Add glacier command for adding ICE snippets easily

parser/src/command.rs

@@ -3,6 +3,7 @@ use crate::error::Error;
 use crate::token::{Token, Tokenizer};
 
 pub mod assign;
+pub mod glacier;
 pub mod nominate;
 pub mod ping;
 pub mod relabel;
@@ -17,6 +18,7 @@ pub enum Command<'a> {
     Assign(Result<assign::AssignCommand, Error<'a>>),
     Ping(Result<ping::PingCommand, Error<'a>>),
     Nominate(Result<nominate::NominateCommand, Error<'a>>),
+    Glacier(Result<glacier::GlacierCommand, Error<'a>>),
     None,
 }
 
@@ -95,6 +97,11 @@ impl<'a> Input<'a> {
             Command::Nominate,
             &original_tokenizer,
         ));
+        success.extend(parse_single_command(
+            glacier::GlacierCommand::parse,
+            Command::Glacier,
+            &original_tokenizer,
+        ));
 
         if success.len() > 1 {
             panic!(
@@ -133,6 +140,7 @@ impl<'a> Command<'a> {
             Command::Assign(r) => r.is_ok(),
             Command::Ping(r) => r.is_ok(),
             Command::Nominate(r) => r.is_ok(),
+            Command::Glacier(r) => r.is_ok(),
             Command::None => true,
         }
     }

parser/src/command/glacier.rs

@@ -0,0 +1,99 @@
+//! The glacier command parser.
+//!
+//! The grammar is as follows:
+//!
+//! ```text
+//! Command:
+//!   - `@bot glacier add <code-source>?`
+//!   - `@bot glacier remove`
+//!
+//! <code-source>:
+//!   - "https://play.rust-lang.org/.*"
+//! ```
+
+use std::fmt;
+
+use crate::error::Error;
+use crate::token::{Token, Tokenizer};
+
+#[derive(Debug, PartialEq)]
+pub enum GlacierCommand {
+    Remove,
+    Add(CodeSource),
+}
+
+#[derive(Debug, PartialEq)]
+pub enum CodeSource {
+    Post,
+    Url(String),
+}
+
+#[derive(Debug)]
+pub enum ParseError {
+    UnknownSubCommand,
+}
+
+impl std::error::Error for ParseError {}
+
+impl fmt::Display for ParseError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Self::UnknownSubCommand => write!(f, "unknown command"),
+        }
+    }
+}
+
+impl GlacierCommand {
+    pub fn parse<'a>(input: &mut Tokenizer<'a>) -> Result<Option<GlacierCommand>, Error<'a>> {
+        let mut toks = input.clone();
+        if let Some(Token::Word("glacier")) = toks.next_token()? {
+            if let Some(Token::Word("add")) = toks.peek_token()? {
+                toks.next_token()?;
+                Ok(Some(Self::Add(
+                    if let Some(Token::Quote(url)) = toks.next_token()? {
+                        CodeSource::Url(url.into())
+                    } else {
+                        CodeSource::Post
+                    },
+                )))
+            } else if let Some(Token::Word("remove")) = toks.peek_token()? {
+                Ok(Some(Self::Remove))
+            } else {
+                Err(toks.error(ParseError::UnknownSubCommand))
+            }
+        } else {
+            Ok(None)
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    fn parse<'a>(input: &'a str) -> Result<Option<GlacierCommand>, Error<'a>> {
+        let mut toks = Tokenizer::new(input);
+        Ok(GlacierCommand::parse(&mut toks)?)
+    }
+
+    #[test]
+    fn test_remove() {
+        assert_eq!(parse("glacier remove"), Ok(Some(GlacierCommand::Remove)));
+    }
+
+    #[test]
+    fn test_add_post() {
+        assert_eq!(
+            parse("glacier add"),
+            Ok(Some(GlacierCommand::Add(CodeSource::Post)))
+        );
+    }
+
+    #[test]
+    fn test_add_url() {
+        assert_eq!(
+            parse(r#"glacier add "https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=a85913678bee64a3262db9a4a59463c2""#),
+            Ok(Some(GlacierCommand::Add(CodeSource::Url("https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=a85913678bee64a3262db9a4a59463c2".into()))))
+        );
+    }
+}