Introduce pmp-core crate: provide shared proc-macro utilities, strict attribute parsing, and reusable helpers for pmp-* crates.

crates/pmp-core/src/functions.rs

@@ -0,0 +1,26 @@
+
+pub fn pascal_to_title(s: &str) -> String
+{
+    let mut out = String::new();
+
+    for (i, ch) in s.chars().enumerate() {
+        if ch.is_uppercase() && i > 0 { out.push(' '); }
+        out.push(ch);
+    }
+
+    out
+}
+
+pub fn snake_to_title(s: &str) -> String
+{
+    s.split('_')
+        .map(|word| {
+            let mut c = word.chars();
+            match c.next() {
+                None    => String::new(),
+                Some(f) => f.to_uppercase().collect::<String>() + c.as_str(),
+            }
+        })
+        .collect::<Vec<_>>()
+        .join(" ")
+}