1 files changed, 80 insertions, 0 deletions

diff --git a/src/lex.rs b/src/lex.rs
new file mode 100644
index 0000000..0f9a535
--- /dev/null
+++ b/src/lex.rs
@@ -0,0 +1,80 @@
+use crate::utils::FromStaticStr;
+
+pub enum Stanza {
+    Entry(&'static str),
+    Defn(&'static str),
+    Note(&'static str),
+    Synonym(&'static str),
+    Bullet(&'static str),
+    SubBullet(&'static str),
+}
+
+impl Stanza {
+    fn is_entry(s: &str) -> bool {
+        s.chars().all(|c| c.is_uppercase() || c.is_ascii_whitespace() || "-;'.".contains(c))
+    }
+
+    fn is_defn(s: &str) -> bool {
+        s.starts_with("Defn")
+    }
+
+    fn is_note(s: &str) -> bool {
+        s.starts_with("Note")
+    }
+
+    fn is_synonym(s: &str) -> bool {
+        s.starts_with("Syn")
+    }
+
+    fn is_bullet(s: &str) -> bool {
+        s.find('.').map(|idx| s[..idx].chars().all(char::is_numeric)).unwrap_or_default()
+    }
+
+    fn is_sub_bullet(s: &str) -> bool {
+        let mut chars = s.chars();
+        chars.next().map(|c| c == '(').unwrap_or_default()
+            && chars.next().map(char::is_alphabetic).unwrap_or_default()
+            && chars.next().map(|c| c == ')').unwrap_or_default()
+    }
+}
+
+pub struct StanzaLexError {
+    pub data: String,
+}
+
+impl FromStaticStr for Stanza {
+    type Err = StanzaLexError;
+    fn from_str(s: &'static str) -> Result<Self, Self::Err> {
+        let mut lines = s.split("\n");
+        if let Some(first_line) = lines.next() {
+            if !first_line.is_empty() {
+                if Stanza::is_entry(first_line) {
+                    Ok(Self::Entry(s))
+                } else if Stanza::is_defn(first_line) {
+                    Ok(Self::Defn(s))
+                } else if Stanza::is_note(first_line) {
+                    Ok(Self::Note(s))
+                } else if Stanza::is_synonym(first_line) {
+                    Ok(Self::Synonym(s))
+                } else if Stanza::is_bullet(first_line) {
+                    Ok(Self::Bullet(s))
+                } else if Stanza::is_sub_bullet(first_line) {
+                    Ok(Self::SubBullet(s))
+                } else {
+                Err(Self::Err {
+                    data: format!("weird stanza: {}", s),
+                })
+                }
+            } else {
+                Err(Self::Err {
+                    data: format!("empty first line: {}", s),
+                })
+            }
+        } else {
+            Err(Self::Err {
+                data: format!("empty stanza: {}", s),
+            })
+        }
+    }
+}
+