Better "unexpected kw" handling in ternary parsing

JuliaLang · Aug 25, 2022 · 424be21 · 424be21
1 parent 291da24
commit 424be21
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Showing 3 changed files with 23 additions and 9 deletions.
diff --git a/src/kinds.jl b/src/kinds.jl
@@ -27,15 +27,10 @@ const _kind_names =
         "baremodule"
         "begin"
         "break"
-        "catch"
         "const"
         "continue"
         "do"
-        "else"
-        "elseif"
-        "end"
         "export"
-        "finally"
         "for"
         "function"
         "global"
@@ -51,6 +46,13 @@ const _kind_names =
         "try"
         "using"
         "while"
+        "BEGIN_BLOCK_CONTINUATION_KEYWORDS"
+            "catch"
+            "finally"
+            "else"
+            "elseif"
+            "end"
+        "END_BLOCK_CONTINUATION_KEYWORDS"
         "BEGIN_CONTEXTUAL_KEYWORDS"
             # contextual keywords
             "abstract"
@@ -1045,6 +1047,7 @@ end
 is_contextual_keyword(k::Kind) = K"BEGIN_CONTEXTUAL_KEYWORDS" < k < K"END_CONTEXTUAL_KEYWORDS"
 is_error(k::Kind) = K"BEGIN_ERRORS" < k < K"END_ERRORS"
 is_keyword(k::Kind) = K"BEGIN_KEYWORDS" < k < K"END_KEYWORDS"
+is_block_continuation_keyword(k::Kind) = K"BEGIN_BLOCK_CONTINUATION_KEYWORDS" < k < K"END_BLOCK_CONTINUATION_KEYWORDS"
 is_literal(k::Kind) = K"BEGIN_LITERAL" < k < K"END_LITERAL"
 is_operator(k::Kind) = K"BEGIN_OPS" < k < K"END_OPS"
 is_word_operator(k::Kind) = (k == K"in" || k == K"isa" || k == K"where")
@@ -1098,5 +1101,3 @@ end
 function is_whitespace(x)
     kind(x) in (K"Whitespace", K"NewlineWs")
 end
-
-
diff --git a/src/parser.jl b/src/parser.jl
@@ -659,8 +659,18 @@ function parse_cond(ps::ParseState)
     t = peek_token(ps)
     if !preceding_whitespace(t)
         # a ? b :c  ==>  (if a [ ] [?] [ ] b [ ] [:] (error-t) c)
-        bump_invisible(ps, K"error", TRIVIA_FLAG,
-                       error="space required after `:` in `?` expression")
+        bump_invisible(ps, K"error", TRIVIA_FLAG, error="space required after `:` in `?` expression")
+    end
+    if is_block_continuation_keyword(kind(t))
+        # a "continuaton keyword" is likely to belong to the surrounding code, so
+        # we abort early
+
+        # if true; x ? true elseif true end  ==> (if true (block (if x true (error-t) (error-t))) (elseif true (block)))
+        # if true; x ? true end  ==> (if true (block (if x true (error-t) (error-t))))
+        # if true; x ? true : elseif true end  ==> (if true (block (if x true (error-t))) (elseif true (block)))
+        bump_invisible(ps, K"error", TRIVIA_FLAG, error="unexpected `$(kind(t))`")
+        emit(ps, mark, K"if")
+        return
     end
     parse_eq_star(ps)
     emit(ps, mark, K"if")

diff --git a/test/parser.jl b/test/parser.jl
@@ -402,6 +402,9 @@ tests = [
         "if a xx elseif b yy end"   =>  "(if a (block xx) (elseif b (block yy)))"
         "if a xx else if b yy end"  =>  "(if a (block xx) (error-t) (elseif b (block yy)))"
         "if a xx else yy end"   =>  "(if a (block xx) (block yy))"
+        "if true; x ? true elseif true end"  => "(if true (block (if x true (error-t) (error-t))) (elseif true (block)))"
+        "if true; x ? true end"  => "(if true (block (if x true (error-t))))"
+        "if true; x ? true : elseif true end"  => "(if true (block (if x true (error-t))) (elseif true (block)))"
     ],
     JuliaSyntax.parse_const_local_global => [
         "global x"             =>  "(global x)"