Rework the language syntax.

Split into command mode and expression mode.

ideas

@@ -1,3 +1,20 @@
+Math mode:
+
+Stop comingling math and regular "shell" syntax. Use m() to enter math mode, e.g
+
+$foo = m($foo + $bar)
+
+in math mode, +, -, *, /, and ^ perform math operations. Outside math mode, the do not.
+
+Outside of math mode, * is the wildcard operator.
+
+Similarly, we drop regular expression literals and switch to regular expression mode, e.g.
+
+re(.*)
+
+Regular expression mode is similar to "regular" eregexes, but are whitespace insensitive (use backslash + space
+for a space, \n for a newline, etc. regexp mode still has comments.
+
 Graphs:
 
 Graphs consist of two data types: nodes and edges.

src/lang/ast/location.rs

@@ -26,3 +26,12 @@ impl Location {
         self.end - self.start
     }
 }
+
+impl From<usize> for Location {
+    fn from(value: usize) -> Self {
+        Location{
+            start: value,
+            end: value+1
+        }
+    }
+}