Allow iteration in arithmetic expressions

Wasm-DSL · Nov 28, 2023 · d2966be · d2966be
1 parent 613c768
commit d2966be
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Showing 4 changed files with 33 additions and 3 deletions.
diff --git a/spectec/doc/Language.md b/spectec/doc/Language.md
@@ -161,8 +161,10 @@ arith ::=
   arith cmpop arith                    comparison
   exp "[" arith "]"                    list indexing
   "(" arith ")"                        parentheses
+  "(" arith iter ")"                   iteration (must not be "^exp")
   "|" exp "|"                          list length
   "$" defid exp?                       function invocation
+  "$" "(" exp ")"                      escape back to general expression syntax
 
 path ::=
   path? "[" arith "]"                  list element

diff --git a/spectec/src/frontend/parser.mly b/spectec/src/frontend/parser.mly
@@ -61,7 +61,7 @@ let strip_ticks id =
   String.sub id 0 !i
 
 
-(* Parentheses Role *)
+(* Parentheses Role etc *)
 
 type prec = Op | Seq | Post | Prim
 
@@ -86,6 +86,18 @@ let signify_pars prec = function
   | ParenE (exp, false) -> ParenE (exp, prec < prec_of_exp exp.it)
   | exp' -> exp'
 
+let is_post_exp e =
+  match e.it with
+  | VarE _ | AtomE _
+  | BoolE _ | NatE _ | HexE _ | CharE _
+  | EpsE
+  | ParenE _ | TupE _ | BrackE _
+  | IdxE _ | SliceE _ | ExtE _
+  | StrE _ | DotE _
+  | IterE _ | CallE _
+  | HoleE _ -> true
+  | _ -> false
+
 %}
 
 %token LPAR RPAR LBRACK RBRACK LBRACE RBRACE
@@ -517,6 +529,22 @@ arith_prim_ :
   | INT { VarE ("int" $ at $sloc) }
   | TEXT { VarE ("text" $ at $sloc) }
   | LPAR arith RPAR { ParenE ($2, false) }
+  | LPAR arith_bin STAR RPAR
+    { (* HACK: to allow "(s*)" as arithmetic expression. *)
+      if not (is_post_exp $2) then
+        Source.error (at $loc($3)) "syntax" "misplaced token";
+      IterE ($2, List) }
+  | LPAR arith_bin PLUS RPAR
+    { (* HACK: to allow "(s+)" as arithmetic expression. *)
+      if not (is_post_exp $2) then
+        Source.error (at $loc($3)) "syntax" "misplaced token";
+      IterE ($2, List1) }
+  | LPAR arith_bin QUEST RPAR
+    { (* HACK: to allow "(s?)" as arithmetic expression. *)
+      if not (is_post_exp $2) then
+        Source.error (at $loc($3)) "syntax" "misplaced token";
+      IterE ($2, Opt) }
+  | DOLLAR LPAR exp RPAR { $3.it }
   | DOLLAR defid { CallE ($2, TupE [] $ at $sloc) }
   | DOLLAR defid_lpar exp_list RPAR { CallE ($2, tup_exp $3 $loc($3)) }
 

diff --git a/spectec/test-latex/Makefile b/spectec/test-latex/Makefile
@@ -6,7 +6,7 @@ EXT = $(NAME)
 
 OWNDIR = $(PWD)
 SPECDIR = ../spec
-SPECS = $(shell ls $(SPECDIR))
+SPECS = $(shell cd $(SPECDIR) && ls -d wasm-*)
 SPECFILES = $(shell ls $(SPECS:%=$(SPECDIR)/%/*.$(EXT)))
 
 SPEC = 

diff --git a/spectec/test-prose/Makefile b/spectec/test-prose/Makefile
@@ -6,7 +6,7 @@ EXT = $(NAME)
 
 OWNDIR = $(PWD)
 SPECDIR = ../spec
-SPECS = $(shell ls $(SPECDIR))
+SPECS = $(shell cd $(SPECDIR) && ls -d wasm-*)
 TESTS = $(SPECS:%=test-%)