\npub enum RelationType {{");
    for group in INPUT.split("\n\n") {
        // parse input data
        let lines: Vec<String> = group.split("   o  ").map(|l| l.trim().to_owned()).collect();
        let mut lines = lines.iter().skip(1);
        let relation_name = lines.next().unwrap().replace("Relation Name: ", "").replace("\n      ", "\n    /// ");
        let description = lines.next().unwrap().replace("Description: ", "").replace("\n      ", "\n    /// ");
        let reference = lines.next().unwrap().replace("Reference: ", "");
        
        // prep values
        let notes = lines.next().map(|notes| {
            let notes = notes.replace("Notes:", "");
            let mut out = String::new();
            notes.lines().for_each(|line| {
                out.push_str(&format!("\n    /// {}", line.trim()));
            });
            out
        });
        let mut reference = reference.replace("[", "").replace("]", "");
        if reference.starts_with("W3C") {
            reference = format!("rfc5988#ref-{}", reference);
        }
        let type_name = kebab(&relation_name);
        names.push((relation_name.into(), type_name.clone().into()));
        
        // print struct
        println!("    /// {}", description.trim());
        if let Some(notes) = notes {
            println!("    ///\n    /// # Notes\n    ///{}", notes);
        }
        println!("    ///\n    /// # References\n    ///");
        println!("    /// - [{}](https://tools.ietf.org/html/{})", reference, reference);
        println!("    {},", type_name);
        println!("");
    }
    println!("}}\n");
    
    // Print Display
    println!("impl Display for RelationType {{\n    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {{");
    println!("        match self {{");
    for (rel_name, ty_name) in &names {
        println!(r#"            Self::{} => write!(f, "{}"),"#, ty_name, rel_name);
    }
    println!("        }}");
    println!("    }}");
    println!("}}");
    
    // Print FromStr
    println!("impl FromStr for RelationType {{\n    type Err = crate::Error;\n\n    fn from_str(s: &str) -> Result<Self, Self::Err> {{");
    println!("        match s {{");
    for (rel_name, ty_name) in names {
        println!(r#"            "{}" => Ok(Self::{}),"#, rel_name, ty_name);
    }
    println!(r#"            s => bail!(400, "{{}} is not a recognized relation type" , s),"#);
    println!("        }}");
    println!("    }}");
    println!("}}");
}

fn kebab(s: &str) -> String {
    let mut out = String::new();
    for s in s.trim().split('-') {
        let mut chars = s.chars();
        let first = chars.next().unwrap().to_uppercase().to_string();
        out.push_str(first.as_str());
        chars.for_each(|c| out.push(c));
    }
    out
}