Fix degenerate case of case with a single when and an else

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 **NOTE:** In order to *build* lexpjs with Unicode-friendly identifiers enabled (if, for some reason, the included pre-built `lexp.js` file doesn't suit your needs), you first need to modify *jison-lex* to allow Unicode property escapes in its *RegExp*s. See `README-lexer.md` for details.
 
+## 1.0.23321
+
+* Fix degenerate case of `case` statement with a single `when` and an `else` (which is really an `if` made complex).
+
 ## 1.0.23297
 
 * Add `range()` function with more flexibility than short-cut range operator (`..`).

grammar.jison

@@ -175,7 +175,7 @@
 %start expressions
 
 %{
-    /* Grammar 23296 */
+    /* Grammar 23321 */
 
     var buffer = "", qsep = "";
 
@@ -309,6 +309,8 @@ when_list
         { $1.expr.push( atom( 'if', { test: $3, tc: $5, fc: $7, locs: [@3, @5, @7] } ) ); $$ = $1; }
     | when_list WHEN e COLON e
         { $1.expr.push( atom( 'if', { test: $3, tc: $5, locs: [@3, @5] } ) ); $$ = $1; }
+    | WHEN e COLON e ELSE e
+        { $$ = atom( 'list', { expr: [ atom( 'if', { test: $2, tc: $4, fc: $6, locs: [@2, @4, @5] } ) ] } ); }
     | WHEN e COLON e
         { $$ = atom( 'list', { expr: [ atom( 'if', { test: $2, tc: $4, locs: [@2, @4] } ) ] } ); }
     ;

package.json

@@ -1,6 +1,6 @@
 {
   "name": "lexpjs",
-  "version": "1.0.23297",
+  "version": "1.0.23321",
   "description": "An expression parser written in JavaScript",
   "main": "cli.js",
   "scripts": {

test.js

@@ -1,4 +1,4 @@
-const version = 23297;
+const version = 23321;
 
 const verbose = false;  // If true, all tests and results printed; otherwise just errors.
 
@@ -420,7 +420,8 @@ var test_expr = [
     , { expr: 't=12, case when t==1: "one" when t==2: "two" when t==12: "twelve" end', expect: "twelve" }
     , { expr: 't=9, case when t==1: "one" when t==2: "two" when t==12: "twelve" end', expect: null }
     , { expr: 't=11, case when t==1: "one" when t==2: "two" when t==12: "twelve" else "unknown" end', expect: "unknown" }
-
+    , { expr: 'case when t==1: "one" end', expect: null }  // abbreviated syntax (nonsense, use 'if', but supported)
+    , { expr: 'case when t==1: "one" else "two" end', expect: "two" }  // abbreviated syntax (nonsense, use 'if', but supported)
 
     /* Iteration */
     , { expr: "each item in [1,2,3,4,5]: 2*item", expect: [ 2,4,6,8,10 ] }

umd-preamble.js

@@ -18,7 +18,7 @@
  *  SOFTWARE.
  */
 
-const version = 23297;
+const version = 23321;
 
 const FEATURE_MONTH_BASE = 1;   /* 1 = months 1-12; set to 0 if you prefer JS semantics where 0=Jan,11=Dec */
 const MAX_RANGE = 1000;         /* Maximum number of elements in a result range op result array */