Enum

GRAMMER.md

@@ -4,145 +4,170 @@
 **      use a tool to validate this...**
 
 ## Statements
-```
-Stmt     ::= ExprStmt | WhileLoop | DoWhileLoop |
-             ForLoop | IfElse | Declaration | 
-             Block .
-Chunk    ::= {Stmt [";"]} [LastStmt [";"]] .
-Block    ::= "{" Chunk "}" .
-LastStmt ::= "return" [Expr] | "continue" | "break" .
-ExprStmt ::= Operand "=" Expr | Call | Match .
+```ebnf
+Stmt     = ExprStmt | WhileStmt | DoWhileStmt |
+           ForStmt | IfElse | Declaration | 
+           Block .
+Chunk    = {Stmt [";"]} [LastStmt [";"]] .
+Block    = "{" Chunk "}" .
+LastStmt = "return" [Expr] | "continue" | "break" .
+ExprStmt = Operand "=" Expr | Call | Match .
 ```
 
 ### Control flow
-```
-IfElse      ::= "if" Expr Block [{"else" IfElse} | "else" Block] .
-WhileLoop   ::= "while" Expr Block .
-DoWhileLoop ::= "do" Block "while" Expr .
-ForLoop     ::= ForIn | ForNum .
-ForIn       ::= "for" name "in" Expr Block .
-ForNum      ::= "for" name "=" Expr "," Expr ["," Expr] Block .
-Match       ::= "match" Expr MatchBody .
-MatchBody   ::= "{" {MatchArm ","} MatchArm "}" .
-MatchClause ::= Expr "=>" MatchArm .
-MatchArm    ::= Expr | Block .
+```ebnf
+IfElse      = "if" Expr Block [{"else" IfElse} | "else" Block] .
+WhileStmt   = "while" Expr Block .
+DoWhileStmt = "do" Block "while" Expr .
+ForStmt     = ForIn | ForNum .
+ForIn       = "for" name "in" Expr Block .
+ForNum      = "for" name "=" Expr "," Expr ["," Expr] Block .
 ```
 
-## Declarations
+## Pattern matching
+```ebnf
+MatchExpr   = "match" Expr MatchBody .
+MatchBody   = "{" {MatchArm ","} MatchArm "}" .
+MatchClause = Pattern "=>" MatchArm .
+MatchArm    = Expr | Block .
 ```
-Declaration ::= VarDecl | FunctionDecl |
-                ClassDecl | EnumDecl | TypeDecl .
-VarDecl     ::= "let" name [":" Type] "=" Expr .
-TypeDecl    ::= "type" name [TypeParam] "=" Type .
-TypeParam   ::= "[" {name ","} name "]" .
+
+## Paths
+TODO: 'Suffixed expressions' can be split up into a path, possibly followed by a '.', '?', '(', or '{'.
+TODO: The suffix after the path cannot contain '::', since any of the aformentioned tokens resolve to a value, as opposed to a type
+```ebnf
+Path    = {Segment "::"} Segment .
+Segment = name [TypeArgs] .
 ```
 
-### Functions
+## Patterns
+```ebnf
+Pattern = LiteralPat | TuplePat | StructPat | 
+          VariantPat | PathPat | RangePat .
+LiteralPat = StrPat | IntPat | BoolPat .
+RangePat = Pattern RangeSep Pattern .
+RangeSep = ".." | "..=" .
+PatList = {Pattern ","} Pattern [","] .
+TuplePat = "(" [{Pattern ","} Pattern "," [Pattern]] ")".
+VariantPat = Path "(" PatList ")" .
+StructPat = Path "{" PatList "}" .
+PathPat = Path .
 ```
-FunctionDecl ::= "fn" Function .
-Function     ::= name [TypeParam] FuncType Block .
-FuncType    ::= "(" [{Field ","} Field] ")" ["->" Type] .
-Field        ::= name ":" Type .
+
+## Declarations
+```ebnf
+Declaration = VarDecl | FunctionDecl | StructDecl | 
+              EnumDecl | TypeDecl .
+VarDecl     = "let" name [":" Type] "=" Expr .
+TypeDecl    = "type" name [Generics] "=" Type .
+Generics    = "[" {name ","} name "]" .
 ```
 
-### Classes
+### Functions
+```ebnf
+FunctionDecl = "fn" Function .
+Function     = name [Generics] FuncHead Block .
+FuncHead     = "(" [{Field ","} Field] ")" ["->" Type] .
+Field        = name ":" Type .
 ```
-ClassDecl ::= "class" ClassType .
-ClassType ::= name [TypeParam] ClassBody .
-ClassBody ::= "{" {Attribute [";"]} "}" .
-Attribute ::= Method | Field .
-Method    ::= ["static"] Function .
+
+### Structures
+```ebnf
+StructDecl = "struct" name [Generics] StructBody .
+StructBody = "{" {Field [";"]} "}" .
 ```
 
 ### Enumerators
-```
-EnumDecl ::= "enum" name EnumBody .
-EnumBody ::= "{" [{Variant ","} Variant] "}" .
-Variant  ::= name [Payload] .
-Payload  ::= "(" {Type ","} Type ")" .
+```ebnf
+EnumDecl = "enum" name [Generics] EnumBody .
+EnumBody = "{" [{Variant ","} Variant] "}" .
+Variant  = name [Payload] .
+Payload  = "(" {Type ","} Type ")" .
 ```
 
 ## Operators
-```
-BinOp ::= "+" | "-" | "*" | "/" |
-          "%" | "&" | "^" | "|" |
-          "<" | "<=" | ">" | ">=" | 
-          "==" | "!=" | "&&" | "||" .
-UnOp  ::= "-" | "~" | "!" | "#" .
+```ebnf
+BinOp = "+" | "-" | "*" | "/" |
+        "%" | "&" | "^" | "|" |
+        "<" | "<=" | ">" | ">=" | 
+        "==" | "!=" | "&&" | "||" .
+UnOp  = "-" | "~" | "!" | "#" .
 ```
 
 ## Expressions
-```
-Expr        ::= PrimaryExpr | Expr BinOp Expr | UnOp Expr . 
-PrimaryExpr ::= Operand | Call | Literal | "(" Expr ")" .
-Call        ::= PrimaryExpr "(" [ExprList] ")" .
-Operand     ::= name | Index | Selector .
-Index       ::= PrimaryExpr "[" ExprList "]" .
-Selector    ::= PrimaryExpr "." name .
-ExprList    ::= {Expr ","} Expr .
+```ebnf
+Expr        = PrimaryExpr | Expr BinOp Expr | UnOp Expr . 
+PrimaryExpr = Operand | Call | "(" Expr ")" .
+Call        = PrimaryExpr "(" [ExprList] ")" .
+Index       = PrimaryExpr "[" ExprList "]" .
+Selector    = PrimaryExpr "." name .
+ExprList    = {Expr ","} Expr .
 ```
 
 ## Types
-```
-Type      ::= name [TypeArgs] | TypeLit .
-TypeLit   ::= FuncType | ArrayType | TupleType .
-FuncType  ::= "fn" "(" [TypeList] ")" ["->" Type] .
-TypeList  ::= {Type ","} Type
-TypeArgs  ::= "[" TypeList "]" .
-NamedType ::= name [TypeArgs] .
-ArrayType ::= "[" Type ";" int_lit "]" .
-TupleType ::= "(" [Type "," [Type]] ")" . 
+```ebnf
+Type       = NamedType | TypeLit .
+TypeLit    = FuncType | VectorType | MapType | 
+             TupleType | NamedType .
+FuncType   = "fn" "(" [TypeList] ")" ["->" Type] .
+TypeList   = {Type ","} Type .
+TypeArgs   = "[" TypeList "]" .
+NamedType  = name [TypeArgs] .
+VectorType = "[" Type "]" .
+MapType    = "[" Type ":" Type "]" .
+TupleType  = "(" [{Type ","} Type "," [Type]] ")".
 ```
 
 ## Operands
-```
-Operand  ::= Literal | name [TypeArgs] .
-Literal  ::= BasicLit | CompositeLit .
-BasicLit ::= int_lit | bool_lit | float_lit | string_lit .
+```ebnf
+Operand  = Path | Index | Selector | Literal .
+Literal  = BasicLit | CompositeLit .
+BasicLit = int_lit | bool_lit | float_lit | string_lit .
 ```
 
 ### Composite literals
 Note that the unit type is just a 0-tuple (an tuple with 0 elements).
 A 1-tuple must have a trailing `,` to distinguish it from a parenthesized expression.
-```
-CompositeLit ::= ClassLit | ArrayLit | TupleLit | VariantLit .
-ClassLit     ::= NamedType "{" [ItemList [","]] "}" .
-ArrayLit     ::= "[" [ExprList [","]] "]" .
-TupleLit     ::= "(" [Expr "," [Expr [","]]] ")" .
-VariantLit   ::= name ["(" {Expr ","} Expr ")"] .
-ItemList     ::= KeyedItem {"," KeyedItem} [","] .
-KeyedItem    ::= [Key ":"] Expr .
-Key          ::= name | Expr .
+```ebnf
+CompositeLit = VectorLit | MapLit | TupleLit | StructLit | VariantLit .
+VectorLit    = "[" [ExprList [","]] "]" .
+MapLit       = "[" ":" "]" | "[" [ItemList [","]] "]" .
+TupleLit     = "(" [{Expr ","} Expr "," [Expr]] ")".
+StructLit    = Path "{" [ItemList [","]] "}" .
+VariantLit   = Path ["(" {Expr ","} Expr ")"] .
+ItemList     = KeyedItem {"," KeyedItem} [","] .
+KeyedItem    = [Key ":"] Expr .
+Key          = name | Expr .
 ```
 
 ### Integer literals
-```
-int_lit        ::= decimal_lit | binary_lit | octal_lit | hex_lit .
-decimal_lit    ::= "0" | ("1" … "9") [decimal_digits] .
-binary_lit     ::= "0" ("b" | "B") binary_digits .
-octal_lit      ::= "0" ("o" | "O") octal_digits .
-hex_lit        ::= "0" ("x" | "X") hex_digits .
+```ebnf
+int_lit        = decimal_lit | binary_lit | octal_lit | hex_lit .
+decimal_lit    = "0" | ("1" … "9") [decimal_digits] .
+binary_lit     = "0" ("b" | "B") binary_digits .
+octal_lit      = "0" ("o" | "O") octal_digits .
+hex_lit        = "0" ("x" | "X") hex_digits .
 ```
 
 ### Float literals
-```
-float_lit        := decimal_digits "." [decimal_digits] [decimal_exponent] |
-                    decimal_digits decimal_exponent |
-                    "." decimal_digits [decimal_exponent] .
-decimal_exponent := ("e" | "E") ["+" | "-"] decimal_digits .
+```ebnf
+float_lit        = decimal_digits "." [decimal_digits] [decimal_exponent] |
+                   decimal_digits decimal_exponent |
+                   "." decimal_digits [decimal_exponent] .
+decimal_exponent = ("e" | "E") ["+" | "-"] decimal_digits .
 ```
 
 ## Miscellaneous
-```
-name           ::= letter {letter | decimal_digit} .
-letter         ::= "A" … "Z" | "a" … "z" | "_" .
-decimal_digit  ::= "0" … "9" .
-binary_digit   ::= "0" | "1" .
-octal_digit    ::= "0" … "7" .
-hex_digit      ::= "0" … "9" | "A" … "F" | "a" … "f" .
-decimal_digits ::= decimal_digit {decimal_digit} .
-binary_digits  ::= binary_digit {binary_digit} .
-octal_digits   ::= octal_digit {octal_digit} .
-hex_digits     ::= hex_digit {hex_digit} .
+```ebnf
+name           = letter {letter | decimal_digit} .
+letter         = "A" … "Z" | "a" … "z" | "_" .
+decimal_digit  = "0" … "9" .
+binary_digit   = "0" | "1" .
+octal_digit    = "0" … "7" .
+hex_digit      = "0" … "9" | "A" … "F" | "a" … "f" .
+decimal_digits = decimal_digit {decimal_digit} .
+binary_digits  = binary_digit {binary_digit} .
+octal_digits   = octal_digit {octal_digit} .
+hex_digits     = hex_digit {hex_digit} .
 ```