fix ellipsis tail from SRFI-46 #43

jcubic · Aug 22, 2020 · 844723a · 844723a
1 parent b66acbb
commit 844723a
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Showing 5 changed files with 51 additions and 13 deletions.
diff --git a/README.md b/README.md
@@ -1,7 +1,7 @@
 ![LIPS - Scheme Based Powerful Lisp Language](https://github.com/jcubic/lips/blob/devel/assets/lips.svg?raw=true)
 
 [![npm](https://img.shields.io/badge/npm-1.0.0%E2%80%93beta.3-blue.svg)](https://www.npmjs.com/package/@jcubic/lips)
-[![travis](https://travis-ci.org/jcubic/lips.svg?branch=devel&f2a5a5623bf3a3610ae946274aeaa01cfd91754e)](https://travis-ci.org/jcubic/lips)
+[![travis](https://travis-ci.org/jcubic/lips.svg?branch=devel&b66acbb057dad33253820b9e649039581579dc31)](https://travis-ci.org/jcubic/lips)
 [![Coverage Status](https://coveralls.io/repos/github/jcubic/lips/badge.svg?branch=devel&2c48907438a7265935a7b21e6931008d)](https://coveralls.io/github/jcubic/lips?branch=devel)
 [![Join Gitter Chat](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/jcubic/lips)
 

diff --git a/dist/lips.js b/dist/lips.js
@@ -31,7 +31,7 @@
  * Copyright (c) 2014-present, Facebook, Inc.
  * released under MIT license
  *
- * build: Sat, 22 Aug 2020 14:06:34 +0000
+ * build: Sat, 22 Aug 2020 16:08:48 +0000
  */
 (function () {
   'use strict';
@@ -3886,9 +3886,26 @@
         }
 
         if (pattern instanceof Pair && pattern.cdr instanceof Pair && LSymbol.is(pattern.cdr.car, ellipsis_symbol)) {
-          // pattern (... ???)
+          // pattern (... ???) - SRFI-46
           if (pattern.cdr.cdr !== nil) {
-            throw new Error('syntax: invalid usage of ellipsis');
+            if (pattern.cdr.cdr instanceof Pair) {
+              // if we have (x ... a b) we need to remove two from the end
+              var list_len = pattern.cdr.cdr.length();
+              var code_len = code.length();
+              var list = code;
+
+              while (code_len - 1 > list_len) {
+                list = list.cdr;
+                code_len--;
+              }
+
+              var rest = list.cdr;
+              list.cdr = nil;
+
+              if (!traverse(pattern.cdr.cdr, rest, pattern_names, ellipsis)) {
+                return false;
+              }
+            }
           }
 
           if (pattern.car instanceof LSymbol) {
@@ -10271,10 +10288,10 @@
 
     var banner = function () {
       // Rollup tree-shaking is removing the variable if it's normal string because
-      // obviously 'Sat, 22 Aug 2020 14:06:34 +0000' == '{{' + 'DATE}}'; can be removed
+      // obviously 'Sat, 22 Aug 2020 16:08:48 +0000' == '{{' + 'DATE}}'; can be removed
       // but disablig Tree-shaking is adding lot of not used code so we use this
       // hack instead
-      var date = LString('Sat, 22 Aug 2020 14:06:34 +0000').valueOf();
+      var date = LString('Sat, 22 Aug 2020 16:08:48 +0000').valueOf();
 
       var _date = date === '{{' + 'DATE}}' ? new Date() : new Date(date);
 
@@ -10311,7 +10328,7 @@
     var lips = {
       version: 'DEV',
       banner: banner,
-      date: 'Sat, 22 Aug 2020 14:06:34 +0000',
+      date: 'Sat, 22 Aug 2020 16:08:48 +0000',
       exec: exec,
       parse: parse,
       tokenize: tokenize,

diff --git a/dist/lips.min.js b/dist/lips.min.js
diff --git a/src/lips.js b/src/lips.js
@@ -2330,9 +2330,23 @@
             if (pattern instanceof Pair &&
                 pattern.cdr instanceof Pair &&
                 LSymbol.is(pattern.cdr.car, ellipsis_symbol)) {
-                // pattern (... ???)
+                // pattern (... ???) - SRFI-46
                 if (pattern.cdr.cdr !== nil) {
-                    throw new Error('syntax: invalid usage of ellipsis');
+                    if (pattern.cdr.cdr instanceof Pair) {
+                        // if we have (x ... a b) we need to remove two from the end
+                        const list_len = pattern.cdr.cdr.length();
+                        let code_len = code.length();
+                        let list = code;
+                        while (code_len - 1 > list_len) {
+                            list = list.cdr;
+                            code_len--;
+                        }
+                        const rest = list.cdr;
+                        list.cdr = nil;
+                        if (!traverse(pattern.cdr.cdr, rest, pattern_names, ellipsis)) {
+                            return false;
+                        }
+                    }
                 }
                 if (pattern.car instanceof LSymbol) {
                     let name = pattern.car.name;

diff --git a/tests/syntax.scm b/tests/syntax.scm
@@ -360,7 +360,7 @@
                         (f :::)))
         (t.is result '((1) 2 (3) (4)))))
 
-(test_ "syntax-rules: elipsis in middle of pattern (srfi-46)"
+(test "syntax-rules: tail of ellipsis (srfi-46)"
       (lambda (t)
 
         (define result (let-syntax
@@ -369,8 +369,15 @@
                                    (list ?x (list ?y ...) ?z)))))
                         (foo 1 2 3 4 5)))
 
-        (t.is result '(1 (2 3 4) 5))))
+        (t.is result '(1 (2 3 4) 5))
 
+        (define result (let-syntax
+                          ((foo (syntax-rules ()
+                                  ((foo ?a ?b ... ?c ?d)
+                                   (list ?a (list ?b ...) ?c ?d)))))
+                        (foo 1 2 3 4 5)))
+
+        (t.is result '(1 (2 3) 4 5))))
 
 (test "syntax-rules: rec macro (srfi-31)"
       (lambda (t)