From c720cc00e36547da1db7c8e15082dcfb734c7c56 Mon Sep 17 00:00:00 2001
From: Jonathan Turner <jonathan.d.turner@gmail.com>
Date: Tue, 24 Sep 2019 08:24:51 +1200
Subject: [PATCH] More 'did you mean?' errors

---
 src/errors.rs             | 18 ------------------
 src/evaluate/evaluator.rs | 20 +++++++++++++++-----
 2 files changed, 15 insertions(+), 23 deletions(-)

diff --git a/src/errors.rs b/src/errors.rs
index db70e13548..7e9c14b239 100644
--- a/src/errors.rs
+++ b/src/errors.rs
@@ -12,20 +12,6 @@ pub enum Description {
     Synthetic(String),
 }
 
-impl Description {
-    pub fn from(value: Tagged<impl Into<String>>) -> Description {
-        let value_tag = value.tag();
-
-        match value_tag {
-            Tag {
-                span: crate::data::meta::Span { start: 0, end: 0 },
-                ..
-            } => Description::Synthetic(value.item.into()),
-            _ => Description::Source(Tagged::from_item(value.item.into(), value_tag)),
-        }
-    }
-}
-
 impl Description {
     fn into_label(self) -> Result<Label<Tag>, String> {
         match self {
@@ -114,10 +100,6 @@ impl ShellError {
         .start()
     }
 
-    pub(crate) fn missing_property(subpath: Description, expr: Description) -> ShellError {
-        ProximateShellError::MissingProperty { subpath, expr }.start()
-    }
-
     pub(crate) fn missing_value(tag: Option<Tag>, reason: impl Into<String>) -> ShellError {
         ProximateShellError::MissingValue {
             tag,
diff --git a/src/evaluate/evaluator.rs b/src/evaluate/evaluator.rs
index 8228c1035c..a111d3964d 100644
--- a/src/evaluate/evaluator.rs
+++ b/src/evaluate/evaluator.rs
@@ -1,5 +1,5 @@
 use crate::data::base::Block;
-use crate::errors::{ArgumentError, Description};
+use crate::errors::ArgumentError;
 use crate::parser::{
     hir::{self, Expression, RawExpression},
     CommandRegistry, Text,
@@ -87,10 +87,20 @@ pub(crate) fn evaluate_baseline_expr(
 
                 match next {
                     None => {
-                        return Err(ShellError::missing_property(
-                            Description::from(item.tagged_type_name()),
-                            Description::from(name.clone()),
-                        ))
+                        let possibilities = item.data_descriptors();
+
+                        let mut possible_matches: Vec<_> = possibilities
+                            .iter()
+                            .map(|x| (natural::distance::levenshtein_distance(x, &name), x))
+                            .collect();
+
+                        possible_matches.sort();
+
+                        return Err(ShellError::labeled_error(
+                            "Unknown column",
+                            format!("did you mean '{}'?", possible_matches[0].1),
+                            expr.tag(),
+                        ));
                     }
                     Some(next) => {
                         item = next.clone().item.tagged(expr.tag());