From f2de186ea62b22c16d38424db89c0e90d3fe75f5 Mon Sep 17 00:00:00 2001
From: Alex Semin <alllexsm@gmail.com>
Date: Tue, 19 Dec 2023 11:32:34 +0100
Subject: [PATCH] Fix `separated` and `split` combinator implementations

---
 .../kotlin/me/alllex/parsus/parser/parsers.kt |  6 ++---
 .../kotlin/me/alllex/parsus/Tests.kt          | 23 +++++++++++++++++++
 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/src/commonMain/kotlin/me/alllex/parsus/parser/parsers.kt b/src/commonMain/kotlin/me/alllex/parsus/parser/parsers.kt
index 1df053c..fe39c64 100644
--- a/src/commonMain/kotlin/me/alllex/parsus/parser/parsers.kt
+++ b/src/commonMain/kotlin/me/alllex/parsus/parser/parsers.kt
@@ -68,9 +68,9 @@ suspend fun <T : Any> ParsingScope.split(
 
     val values = mutableListOf<T>()
     values += if (!allowEmpty) term() else poll(term) ?: return emptyList()
-    while (true) {
-        poll(separator) ?: break
-        values += if (!trailingSeparator) term() else (poll(term) ?: break)
+    values += repeat(ignored(separator) * term, atLeast = 0)
+    if (trailingSeparator) {
+        poll(separator)
     }
     return values
 }
diff --git a/src/commonTest/kotlin/me/alllex/parsus/Tests.kt b/src/commonTest/kotlin/me/alllex/parsus/Tests.kt
index fdfd52e..8738125 100644
--- a/src/commonTest/kotlin/me/alllex/parsus/Tests.kt
+++ b/src/commonTest/kotlin/me/alllex/parsus/Tests.kt
@@ -435,6 +435,29 @@ class Tests {
             assertParsed("a,a").isEqualTo(node(a.lex(0), a.lex(2)))
             assertParsed("a,a,").isEqualTo(node(a.lex(0), a.lex(2)))
         }
+
+        object : Grammar<SyntaxTree>() {
+            val com by literalToken(",")
+            val a by literalToken("a")
+            val b by literalToken("b")
+            val ap by parser { lexeme(a) }
+            val bp by parser { lexeme(b) }
+            override val root by separated(ap, com) * -com * bp map { (a, b) -> node(a + b) }
+        }.run {
+            assertParsed("a,b").isEqualTo(node(a.lex(0), b.lex(2)))
+            assertParsed("a,a,b").isEqualTo(node(a.lex(0), a.lex(2), b.lex(4)))
+        }
+
+        object : Grammar<SyntaxTree>() {
+            val com by literalToken(",")
+            val a by literalToken("a")
+            val b by literalToken("b")
+            val ap by parser { lexeme(a) }
+            val bp by parser { lexeme(b) }
+            override val root by separated(ap, com, trailingSeparator = true) * -com * bp map { (a, b) -> node(a + b) }
+        }.run {
+            assertParsed("a,,b").isEqualTo(node(a.lex(0), b.lex(3)))
+        }
     }
 
 }