remove unspecified inline code tag support

src/line/code.rs

@@ -1,7 +1,90 @@
-pub mod inline;
-pub mod multiline;
-
-pub use inline::Inline;
-pub use multiline::Multiline;
+pub mod error;
+pub use error::Error;
 
 pub const TAG: &str = "```";
+pub const NEW_LINE: char = '\n';
+
+/// Multi-line [preformatted](https://geminiprotocol.net/docs/gemtext-specification.gmi#in-pre-formatted-mode) entity holder
+pub struct Code {
+    pub alt: Option<String>,
+    pub value: String,
+    pub is_completed: bool,
+}
+
+impl Code {
+    // Constructors
+
+    /// Search in line string for tag open,
+    /// return Self constructed on success or None
+    pub fn begin_from(line: &str) -> Option<Self> {
+        if line.starts_with(TAG) {
+            let alt = line.trim_start_matches(TAG).trim();
+
+            return Some(Self {
+                alt: match alt.is_empty() {
+                    true => None,
+                    false => Some(alt.to_string()),
+                },
+                value: String::new(),
+                is_completed: false,
+            });
+        }
+        None
+    }
+
+    /// Continue preformatted buffer from line string,
+    /// set `completed` as True on close tag found
+    pub fn continue_from(&mut self, line: &str) -> Result<(), Error> {
+        // Make sure buffer not completed yet
+        if self.is_completed {
+            return Err(Error::Completed);
+        }
+
+        // Append to value, trim close tag on exists
+        self.value.push_str(line.trim_end_matches(TAG));
+
+        // Line contain close tag
+        if line.ends_with(TAG) {
+            self.is_completed = true;
+        } else {
+            self.value.push(NEW_LINE);
+        }
+
+        Ok(())
+    }
+
+    // Converters
+
+    /// Convert `Self` to [Gemtext](https://geminiprotocol.net/docs/gemtext-specification.gmi) format
+    pub fn to_source(&self) -> String {
+        format!(
+            "{TAG}{}{NEW_LINE}{}{TAG}",
+            match &self.alt {
+                Some(alt) => format!(" {}", alt.trim()),
+                None => String::new(),
+            },
+            self.value
+        )
+    }
+}
+
+#[test]
+fn test() {
+    match Code::begin_from("```alt") {
+        Some(mut code) => {
+            assert!(code.continue_from("line 1").is_ok());
+            assert!(code.continue_from("line 2").is_ok());
+            assert!(code.continue_from("```").is_ok()); // complete
+
+            assert!(code.is_completed);
+            assert_eq!(code.alt, Some("alt".into()));
+            assert_eq!(code.value.len(), 12 + 2); // +NL
+
+            assert_eq!(
+                code.to_source(),
+                format!("{TAG} alt{NEW_LINE}line 1{NEW_LINE}line 2{NEW_LINE}{TAG}")
+            )
+        }
+        None => assert!(false),
+    }
+}