Initial Commit

Working base grammar, visitor, client, context.
Good test coverage for grammar constructs.

assets/grammar.ppeg

@@ -0,0 +1,56 @@
+command = "${" component "}"
+
+cmdarg = "$" ~r"\d+\*?"
+
+
+parenthised = ("(" component ")") / ("{" component "}")
+true = "True" / "true"
+false = "False" / "false"
+bool = true / false
+
+basicterm = bool / numeric / parenthised / quoted / cmdarg / var
+term = ws* (function / basicterm) ws*
+
+var = (parenthised / keyword) ("." keyword)*
+function = var (ws+ basicterm)+
+
+type = keyword
+typecast = basicterm "::" type
+
+test_eq = term "==" term
+test_neq = term "!=" term
+test_gt = term ">" term
+test_geq = term ">=" term
+test_lt = term "<" term
+test_leq = term "<=" term
+test = (test_eq/test_neq/test_gt/test_geq/test_lt/test_leq)
+
+op_or = term ("||" term)+
+op_and = term ("&&" term)+
+op_add = term ("+" term)+
+op_minus = term ("-" term)+
+op_times = term ("*" term)+
+op_exp = term ("**" term)+
+op_divide = term ("/" term)+
+op_div = term ("//" term)+
+op_mod = term ("%" term)+
+binop = (op_or/op_and/op_add/op_minus/op_times/op_exp/op_divide/op_div/op_mod)
+
+
+cascade = term ("|" term)+
+
+ternary = term "?" term ":" term
+ifthenelse = "if" ws term ws "then" ws term (ws "elif" ws term ws "then" ws term)* (ws "else" ws term)? "fi"
+
+equals = keyword ws* '=' ws* term
+defines = keyword ws* ":=" ws* term
+definesterm = keyword ws* "::=" ws* term
+
+component = ws* (cascade / ternary / equals / defines / definesterm / binop / test / term) ws*
+
+
+word = ~r"[_\w]+"
+keyword = word
+quoted = ~'"[^\"]*"'
+numeric = ~r"[\d]+"
+ws = ~r"\s+"