🐐 String interpolation

language/main.tex

@@ -61,6 +61,7 @@
         \languageline{expression}{\textit{expression} \textbf{binop} \textit{expression}} \\
         \languageline{expression}{\textbf{unop} \textit{expression}} \\ \hline
         \languageline{literal}{\textbf{string}} \\
+        \languageline{literal}{\textbf{interpolated-string}} \\
         \languageline{literal}{\textbf{numeral}} \\
         \languageline{literal}{\textbf{bool}} \\
         \languageline{literal}{\texttt{[} \textit{optional-expressions} \texttt{]}} \\
@@ -88,7 +89,8 @@
   \item \textbf{module-name}: \\ Modules are flags given to the interpreter/compiler, to let it know you want to be using certain rules, functions, or features.
   \item \textbf{id}: \\ Variable. Can only consist of lowercase characters and underscores, but not the letters j, u, or w.
   \item \textbf{builtin}: \\ Builtin functions are uppercase latin words.
-  \item \textbf{string}: \\ Any text encased in " characters.
+  \item \textbf{string}: \\ Any text encased in \texttt{"} or \texttt{'} characters. Single-quoted strings are always literal.
+  \item \textbf{interpolated-string}: \\ A double-quoted string containing \texttt{\{}\textit{expression}\texttt{\}} segments. Each expression is evaluated and coerced to a string. Use \texttt{\{\{} and \texttt{\}\}} for literal braces.
   \item \textbf{numeral}: \\ Roman numerals consisting of the uppercase characters I, V, X, L, C, D, and M. Can also include underscore if the module MAGNVM.
   \item \textbf{bool}: \\ VERITAS or FALSITAS.
   \item \textbf{binop}: \\ Binary operators: \texttt{+}, \texttt{-}, \texttt{*}, \texttt{/}, \texttt{RELIQVVM} (modulo), \texttt{EST} (equality), \texttt{DISPAR} (not-equal), \texttt{MINVS} (<), \texttt{PLVS} (>), \texttt{ET} (and), \texttt{AVT} (or), \texttt{\&} (string concatenation).