[Grammar] Prototype of the grammar of Oak with advanced syntax and capabilities, not yet implemented. Related to #42.

Author: ptal

src/bootstrap/oak_grammar.rs

@@ -0,0 +1,101 @@
+// Copyright 2016 Pierre Talbot (IRCAM)
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// WARNING: This is not a current valid Oak grammar. This is design experimentation on the grammar's evolution.
+
+pub use self::oak::*;
+
+grammar! oak {
+  type Stream = RustTokens;
+  type Context = FGrammar;
+  type ErrorContext = SyntaxErrorContext;
+
+  extern .alloc_expr -> usize;
+  extern .warning -> ();
+
+  grammar = block*
+
+  block = rs_inner_attrs item
+
+  rs_inner_attrs -> ()
+    = ::inner_attributes > .push_attributes
+
+  item -> ()
+    = ::parse_item > .push_rust_item
+    / rule
+
+  rule -> ()
+    = .. ::outer_attributes rule_decl "=" rule_rhs > .push_rule
+
+  rule_decl -> SpannedIdent
+    = .. ::ident > respan !> .current_rule
+
+  rule_rhs = .. choice > .alloc_expr
+
+  choice
+    = branch % "/" > Expression::Choice
+
+  branch
+    = sequence !">" !"->"
+    / .. sequence ">" ::ident > SemanticAction > .alloc_expr
+    / .. sequence "->" ty > TypeAscription > .alloc_expr
+
+  ty
+    = "()" > IType::unit
+    / "(^)" > IType::Invisible
+    \ "" !> UnknownTypeAscription
+
+  sequence
+    = syntactic_predicate !syntactic_predicate
+    / .. (syntactic_predicate+ > Sequence) > .alloc_expr
+    \ .. !syntactic_predicate !> EmptyRuleBodyError
+
+  syntactic_predicate
+    = .. "!" repeat > NotPredicate > .alloc_expr
+    / .. "&" repeat > AndPredicate > .alloc_expr
+    \ .. ("!" / "&") !repeat !> SyntacticPredicateExpectExpr
+    / repeat
+
+  repeat
+    = .. atom "*" > ZeroOrMore > .alloc_expr
+    / .. atom "+" > OneOrMore > .alloc_expr
+    / .. atom "?" > ZeroOrOne > .alloc_expr
+    / atom
+
+  atom
+    = .. (::cooked_literal > StrLiteral) > .alloc_expr
+    / .. ("." > AnySingleChar) > .alloc_expr
+    / "(" rule_rhs ")"
+    / .. (!::parse_item !rule_lhs ::ident > NonTerminalSymbol) > .alloc_expr
+    / "[" char_class "]"
+
+  char_class =
+    \ .. !"]" !> MissingStringLiteral
+    / .. ::cooked_literal ~> ::char_range_set > .alloc_expr
+}
+
+grammar! char_class {
+  type ErrorContext = SyntaxErrorContext;
+
+  char_range_set -> CharacterClassExpr
+    = .. warning_both_sep "-"? char_range* "-"? > CharacterClassExpr::full_range
+
+  char_range -> CharacterInterval =
+    \ "-" &. !> BadCharClassSeparator
+    / . "-" . > CharacterInterval::new
+    / !"-" . > CharacterInterval::single
+
+  warning_both_sep -> ()
+    = &("-" char_range* "-") !> WarningCharClassDoubleSep !> .warning
+}

tests/grammars/combinators.rs

@@ -16,6 +16,7 @@ pub use self::combinators::*;
 
 grammar! combinators {
   // #![debug_api]
+  #![show_api]
 
   str_literal = "return"