TreeDL: basic scoping (#505)

* local vars

* var decls

* scope parent

* bind attrs

* make grammar more compact

languageWorkbench/languages/treeDL/example.txt

@@ -2,16 +2,4 @@ rule {
   raw_node = rawNode()
   id = raw_node.id
   node = Node.add(id=id)
-  rule {
-    next = Node()
-    raw_next = raw_node.next
-    next == raw_next
-    node.set(next=next)
-  }
-  rule {
-    prev = Node()
-    raw_prev = raw_node.prev
-    prev == raw_prev
-    node.set(prev=prev)
-  }
 }

languageWorkbench/languages/treeDL/treeDL.dl

@@ -1,3 +1,45 @@
+# Var
+
+scope.Var{scopeID: I, name: N, span: S, kind: K} :-
+  var.localVar{scopeID: I, name: N, span: S, kind: K}.
+var.localVar{scopeID: Statement, name: N, span: S, kind: "var"} :-
+  ast.Statement{id: Statement} &
+  ast.Assign{id: Assign, parentID: Statement} &
+  ast.Expr{id: Expr, parentID: Assign} &
+  var.expr{id: Expr, name: N, span: S}.
+var.expr{id: I, name: N, span: S} :-
+  var.memberAccess{id: I, name: N, span: S} |
+  var.bindAttr{id: I, name: N, span: S}.
+var.memberAccess{id: Expr, name: N, span: span{from: Start, to: End}} :-
+  ast.Expr{id: Expr} &
+  ast.MemberAccess{id: MemberAccess, parentID: Expr, span: span{from: Start}} &
+  ast.Ident{parentID: MemberAccess, text: N, span: span{from: Start, to: End}}.
+var.bindAttr{id: Expr, name: N, span: span{from: Start, to: End}} :-
+  ast.Expr{id: Expr} &
+  ast.Bind{id: Bind, parentID: Expr} &
+  ast.Attrs{id: Attrs, parentID: Bind} &
+  ast.Attr{id: Attr, parentID: Attrs, span: span{to: End}} &
+  ast.Ident{parentID: Attr, text: N, span: span{from: Start, to: End}}. # TODO: use 'key'
+
+# Defn
+
+scope.Defn{scopeID: I, span: S, name: N, kind: K, type: T} :-
+  defn.localVar{scopeID: I, span: S, name: N, kind: K, type: T}.
+
+defn.localVar{scopeID: Statement, span: S, name: N, kind: "var", type: "any"} :-
+  ast.Statement{id: Statement} &
+  ast.Assign{id: Assign, parentID: Statement} &
+  ast.Ident{parentID: Assign, span: S, text: N}.
+
+# Parent
+
+scope.Parent{parentID: First, childID: Second} :-
+  ast.Statement{id: First} &
+  ast.Statement{id: Second} &
+  astInternal.next{prev: First, next: Second}.
+
+# Highlight
+
 hl.mapping{rule: "Ident", type: "ident"}.
 hl.mapping{rule: "NumberLit", type: "number"}.
 hl.mapping{rule: "BoolLit", type: "number"}.

languageWorkbench/languages/treeDL/treeDL.grammar

@@ -1,24 +1,10 @@
 main :- Rule.
 Program :- repSep(Rule, ws).
-Rule :- [
-  ruleKW,
-  ws,
-  "{",
-  ws,
-  Sequence,
-  ws,
-  "}"
-].
+Rule :- [ruleKW, ws, "{", ws, Sequence, ws, "}"].
 Sequence :- repSep(Statement, ws).
 Statement :- (Assign | Filter | Bind | Rule).
 Assign :- [Ident, ws, "=", ws, Expr].
-Filter :- [
-  Ident,
-  ws,
-  InfixOp,
-  ws,
-  Ident
-].
+Filter :- [Ident, ws, InfixOp, ws, Ident].
 Expr :- (
   MemberAccess |
   Literal |
@@ -29,22 +15,21 @@ Expr :- (
 MemberAccess :- repSep(Ident, ".").
 Call :- InfixCall.
 Get :- [Ident, Attrs].
-InfixCall :- [
-  Ident,
-  ws,
-  InfixOp,
-  ws,
-  Ident
-].
+InfixCall :- [Ident, ws, InfixOp, ws, Ident].
 PrefixCall :- [Ident, Attrs].
 Attrs :- ["(", repSep(Attr, CommaSpace), ")"].
-Attr :- [Ident, "=", Ident].
+Attr :- [key:Ident, "=", value:Ident].
 InfixOp :- ("+" | "-" | "*" | "/" | "==" | "!=" | "<" | "<=" | ">" | ">=").
 Bind :- [Ident, ".", addKW, Attrs].
 Literal :- (StringLit | NumberLit | BoolLit).
 
+# keywords
+ruleKW :- "rule".
+addKW :- "add".
+setKW :- "set".
 
-Ident :- [alpha, repSep((alphaNum | "."), "")].
+# stdlib
+Ident :- [alpha, repSep(alphaNum, "")].
 StringLit :- ["\"", repSep(stringChar, ""), "\""].
 NumberLit :- [("-" | ""), first:num, repSep(num, "")].
 BoolLit :- ("true" | "false").
@@ -57,9 +42,6 @@ spaces :- repSep(" ", "").
 placeholder :- "???".
 CommaSpace :- [",", ws].
 
-ruleKW :- "rule".
-addKW :- "add".
-setKW :- "set".
-
-commentChar :- ^'\n'.
 comment :- ["#", repSep(commentChar, "")].
+commentChar :- ^'\n'.
+