broken code, but added attempt at writing grammar

src/msph/README.md

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+# msph/micro sappho
+
+Micro sappho is a minimalistic language for demonstration of the SPHO type
+system. It is implemented using a simple parser and lexer that implements the
+grammar below. The indended use is to allow experimentation and familiarization
+with the SPHO types and subtyping.
+
+## Grammar
+
+Grammar in pseudo-bnf
+
+```
+
+MSph ::= Body
+
+Body ::= Dirs
+
+Dir ::= Typedef             (directives, with lack of a better name)
+      | Memberdef
+      | Nominaldecl
+      | Checkdir
+
+Typedef ::= 'type' Name '=' TExpr                   (type definition/binding)
+          | 'type' Name '[' Names ']' '=' TExpr
+          | 'type' Name                             (declaration, donno if useful)
+
+Memberdef ::= 'member' Name ':' TExpr
+
+Nominaldecl ::= 'nominal' Name
+
+Checkdir ::= 'check' TExpr '<:' TExpr
+
+TExpr ::= 'True'
+        | 'False'
+        | Var
+        | Nominal
+        | Trait
+        | TExpr '&' TExpr
+        | TExpr '|' TExpr
+        | TExpr '=>' TExpr
+        | TExpr '->' TExpr
+        | 'box' TExpr
+        | 'forall' Name '.' TExpr
+        | '(' TExpr ')'
+
+Trait ::= '{' Body '}'                  (trait, this introduces scoping)
+
+Var ::= Name                            (type variables)
+Nominal ::= Name                        (nominal type)
+
+Name ::= '[a-zA-Z0-9_]+' & !Reserved     (name/identifier)
+
+Reserved ::= 'type'                     (reserved/keywords)
+           | 'member'
+           | 'nominal'
+           | 'check'
+           | 'forall'
+           | 'box'
+           | 'True'
+           | 'False'
+```
+
+Precedence of binary operators:
+'&'  <
+'|'  <
+'->' <
+'=>'
+
+< means "binds closer"
+
+## Example
+
+A simple example msph program
+
+```
+
+nominal ExampleN
+
+type ExampleDecl
+type ExampleDecl2
+
+type Example = {
+    member example_m : C -> C
+    type FA = forall X. X -> X
+
+    type b = forall X. (box X => ExampleDecl) => ExampleDecl2
+}
+
+member example_global : Example & ExampleN
+
+type TripleConj[X, Y, Z] = X & Y & Z
+
+```