From e102be835f08b328bc63c5d33cdecb563cf8a29a Mon Sep 17 00:00:00 2001
From: Jonas Wanke <contact@jonas-wanke.com>
Date: Thu, 14 Dec 2023 18:50:10 +0100
Subject: [PATCH 01/13] Export checkEquals

---
 packages/Core/_.candy | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/Core/_.candy b/packages/Core/_.candy
index ad7a60ac0..5719f5d21 100644
--- a/packages/Core/_.candy
+++ b/packages/Core/_.candy
@@ -1,5 +1,5 @@
 bool := use ".bool"
-[check] := use ".check"
+[check, checkEquals] := use ".check"
 [if, ifElse, loop, recursive, repeat] := use ".controlFlow"
 [equals] := use ".equality"
 fixedDecimal := use ".fixedDecimal"

From 09cd664c9ecdfa437574c086c8b2a7d95ab054bc Mon Sep 17 00:00:00 2001
From: Jonas Wanke <contact@jonas-wanke.com>
Date: Thu, 14 Dec 2023 18:50:23 +0100
Subject: [PATCH 02/13] Add iterable.joinToTextWithSeparator

---
 packages/Core/iterable.candy | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/packages/Core/iterable.candy b/packages/Core/iterable.candy
index 63bca3d01..122185672 100644
--- a/packages/Core/iterable.candy
+++ b/packages/Core/iterable.candy
@@ -142,6 +142,16 @@ joinToText iterable :=
     needs (text.is item)
     result | text.concatenate item
   }
+joinToTextWithSeparator iterable separator :=
+  needs (is iterable)
+  needs (text.is separator)
+
+  iterable | reduceLeft { a b ->
+    needs (text.is a)
+    needs (text.is b)
+    a | text.concatenate separator | text.concatenate b
+  }
+  | result.unwrapOr ""
 
 ## Filtering
 

From 6d08d349a76e84b8881775fe0238a53f2855e8c1 Mon Sep 17 00:00:00 2001
From: Jonas Wanke <contact@jonas-wanke.com>
Date: Thu, 14 Dec 2023 18:50:36 +0100
Subject: [PATCH 03/13] Add CSV encoder

---
 packages/Csv/_.candy        |  1 +
 packages/Csv/_package.candy |  0
 packages/Csv/encode.candy   | 47 +++++++++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+)
 create mode 100644 packages/Csv/_.candy
 create mode 100644 packages/Csv/_package.candy
 create mode 100644 packages/Csv/encode.candy

diff --git a/packages/Csv/_.candy b/packages/Csv/_.candy
new file mode 100644
index 000000000..f3d73bac6
--- /dev/null
+++ b/packages/Csv/_.candy
@@ -0,0 +1 @@
+[encode] := use ".encode"
diff --git a/packages/Csv/_package.candy b/packages/Csv/_package.candy
new file mode 100644
index 000000000..e69de29bb
diff --git a/packages/Csv/encode.candy b/packages/Csv/encode.candy
new file mode 100644
index 000000000..3f3539664
--- /dev/null
+++ b/packages/Csv/encode.candy
@@ -0,0 +1,47 @@
+[bool, checkEquals, equals, ifElse, iterable, list, result, text] = use "Core"
+
+encodeField field =
+  needs (text.is field)
+  ifElse
+    field | text.contains '"""' | bool.lazyOr { field | text.contains text.newline }
+    {
+      encoded = field | text.characters | iterable.fromList
+      | iterable.map { char -> ifElse (char | equals '"""') { '""""' } { char } }
+      | iterable.joinToText
+      '""{{encoded}}""'
+    }
+    { field }
+
+encodeLine line =
+  needs (list.is line)
+  needs (line | iterable.fromList | iterable.all text.is)
+  line | iterable.fromList | iterable.map encodeField | iterable.joinToTextWithSeparator ","
+
+encode lines :=
+  needs (list.is lines)
+  needs (lines | iterable.fromList | iterable.all list.is)
+  fieldsPerLine = lines | list.first | result.map list.length | result.unwrapOr 0
+  lines | iterable.fromList | iterable.map { line ->
+    needs (line | list.length | equals fieldsPerLine)
+    "{line | encodeLine}{text.newline}"
+  }
+  | iterable.joinToText
+
+test =
+  # From https://datatracker.ietf.org/doc/html/rfc4180#section-2
+  checkEquals (encodeLine ("aaa", "bbb", "ccc")) "aaa,bbb,ccc"
+
+  checkEquals
+    encode (("aaa", "bbb", "ccc"), ("zzz", "yyy", "xxx"))
+    "aaa,bbb,ccc{text.newline}zzz,yyy,xxx{text.newline}"
+  checkEquals
+    encode (("field_name", "field_name", "field_name"), ("aaa", "bbb", "ccc"), ("zzz", "yyy", "xxx"))
+    "
+      field_name,field_name,field_name{text.newline}aaa,bbb,ccc{text.newline}zzz,yyy,xxx{text.newline}
+    "
+  checkEquals
+    encode (("aaa", "b{text.newline}bb", "ccc"), ("zzz", "yyy", "xxx"))
+    '"aaa,"b{{text.newline}}bb",ccc{{text.newline}}zzz,yyy,xxx{{text.newline}}"'
+  checkEquals (encode (("aaa", '"b"bb"', "ccc"),)) '"aaa,"b""bb",ccc{{text.newline}}"'
+
+main environment := "Abc"
\ No newline at end of file

From 4c99667e6567fbc914fc363c52696f85eb45e484 Mon Sep 17 00:00:00 2001
From: Jonas Wanke <contact@jonas-wanke.com>
Date: Thu, 18 Jan 2024 18:23:37 +0100
Subject: [PATCH 04/13] Add iterator.joinToTextWithSeparator

---
 packages/Core/iterator.candy | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/packages/Core/iterator.candy b/packages/Core/iterator.candy
index 01984db51..47ecd356f 100644
--- a/packages/Core/iterator.candy
+++ b/packages/Core/iterator.candy
@@ -174,6 +174,16 @@ joinToText iterator := iterator | wrapSafe { needs False "`joinToText` needs an
   needs (text.is item)
   result | text.concatenate item
 }
+joinToTextWithSeparator iterator separator :=
+  iterator = iterator | wrapSafe { needs False "`joinToTextWithSeparator` needs an iterator." }
+  needs (text.is separator)
+
+  iterator | reduceLeft { a b ->
+    needs (text.is a)
+    needs (text.is b)
+    a | text.concatenate separator | text.concatenate b
+  }
+  | result.unwrapOr ""
 
 ## Filtering
 

From 34aa7b384bf8284858ad53b9deee37c2fae5310d Mon Sep 17 00:00:00 2001
From: Jonas Wanke <contact@jonas-wanke.com>
Date: Thu, 18 Jan 2024 18:37:42 +0100
Subject: [PATCH 05/13] Update CSV encoder to iterator (vs. iterable)

---
 packages/Csv/encode.candy | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/packages/Csv/encode.candy b/packages/Csv/encode.candy
index 3f3539664..1f0bfb809 100644
--- a/packages/Csv/encode.candy
+++ b/packages/Csv/encode.candy
@@ -1,31 +1,31 @@
-[bool, checkEquals, equals, ifElse, iterable, list, result, text] = use "Core"
+[bool, checkEquals, equals, ifElse, iterator, list, result, text] = use "Core"
 
 encodeField field =
   needs (text.is field)
   ifElse
     field | text.contains '"""' | bool.lazyOr { field | text.contains text.newline }
     {
-      encoded = field | text.characters | iterable.fromList
-      | iterable.map { char -> ifElse (char | equals '"""') { '""""' } { char } }
-      | iterable.joinToText
+      encoded = field | text.characters | iterator.fromList
+      | iterator.map { char -> ifElse (char | equals '"""') { '""""' } { char } }
+      | iterator.joinToText
       '""{{encoded}}""'
     }
     { field }
 
 encodeLine line =
   needs (list.is line)
-  needs (line | iterable.fromList | iterable.all text.is)
-  line | iterable.fromList | iterable.map encodeField | iterable.joinToTextWithSeparator ","
+  needs (line | iterator.fromList | iterator.all text.is)
+  line | iterator.fromList | iterator.map encodeField | iterator.joinToTextWithSeparator ","
 
 encode lines :=
   needs (list.is lines)
-  needs (lines | iterable.fromList | iterable.all list.is)
+  needs (lines | iterator.fromList | iterator.all list.is)
   fieldsPerLine = lines | list.first | result.map list.length | result.unwrapOr 0
-  lines | iterable.fromList | iterable.map { line ->
+  lines | iterator.fromList | iterator.map { line ->
     needs (line | list.length | equals fieldsPerLine)
     "{line | encodeLine}{text.newline}"
   }
-  | iterable.joinToText
+  | iterator.joinToText
 
 test =
   # From https://datatracker.ietf.org/doc/html/rfc4180#section-2

From 734b4b5b2a88388a61d84de36f6d813f44b6e3c5 Mon Sep 17 00:00:00 2001
From: Jonas Wanke <contact@jonas-wanke.com>
Date: Thu, 18 Jan 2024 18:37:56 +0100
Subject: [PATCH 06/13] Remove CSV encoder's main function

---
 packages/Csv/encode.candy | 2 --
 1 file changed, 2 deletions(-)

diff --git a/packages/Csv/encode.candy b/packages/Csv/encode.candy
index 1f0bfb809..9b418caf3 100644
--- a/packages/Csv/encode.candy
+++ b/packages/Csv/encode.candy
@@ -43,5 +43,3 @@ test =
     encode (("aaa", "b{text.newline}bb", "ccc"), ("zzz", "yyy", "xxx"))
     '"aaa,"b{{text.newline}}bb",ccc{{text.newline}}zzz,yyy,xxx{{text.newline}}"'
   checkEquals (encode (("aaa", '"b"bb"', "ccc"),)) '"aaa,"b""bb",ccc{{text.newline}}"'
-
-main environment := "Abc"
\ No newline at end of file

From 3d8a2aaecdd80e359b562ed35b9706cdd8a9e01d Mon Sep 17 00:00:00 2001
From: Jonas Wanke <contact@jonas-wanke.com>
Date: Thu, 18 Jan 2024 18:44:38 +0100
Subject: [PATCH 07/13] Set CSV package label automatically

---
 .github/labels.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/.github/labels.yaml b/.github/labels.yaml
index deb49ebc1..598d43f32 100644
--- a/.github/labels.yaml
+++ b/.github/labels.yaml
@@ -20,6 +20,8 @@
   - vscode_extension/**/*
 'P: Core':
   - packages/Core/**/*
+'P: Csv':
+  - packages/Csv/**/*
 'P: Examples':
   - packages/Examples/**/*
 'P: Http':

From 90113459f2b8eaee1c02beb6be72fa5eb94062a9 Mon Sep 17 00:00:00 2001
From: Jonas Wanke <contact@jonas-wanke.com>
Date: Thu, 18 Jan 2024 22:10:46 +0100
Subject: [PATCH 08/13] Add Parser package

---
 .github/labels.yaml            |  2 ++
 packages/Parser/_.candy        |  2 ++
 packages/Parser/_package.candy |  0
 packages/Parser/cursor.candy   | 25 ++++++++++++++++++
 packages/Parser/parser.candy   | 48 ++++++++++++++++++++++++++++++++++
 5 files changed, 77 insertions(+)
 create mode 100644 packages/Parser/_.candy
 create mode 100644 packages/Parser/_package.candy
 create mode 100644 packages/Parser/cursor.candy
 create mode 100644 packages/Parser/parser.candy

diff --git a/.github/labels.yaml b/.github/labels.yaml
index 598d43f32..62389dc93 100644
--- a/.github/labels.yaml
+++ b/.github/labels.yaml
@@ -26,6 +26,8 @@
   - packages/Examples/**/*
 'P: Http':
   - packages/Http/**/*
+'P: Parser':
+  - packages/Parser/**/*
 'P: ProgrammingLanguageBenchmarks':
   - packages/ProgrammingLanguageBenchmarks/**/*
 'P: Random':
diff --git a/packages/Parser/_.candy b/packages/Parser/_.candy
new file mode 100644
index 000000000..f58aec955
--- /dev/null
+++ b/packages/Parser/_.candy
@@ -0,0 +1,2 @@
+cursor := use ".cursor"
+parser := use ".parser"
diff --git a/packages/Parser/_package.candy b/packages/Parser/_package.candy
new file mode 100644
index 000000000..e69de29bb
diff --git a/packages/Parser/cursor.candy b/packages/Parser/cursor.candy
new file mode 100644
index 000000000..416dd549f
--- /dev/null
+++ b/packages/Parser/cursor.candy
@@ -0,0 +1,25 @@
+[bool, equals, int, text] = use "Core"
+
+is cursor := cursor %
+  Cursor [source, offset] ->
+    text.is source | bool.lazyAnd { int.is offset } | bool.lazyAnd { int.isNonNegative offset }
+    | bool.lazyAnd { offset | int.isLessThanOrEqualTo (source | text.length) }
+  _ -> False
+
+newAtStart source :=
+  needs (text.is source)
+  Cursor [source, Offset: 0]
+
+isAtEnd cursor :=
+  needs (is cursor)
+  Cursor [source, offset] = cursor
+  offset | equals (source | text.length)
+
+add cursor length :=
+  needs (is cursor)
+  needs (int.is length)
+  needs (int.isNonNegative length)
+  Cursor [source, offset] = cursor
+  offset = offset | int.add length
+  needs (offset | int.isLessThanOrEqualTo (source | text.length))
+  Cursor [source, offset]
diff --git a/packages/Parser/parser.candy b/packages/Parser/parser.candy
new file mode 100644
index 000000000..d550d4d7a
--- /dev/null
+++ b/packages/Parser/parser.candy
@@ -0,0 +1,48 @@
+[bool, equals, ifElse, int, text] = use "Core"
+cursor = use "..cursor"
+
+is parser := parser %
+  Parser c -> cursor.is c
+  _ -> False
+
+new source :=
+  needs (text.is source)
+  Parser (cursor.newAtStart source)
+
+peek parser :=
+  needs (is parser)
+  Parser c = parser
+  ifElse (c | cursor.isAtEnd) { Error Empty } {
+    Cursor [source, offset] = c
+    Ok (source | text.getRange offset (offset | int.add 1))
+  }
+next parser :=
+  needs (is parser)
+  Parser c = parser
+  ifElse (c | cursor.isAtEnd) { Error Empty } {
+    Cursor [source, offset] = c
+    c = c | cursor.add 1
+    Cursor [Offset: newOffset] = c
+    Ok [Parser: Parser c, Character: source | text.getRange offset newOffset]
+  }
+
+matches parser expectedText :=
+  needs (is parser)
+  needs (text.is expectedText)
+  Parser (Cursor [source, offset]) = parser
+  endExclusive = offset | int.add (expectedText | text.length)
+  endExclusive | int.isLessThanOrEqualTo (source | text.length)
+  | bool.lazyAnd { source | text.getRange offset endExclusive | equals expectedText }
+require parser expectedText :=
+  needs (is parser)
+  needs (text.is expectedText)
+  ifElse
+    parser | matches expectedText
+    {
+      Parser c = parser
+      Ok (Parser (c | cursor.add (expectedText | text.length)))
+    }
+    {
+      Parser (Cursor [offset]) = parser
+      Error '"Expected "{{expectedText}}" at offset {offset}."'
+    }

From a042ecded9ce31a93e93c29f7d43655d9f70e2de Mon Sep 17 00:00:00 2001
From: Jonas Wanke <contact@jonas-wanke.com>
Date: Thu, 18 Jan 2024 22:11:09 +0100
Subject: [PATCH 09/13] Add CSV decoder

---
 packages/Core/list.candy  |  4 +--
 packages/Csv/_.candy      |  1 +
 packages/Csv/decode.candy | 55 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 58 insertions(+), 2 deletions(-)
 create mode 100644 packages/Csv/decode.candy

diff --git a/packages/Core/list.candy b/packages/Core/list.candy
index a08562e7a..301516bc9 100644
--- a/packages/Core/list.candy
+++ b/packages/Core/list.candy
@@ -12,7 +12,7 @@ is value := type.is value List
 length := builtins.listLength
 isEmpty list :=
   needs (is list)
-  equals (length list) 0
+  equals (list | length) 0
 
 lastIndex list :=
   needs (is list)
@@ -55,7 +55,7 @@ prepend list item :=
   list | insert 0 item
 append list item :=
   needs (is list)
-  list | insert (length list) item
+  list | insert (list | length) item
 
 replace := builtins.listReplace
 update list index updater :=
diff --git a/packages/Csv/_.candy b/packages/Csv/_.candy
index f3d73bac6..ae2e4492a 100644
--- a/packages/Csv/_.candy
+++ b/packages/Csv/_.candy
@@ -1 +1,2 @@
+[decode] := use ".decode"
 [encode] := use ".encode"
diff --git a/packages/Csv/decode.candy b/packages/Csv/decode.candy
new file mode 100644
index 000000000..378be905c
--- /dev/null
+++ b/packages/Csv/decode.candy
@@ -0,0 +1,55 @@
+[bool, checkEquals, ifElse, int, list, recursive, text] = use "Core"
+[parser] = use "Parser"
+
+decodeFile csv :=
+  needs (text.is csv)
+  recursive [Lines: (,), Fields: (,), FieldStartOffset: 0, P: parser.new csv] {
+    recurse [lines, fields, fieldStartOffset, p] ->
+    Parser (Cursor [source, Offset: oldOffset]) = p
+    p | parser.next %
+      Ok [Parser: p, character] ->
+        Parser (Cursor [Offset: newOffset]) = p
+        character %
+          "," ->
+            recurse [
+              lines,
+              Fields: fields | list.append (source | text.getRange fieldStartOffset oldOffset),
+              FieldStartOffset: newOffset,
+              p,
+            ]
+          "
+            
+          
+          " ->
+            fields = fields | list.append (source | text.getRange fieldStartOffset oldOffset)
+            recurse [Lines: lines | list.append fields, Fields: (,), FieldStartOffset: newOffset, p]
+          # TODO(JonasWanke): handle quoted field
+          _ -> recurse [lines, fields, fieldStartOffset, p]
+      Error Empty ->
+        finalField = source | text.getRange fieldStartOffset oldOffset
+        Ok
+          ifElse
+            finalField | text.isEmpty | bool.lazyAnd { fields | list.isEmpty }
+            { lines }
+            { lines | list.append (fields | list.append finalField) }
+  }
+
+test =
+  # From https://datatracker.ietf.org/doc/html/rfc4180#section-2
+  checkEquals
+    decodeFile "aaa,bbb,ccc"
+    Ok (("aaa", "bbb", "ccc"),)
+
+  checkEquals
+    decodeFile "aaa,bbb,ccc{text.newline}zzz,yyy,xxx{text.newline}"
+    Ok (("aaa", "bbb", "ccc"), ("zzz", "yyy", "xxx"))
+  checkEquals
+    decodeFile "
+      field_name,field_name,field_name{text.newline}aaa,bbb,ccc{text.newline}zzz,yyy,xxx{text.newline}
+    "
+    Ok (("field_name", "field_name", "field_name"), ("aaa", "bbb", "ccc"), ("zzz", "yyy", "xxx"))
+  # TODO(JonasWanke): handle quoted field
+  # checkEquals
+  #   decodeFile '"aaa,"b{{text.newline}}bb",ccc{{text.newline}}zzz,yyy,xxx{{text.newline}}"'
+  #   Ok (("aaa", "b{text.newline}bb", "ccc"), ("zzz", "yyy", "xxx"))
+  # checkEquals (decodeFile '"aaa,"b""bb",ccc{{text.newline}}"') (Ok (("aaa", '"b"bb"', "ccc"),))

From 3721b20c0af0684c5e18e9e746f61d544b543566 Mon Sep 17 00:00:00 2001
From: Jonas Wanke <contact@jonas-wanke.com>
Date: Thu, 18 Jan 2024 22:34:00 +0100
Subject: [PATCH 10/13] Enable automerge only for PRs to main

---
 .github/workflows/pr.yaml | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/pr.yaml b/.github/workflows/pr.yaml
index f6ba90dd6..feca1f429 100644
--- a/.github/workflows/pr.yaml
+++ b/.github/workflows/pr.yaml
@@ -28,7 +28,11 @@ jobs:
       - uses: technote-space/assign-author@v1.6.2
 
   automerge-pr:
-    if: (github.event.action == 'opened' && !github.event.pull_request.draft) || github.event.action == 'ready_for_review'
+    if: >
+      github.head_ref == 'refs/heads/main'
+      && (
+        (github.event.action == 'opened' && !github.event.pull_request.draft)
+        || github.event.action == 'ready_for_review')
     runs-on: ubuntu-latest
     permissions:
       contents: write

From 382ee108008749d26b28256a4985e5ea0edab769 Mon Sep 17 00:00:00 2001
From: Jonas Wanke <contact@jonas-wanke.com>
Date: Thu, 18 Jan 2024 22:40:42 +0100
Subject: [PATCH 11/13] Fix compiler errors after merge

---
 compiler/frontend/src/mir_optimize/call_tracing.rs |  2 +-
 compiler/frontend/src/mir_optimize/pure.rs         | 12 +++++++-----
 packages/candy.code-workspace                      |  4 ++--
 3 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/compiler/frontend/src/mir_optimize/call_tracing.rs b/compiler/frontend/src/mir_optimize/call_tracing.rs
index 2803265c3..d01b47c25 100644
--- a/compiler/frontend/src/mir_optimize/call_tracing.rs
+++ b/compiler/frontend/src/mir_optimize/call_tracing.rs
@@ -29,7 +29,7 @@ pub fn remove_unnecessary_call_tracing(
                 }
             }
             _ => {
-                if !pureness.pure_definitions().contains(id) {
+                if !pureness.pure_definitions().contains(*id) {
                     for (_, only_pure_since_then) in &mut trace_call_starts {
                         *only_pure_since_then = false;
                     }
diff --git a/compiler/frontend/src/mir_optimize/pure.rs b/compiler/frontend/src/mir_optimize/pure.rs
index e091a8158..757978eb8 100644
--- a/compiler/frontend/src/mir_optimize/pure.rs
+++ b/compiler/frontend/src/mir_optimize/pure.rs
@@ -153,7 +153,7 @@ impl PurenessInsights {
     }
 
     #[must_use]
-    pub const fn pure_definitions(&self) -> &FxHashSet<Id> {
+    pub const fn pure_definitions(&self) -> &IdSet {
         &self.pure_definitions
     }
     #[must_use]
@@ -338,9 +338,10 @@ impl PurenessInsights {
 /// case: We store a [`BitVec`] where each index corresponds to an [`Id`]
 /// because our [`Id`]s are numbered sequentially.
 #[derive(Clone, Debug, Default, Eq, PartialEq)]
-struct IdSet(BitVec);
+pub struct IdSet(BitVec);
 impl IdSet {
-    fn contains(&self, id: Id) -> bool {
+    #[must_use]
+    pub fn contains(&self, id: Id) -> bool {
         if id.to_usize() >= self.0.len() {
             false
         } else {
@@ -348,11 +349,12 @@ impl IdSet {
         }
     }
 
+    #[must_use]
     pub fn iter(&self) -> IdSetIter {
         self.into_iter()
     }
 
-    fn insert(&mut self, id: Id) {
+    pub fn insert(&mut self, id: Id) {
         let additional_length_to_reserve = (id.to_usize() + 1).saturating_sub(self.0.len());
         if additional_length_to_reserve > 0 {
             self.0
@@ -360,7 +362,7 @@ impl IdSet {
         }
         self.0.set(id.to_usize(), true);
     }
-    fn remove(&mut self, id: Id) {
+    pub fn remove(&mut self, id: Id) {
         if id.to_usize() >= self.0.len() {
             return;
         }
diff --git a/packages/candy.code-workspace b/packages/candy.code-workspace
index 82b93988c..da72918b7 100644
--- a/packages/candy.code-workspace
+++ b/packages/candy.code-workspace
@@ -22,8 +22,8 @@
       "editor.defaultFormatter": "redhat.vscode-yaml"
     },
     "editor.codeActionsOnSave": {
-      "source.fixAll": true,
-      "source.organizeImports": true
+      "source.fixAll": "explicit",
+      "source.organizeImports": "explicit"
     },
     "editor.formatOnPaste": true,
     "editor.formatOnSave": true,

From aec4db94907d1bce6c8f0a193a1a9a3c158d7463 Mon Sep 17 00:00:00 2001
From: Jonas Wanke <contact@jonas-wanke.com>
Date: Thu, 18 Jan 2024 22:44:05 +0100
Subject: [PATCH 12/13] Fix csv.decode's export

---
 packages/Csv/decode.candy | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/packages/Csv/decode.candy b/packages/Csv/decode.candy
index 378be905c..4e7a1c9d7 100644
--- a/packages/Csv/decode.candy
+++ b/packages/Csv/decode.candy
@@ -1,7 +1,7 @@
 [bool, checkEquals, ifElse, int, list, recursive, text] = use "Core"
 [parser] = use "Parser"
 
-decodeFile csv :=
+decode csv :=
   needs (text.is csv)
   recursive [Lines: (,), Fields: (,), FieldStartOffset: 0, P: parser.new csv] {
     recurse [lines, fields, fieldStartOffset, p] ->
@@ -36,20 +36,18 @@ decodeFile csv :=
 
 test =
   # From https://datatracker.ietf.org/doc/html/rfc4180#section-2
-  checkEquals
-    decodeFile "aaa,bbb,ccc"
-    Ok (("aaa", "bbb", "ccc"),)
+  checkEquals (decode "aaa,bbb,ccc") (Ok (("aaa", "bbb", "ccc"),))
 
   checkEquals
-    decodeFile "aaa,bbb,ccc{text.newline}zzz,yyy,xxx{text.newline}"
+    decode "aaa,bbb,ccc{text.newline}zzz,yyy,xxx{text.newline}"
     Ok (("aaa", "bbb", "ccc"), ("zzz", "yyy", "xxx"))
   checkEquals
-    decodeFile "
+    decode "
       field_name,field_name,field_name{text.newline}aaa,bbb,ccc{text.newline}zzz,yyy,xxx{text.newline}
     "
     Ok (("field_name", "field_name", "field_name"), ("aaa", "bbb", "ccc"), ("zzz", "yyy", "xxx"))
   # TODO(JonasWanke): handle quoted field
   # checkEquals
-  #   decodeFile '"aaa,"b{{text.newline}}bb",ccc{{text.newline}}zzz,yyy,xxx{{text.newline}}"'
+  #   decode '"aaa,"b{{text.newline}}bb",ccc{{text.newline}}zzz,yyy,xxx{{text.newline}}"'
   #   Ok (("aaa", "b{text.newline}bb", "ccc"), ("zzz", "yyy", "xxx"))
-  # checkEquals (decodeFile '"aaa,"b""bb",ccc{{text.newline}}"') (Ok (("aaa", '"b"bb"', "ccc"),))
+  # checkEquals (decode '"aaa,"b""bb",ccc{{text.newline}}"') (Ok (("aaa", '"b"bb"', "ccc"),))

From 74b5426eeb817c05c69a0d4efbd3a54abd369f30 Mon Sep 17 00:00:00 2001
From: Jonas Wanke <contact@jonas-wanke.com>
Date: Thu, 18 Jan 2024 23:27:57 +0100
Subject: [PATCH 13/13] Add more CSV test cases

---
 packages/Csv/decode.candy | 59 ++++++++++++++++++++++++++++++++++++---
 packages/Csv/encode.candy | 19 ++++++++++++-
 2 files changed, 73 insertions(+), 5 deletions(-)

diff --git a/packages/Csv/decode.candy b/packages/Csv/decode.candy
index 4e7a1c9d7..546f02539 100644
--- a/packages/Csv/decode.candy
+++ b/packages/Csv/decode.candy
@@ -1,14 +1,16 @@
-[bool, checkEquals, ifElse, int, list, recursive, text] = use "Core"
-[parser] = use "Parser"
+[bool, checkEquals, equals, ifElse, int, list, recursive, text] = use "Core"
+[cursor, parser] = use "Parser"
 
 decode csv :=
   needs (text.is csv)
+  # TODO(JonasWanke): Error on lines with different field counts
   recursive [Lines: (,), Fields: (,), FieldStartOffset: 0, P: parser.new csv] {
     recurse [lines, fields, fieldStartOffset, p] ->
     Parser (Cursor [source, Offset: oldOffset]) = p
     p | parser.next %
       Ok [Parser: p, character] ->
-        Parser (Cursor [Offset: newOffset]) = p
+        Parser c = p
+        Cursor [Offset: newOffset] = c
         character %
           "," ->
             recurse [
@@ -22,7 +24,16 @@ decode csv :=
           
           " ->
             fields = fields | list.append (source | text.getRange fieldStartOffset oldOffset)
-            recurse [Lines: lines | list.append fields, Fields: (,), FieldStartOffset: newOffset, p]
+            lines = lines | list.append fields
+            # CSV files can have a trailing newline.
+            ifElse
+              (c | cursor.isAtEnd)
+              {
+                ifElse (oldOffset | equals 0) { Ok (,) } { Ok lines }
+              }
+              {
+                recurse [lines, Fields: (,), FieldStartOffset: newOffset, p]
+              }
           # TODO(JonasWanke): handle quoted field
           _ -> recurse [lines, fields, fieldStartOffset, p]
       Error Empty ->
@@ -35,6 +46,46 @@ decode csv :=
   }
 
 test =
+  checkEquals (decode "") (Ok (,))
+  checkEquals (decode "{text.newline}") (Ok (,))
+
+  checkEquals (decode "aaa") (Ok (("aaa",),))
+  checkEquals (decode "aaa{text.newline}") (Ok (("aaa",),))
+
+  checkEquals (decode " aaa ") (Ok ((" aaa ",),))
+  checkEquals (decode " aaa {text.newline}") (Ok ((" aaa ",),))
+
+  checkEquals (decode "aaa,bbb") (Ok (("aaa", "bbb"),))
+  checkEquals (decode "aaa,bbb{text.newline}") (Ok (("aaa", "bbb"),))
+  checkEquals (decode "aaa,bbb{text.newline}ccc,ddd") (Ok (("aaa", "bbb"), ("ccc", "ddd")))
+  checkEquals
+    decode "aaa,bbb{text.newline}ccc,ddd{text.newline}"
+    Ok (("aaa", "bbb"), ("ccc", "ddd"))
+  # Parser is broken, hence this verbose formatting: https://github.com/candy-lang/candy/issues/896
+  checkEquals
+    decode "
+       aaa , bbb {text.newline} ccc , ddd {text.newline}
+    "
+    Ok (
+      (
+        "
+           aaa 
+        ",
+        "
+           bbb 
+        ",
+      ),
+      (
+        "
+           ccc 
+        ",
+        "
+           ddd 
+        ",
+      ),
+    )
+
+testRfcExamples =
   # From https://datatracker.ietf.org/doc/html/rfc4180#section-2
   checkEquals (decode "aaa,bbb,ccc") (Ok (("aaa", "bbb", "ccc"),))
 
diff --git a/packages/Csv/encode.candy b/packages/Csv/encode.candy
index 9b418caf3..9b54f278d 100644
--- a/packages/Csv/encode.candy
+++ b/packages/Csv/encode.candy
@@ -27,7 +27,24 @@ encode lines :=
   }
   | iterator.joinToText
 
-test =
+testEncodeLine =
+  # TODO(JonaWanke): Add tests cases for leading/trailing whitespace when our parser is fixed,
+  # https://github.com/candy-lang/candy/issues/896
+  checkEquals (encodeLine (,)) ""
+  checkEquals (encodeLine ("aaa",)) "aaa"
+  checkEquals (encodeLine ("aaa", "bbb")) "aaa,bbb"
+
+testEncodeLineWithSpecialCharacters =
+  checkEquals (encodeLine ('"aa"a"',)) '""aa""a""'
+  checkEquals (encodeLine ("aa{text.newline}a",)) '""aa{{text.newline}}a""'
+
+testEncode =
+  checkEquals (encode (,)) ""
+  checkEquals (encode (("aaa",),)) "aaa{text.newline}"
+  checkEquals (encode (("aaa", "bbb"),)) "aaa,bbb{text.newline}"
+  checkEquals (encode (("aaa",), ("bbb",))) "aaa{text.newline}bbb{text.newline}"
+
+testRfcExamples =
   # From https://datatracker.ietf.org/doc/html/rfc4180#section-2
   checkEquals (encodeLine ("aaa", "bbb", "ccc")) "aaa,bbb,ccc"