// The FLEET Assembly Language Grammar
// As specified in document 2005-ucies06

// comments are included where the grammar had to go beyond the strict
// "letter of the law" in ies06

// Note that this is the *entire, complete* formal specification of
// the grammar.  An equivalent lex+yacc grammar and support code would
// be several times as long.

Comment     !  = "//" ~[\n]* "\n"
               | "/*" ~[\n]* "*/"

ws             = w**
w              = [\r\n ]
               | Comment

Program        = Statement+                            /ws

Statement      = Move ";"?                             /ws
               | "{" Statement* "}"
               | Port "RENAMES" Port "ENDRENAME" ";"   /ws
//             | "#define" Port Port                   /ws

Move           = Source       ^"->" Destination        /ws
               | Source       ^"=>" Destination        /ws
               | Destination  ^":=" Source             /ws

Destination    = Port +/ (ws "," ws)
Source         = Port
               | CodeBag

CodeBag        = CodeBagName? "{" Statement* "}" ";"?  /ws

// Note: this deviates from ies06
Port           = shipname ("." portname)*
shipname       = name     index?
portname       = name     index?
name           = [A-Za-z] [A-Za-z0-9\[\]\.]*
index          = "[" [0-9]+ "]"
               | [0-9]+


//
// The syntax should be rather self-explanatory; here are some of the
// grammatical operators you may not have seen before:
// 
//   ^     marks the "key" token; this is used only after parsing
//   /     separated-by; all preceding elements are separated by the following element
//   +/    one-or-more-with-separator; for example, "a"+/"," matches "a,a,a"
//   */    zero-or-more-with-separator
//   &     intersection; a&b matches a string only if a matches it and b matches it
//   &~    negated intersection; a&~b matches a string only if a matches it and b DOES NOT match it
//