grammar reference

doc/src/conf.py

@@ -32,6 +32,7 @@ html_theme = 'alabaster'
 imgmath_latex_preamble = r'''
 \usepackage{amsmath}
 \usepackage{tabularray}
+\usepackage{syntax}
 
 \newcommand{\transrule}[2]
     {\begin{tblr}{|rrrlc|}

doc/src/references/rlp-grammar.rst

@@ -0,0 +1,67 @@
+The Complete Syntax of rl'
+==========================
+
+WIP.
+
+Provided is the complete syntax of rl' in (pseudo) EBNF. {A} represents zero or
+more A's, [A] means optional A, and terminals are wrapped in 'single-quotes'.
+
+.. math
+   :nowrap:
+
+   \setlength{\grammarparsep}{20pt plus 1pt minus 1pt}
+   \setlength{\grammarindent}{12em}
+   \begin{grammar}
+       <Decl> ::= <InfixDecl>
+       \alt <DataDecl>
+       \alt <TypeSig>
+       \alt <FunDef>
+
+       <InfixDecl> ::= <InfixWord> `litint' <Name>
+       <InfixWord> ::= `infix'
+       \alt `infixl'
+       \alt `infixr'
+
+       <DataDecl> ::= `data' `conname' {}
+
+   \end{grammar}
+
+.. code-block:: bnf
+
+   Decl      ::= InfixDecl
+               | DataDecl
+               | TypeSig
+               | FunDef
+
+   InfixDecl ::= InfixWord 'litint' Operator
+   InfixWord ::= 'infix'
+               | 'infixl'
+               | 'infixr'
+
+   DataDecl  ::= 'data' 'conname' {'name'} '=' Data
+   DataCons  ::= 'conname' {Type1} ['|' DataCons]
+
+   TypeSig   ::= Var '::' Type
+   FunDef    ::= Var {Pat1} '=' Expr
+
+   Type      ::= Type1 {Type1}
+               -- note that (->) is right-associative,
+               -- and extends as far as possible
+               | Type '->' Type
+   Type1     ::= '(' Type ')'
+               | 'conname'
+
+   Pat       ::= 'conname' Pat1 {Pat1}
+               | Pat 'consym' Pat
+
+   Pat1      ::= Literal
+               | 'conname'
+               | '(' Pat ')'
+
+   Literal   ::= 'litint'
+
+   Var ::= 'varname'
+         | '(' 'varsym' ')'
+   Con ::= 'conname'
+         | '(' 'consym' ')'
+