Add word-level parsing

src/syntax/content/parser/token/paragraph.rs

@@ -0,0 +1,53 @@
+use std::fmt::Display;
+use crate::syntax::content::{Parseable, parser::lexeme::Lexeme};
+
+pub struct Paragraph {
+    open: Option<bool>,
+}
+
+impl Paragraph {
+    pub fn new(open: bool) -> Paragraph {
+        Paragraph { open: Some(open) }
+    }
+}
+
+impl Parseable for Paragraph {
+    fn probe(lexeme: &Lexeme) -> bool {
+        // lexeme for paragraph is any non-whitespace, parser knows the context
+        let raw = lexeme.to_raw();
+        let trimmed = raw.trim();
+        !trimmed.is_empty() && trimmed != "\n"
+    }
+
+    fn lex(_lexeme: &Lexeme) -> Paragraph {
+        Paragraph { open: None }
+    }
+
+    fn render(&self) -> String {
+        if let Some(open) = self.open {
+            if open {
+                "<p>".to_owned()
+            } else {
+                "</p>".to_owned()
+            }
+        } else {
+            panic!(
+                "Attempt to render a paragraph tag while open state is unknown"
+            )
+        }
+    }
+}
+
+impl Display for Paragraph {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        if let Some(open) = self.open {
+            if open {
+                write!(f, "Open Paragraph")
+            } else {
+                write!(f, "Closed Paragraph")
+            }
+        } else {
+            write!(f, "Unitialized Paragraph (Unknown open state)")
+        }
+    }
+}