X-Git-Url: http://nitlanguage.org

diff --git a/src/modelbuilder_base.nit b/src/modelbuilder_base.nit
index 5986770..5cc235f 100644
--- a/src/modelbuilder_base.nit
+++ b/src/modelbuilder_base.nit
@@ -86,6 +86,7 @@ class ModelBuilder
 	#
 	# If more than one class exists, then null is silently returned.
 	# It is up to the caller to post-analysis the result and display a correct error message.
+	# The method `class_not_found` can be used to display such a message.
 	fun try_get_mclass_by_qid(qid: AQclassid, mmodule: MModule): nullable MClass
 	do
 		var name = qid.n_id.text
@@ -334,21 +335,50 @@ class ModelBuilder
 		# If everything fail, then give up with class by proposing things.
 		#
 		# TODO Give hints on formal types (param and virtual)
-		# TODO How to move this in a libified autonomous code?
+		class_not_found(qid, mmodule)
+		ntype.is_broken = true
+		return null
+	end
+
+	# Print an error and suggest hints when the class identified by `qid` in `mmodule` is not found.
+	#
+	# This just print error messages.
+	fun class_not_found(qid: AQclassid, mmodule: MModule)
+	do
+		var name = qid.n_id.text
+		var qname = qid.full_name
+
+		if bad_class_names[mmodule].has(qname) then
+			error(qid, "Error: class `{qname}` not found in module `{mmodule}`.")
+			return
+		end
+		bad_class_names[mmodule].add(qname)
 
 		var all_classes = model.get_mclasses_by_name(name)
+		var hints = new Array[String]
+
+		# Look for conflicting classes.
+		if all_classes != null then for c in all_classes do
+			if not mmodule.is_visible(c.intro_mmodule, c.visibility) then continue
+			if not qid.accept(c) then continue
+			hints.add "`{c.full_name}`"
+		end
+		if hints.length > 1 then
+			error(qid, "Error: ambiguous class name `{qname}` in module `{mmodule}`. Conflicts are between {hints.join(",", " and ")}.")
+			return
+		end
+		hints.clear
 
 		# Look for imported but invisible classes.
 		if all_classes != null then for c in all_classes do
 			if not mmodule.in_importation <= c.intro_mmodule then continue
 			if mmodule.is_visible(c.intro_mmodule, c.visibility) then continue
 			if not qid.accept(c) then continue
-			error(ntype, "Error: class `{c.full_name}` not visible in module `{mmodule}`.")
-			return null
+			error(qid, "Error: class `{c.full_name}` not visible in module `{mmodule}`.")
+			return
 		end
 
 		# Look for not imported but known classes from importable modules
-		var hints = new Array[String]
 		if all_classes != null then for c in all_classes do
 			if mmodule.in_importation <= c.intro_mmodule then continue
 			if c.intro_mmodule.in_importation <= mmodule then continue
@@ -357,33 +387,33 @@ class ModelBuilder
 			hints.add "`{c.intro_mmodule.full_name}`"
 		end
 		if hints.not_empty then
-			error(ntype, "Error: class `{name}` not found in module `{mmodule}`. Maybe import {hints.join(",", " or ")}?")
-			return null
+			error(qid, "Error: class `{qname}` not found in module `{mmodule}`. Maybe import {hints.join(",", " or ")}?")
+			return
 		end
 
 		# Look for classes with an approximative name.
-		var bestd = name.length / 2 # limit up to 50% name change
+		var bests = new BestDistance[MClass](qname.length - name.length / 2) # limit up to 50% name change
 		for c in model.mclasses do
 			if not mmodule.in_importation <= c.intro_mmodule then continue
 			if not mmodule.is_visible(c.intro_mmodule, c.visibility) then continue
-			var d = name.levenshtein_distance(c.name)
-			if d <= bestd then
-				if d < bestd then
-					hints.clear
-					bestd = d
-				end
-				hints.add "`{c.full_name}`"
-			end
+			var d = qname.levenshtein_distance(c.name)
+			bests.update(d, c)
+			d = qname.levenshtein_distance(c.full_name)
+			bests.update(d, c)
 		end
-		if hints.not_empty then
-			error(ntype, "Error: class `{name}` not found in module `{mmodule}`. Did you mean {hints.join(",", " or ")}?")
-			return null
+		if bests.best_items.not_empty then
+			for c in bests.best_items do hints.add "`{c.full_name}`"
+			error(qid, "Error: class `{qname}` not found in module `{mmodule}`. Did you mean {hints.join(",", " or ")}?")
+			return
 		end
 
-		error(ntype, "Error: class `{name}` not found in module `{mmodule}`.")
-		return null
+		error(qid, "Error: class `{qname}` not found in module `{mmodule}`.")
 	end
 
+	# List of already reported bad class names.
+	# Used to not perform and repeat hints again and again.
+	private var bad_class_names = new MultiHashMap[MModule, String]
+
 	# Return the static type associated to the node `ntype`.
 	# `mmodule` and `mclassdef` is the context where the call is made (used to understand formal types)
 	# In case of problem, an error is displayed on `ntype` and null is returned.
@@ -540,4 +570,19 @@ redef class AQclassid
 		end
 		return true
 	end
+
+	# The pretty name represented by self.
+	fun full_name: String
+	do
+		var res = n_id.text
+		var nqualified = n_qualified
+		if nqualified == null then return res
+		var ncid = nqualified.n_classid
+		if ncid != null then res = ncid.text + "::" + res
+		var nids = nqualified.n_id
+		if nids.not_empty then for n in nids.reverse_iterator do
+			res = n.text + "::" + res
+		end
+		return res
+	end
 end