Changes between Version 6 and Version 7 of Taskforces/FCS/FCS-QL

Timestamp:

08/05/15 12:47:21 (9 years ago)

Author:

peter.beinema@mpi.nl

Comment:

--

Taskforces/FCS/FCS-QL

@@ -110 +110 @@
 == Discussion ==
 Peter Beinema, MPI, proposes some minor changes to the grammar:
- * main query [2] / simple query [3]: above definition generate structural ambiguity. Not a problem for ANTLR (which selects the right-recursive solution), but some other parser generators generate all solutions - which are exponential wrt the number of main queries. I propose to use the alternative rules given below.
- * above rule [2] can generate infinite array of quantifiers: "word" +*{23}(,17}? would be legal.
- * rule 5: option marker '?' makes "[]" a valid query. Propose to remove question mark.
- * expression [11] / basic expression [12]: structural ambiguity. See proposed alternative below.
+ * main query {{{[2]}}} / simple query {{{[3]}}}: above definition generate structural ambiguity. Not a problem for ANTLR (which selects the right-recursive solution), but some other parser generators generate all solutions - which are exponential wrt the number of main queries. I propose to use the alternative rules given below.
+ * above rule {{{[2]}}} can generate infinite array of quantifiers: {{{"word" +*{23}{,17}{2,}?+}}} would be legal.
+ * rule {{{[5]}}}: option marker '?' makes "[]" a valid query. Propose to remove question mark.
+ * expression {{{11}}} / basic expression {{{[12]}}}: structural ambiguity. See proposed alternative below.
+ * attached file contains an antlr4 grammar, including comments on how to use it on mac / unix / linux platform
 == ENBF ==
 {{{
@@ -124 +125 @@
 
 [3 v2]
-
 simple_query ::=
       '(' main_query ')'  /* embedding moved from main-query to simple-query
@@ -144 +144 @@
       '(' expression ')'        // grouping
     | '!' expression            // not
-    | attribute operator flagged_regexp
-
+    | attribute operator flagged-regexp
 }}}