document parsers with their bnf

Author: quasarbright

src/ParseExpr.hs

@@ -9,6 +9,20 @@ import ParseUtils
 import ParseUnit
 
 
+{--
+<expr> = <expr> <binop> <expr>
+       | '-' <expr>
+       | '(' <expr> ')'
+       | <identifier> '(' <args>? ')'
+       | <expr> '::' <unit>
+       | <number>
+       | <identifier>
+
+<args> = <expr> | <expr> ',' <args>
+
+<binop> = [-+*/^]
+--}
+
 combineExprSS :: Expr SS -> Expr SS -> SS
 combineExprSS e1 e2 = combineSS (getTag e1) (getTag e2)
 

src/ParseProgram.hs

@@ -9,6 +9,32 @@ import Control.Applicative hiding (Const)
 import ParseExpr
 import ParseUnit
 
+{--
+<program> = <statement>*
+
+<statement> = 'def' <identifier> '=' <expression>
+            | 'var' <identifier> '::' <unit>
+            | 'derived' <identifier> '=' <unit>
+            | 'expr' <expr>
+            | 'eq' <expr> '=' <expr>
+
+<expr> = <expr> <binop> <expr>
+       | '-' <expr>
+       | '(' <expr> ')'
+       | <identifier> '(' <args>? ')'
+       | <expr> '::' <unit>
+       | <number>
+       | <identifier>
+
+<args> = <expr> | <expr> ',' <args>
+
+<binop> = [-+*/^]
+
+<unit> = '[' <basePow>* ']'
+
+<basePow> = <identifier> ('^' <integer>)?
+--}
+
 program :: Parser (Program SS)
 program = Program <$> many statement <?> "program"
 

src/ParseUnit.hs

@@ -7,6 +7,12 @@ import qualified Text.Parsec.Token as P
 import Control.Applicative hiding (Const)
 import qualified Data.Maybe as Maybe
 
+{--
+<unit> = '[' <basePow>* ']'
+
+<basePow> = <identifier> ('^' <integer>)?
+--}
+
 baseOfString :: String -> SS -> BaseUnit SS
 baseOfString s = Maybe.fromMaybe (Derived s) (lookup s siMap)
     where