From 5511115cf8a5283c9ea6b3433998cf23da8a19b5 Mon Sep 17 00:00:00 2001
From: BENJAMIN PEINHARDT <benjaminpeinhardt@gmail.com>
Date: Fri, 29 Dec 2023 18:04:10 -0600
Subject: [PATCH] to_lists_or_error

---
 CHANGELOG.md        |  3 +++
 README.md           |  8 --------
 gleam.toml          |  2 +-
 src/gsv.gleam       | 14 ++++++++++++++
 test/gsv_test.gleam |  9 +++++++++
 5 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1647500..a3fbdd1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 ## Unreleased
 
+## v1.2.0 - 29 December 2023
+- Add `to_lists_or_error` function
+
 ## v1.1.0 - 29 December 2023
 - Add a function which panics with an appropriate error message on failure to 
   parse csv. This includes the token location.
diff --git a/README.md b/README.md
index f9e1f0e..23bf0fe 100644
--- a/README.md
+++ b/README.md
@@ -26,14 +26,6 @@ pub fn main() {
 }
 ```
 
-## Quick start
-
-```sh
-gleam run   # Run the project
-gleam test  # Run the tests
-gleam shell # Run an Erlang shell
-```
-
 ## Installation
 
 If available on Hex this package can be added to your Gleam project:
diff --git a/gleam.toml b/gleam.toml
index d22784b..b12ae8f 100644
--- a/gleam.toml
+++ b/gleam.toml
@@ -1,5 +1,5 @@
 name = "gsv"
-version = "1.1.0"
+version = "1.2.0"
 gleam = ">= 0.32.0"
 description = "A simple csv parser and generator written in gleam "
 
diff --git a/src/gsv.gleam b/src/gsv.gleam
index b8555c8..1e1ce51 100644
--- a/src/gsv.gleam
+++ b/src/gsv.gleam
@@ -38,6 +38,20 @@ pub fn to_lists_or_panic(input: String) -> List(List(String)) {
   }
 }
 
+/// Parses a csv string to a list of lists of strings.
+/// Automatically handles Windows and Unix line endings.
+/// Returns a string error msg if the string is not valid csv.
+pub fn to_lists_or_error(input: String) -> Result(List(List(String)), String) {
+  input
+  |> token.scan
+  |> token.with_location
+  |> ast.parse
+  |> result.map_error(fn(e) {
+    let ParseError(Location(line, column), msg) = e
+    "[" <> "line " <> int.to_string(line) <> " column " <> int.to_string(column) <> "] of csv: " <> msg
+  })
+}
+
 /// Option for using "\n = LF = Unix" or "\r\n = CRLF = Windows"
 /// line endings. Use with the `from_lists` function when 
 /// writing to a csv string.
diff --git a/test/gsv_test.gleam b/test/gsv_test.gleam
index 4b6b326..0b04f7f 100644
--- a/test/gsv_test.gleam
+++ b/test/gsv_test.gleam
@@ -170,6 +170,15 @@ pub fn error_cases_test() {
     "Expected escaped or non-escaped string after comma, found: ,",
   ))
 }
+
 // pub fn totally_panics_test() {
 //   "Ben, 25,, TRUE" |> gsv.to_lists_or_panic
 // }
+
+pub fn totally_errors_test() {
+  "Ben, 25,, TRUE"
+  |> gsv.to_lists_or_error
+  |> should.equal(Error(
+    "[line 1 column 9] of csv: Expected escaped or non-escaped string after comma, found: ,",
+  ))
+}