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

diff --git a/src/location.nit b/src/location.nit
index c092b28..1a27697 100644
--- a/src/location.nit
+++ b/src/location.nit
@@ -14,7 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# This module is used to model Nit source-file and locations in source-file
+# Nit source-file and locations in source-file
 module location
 
 # A raw text Nit source file
@@ -23,12 +23,13 @@ class SourceFile
 	var filename: String
 
 	# The content of the source
-	var string: String
+	var string: String is noinit
 
-	# Create a new sourcefile using a filename and a stream
-	init(filename: String, stream: IStream)
+	# The original stream used to initialize `string`
+	var stream: Reader
+
+	init
 	do
-		self.filename = filename
 		string = stream.read_all
 		line_starts[0] = 0
 	end
@@ -50,18 +51,88 @@ class Location
 	super Comparable
 	redef type OTHER: Location
 
+	# The associated source-file
 	var file: nullable SourceFile
+
+	# The starting line number (starting from 1)
+	#
+	# If `line_start==0` then the whole file is considered
 	var line_start: Int
+
+	# The stopping line number (starting from 1)
 	var line_end: Int
+
+	# Start of this location on `line_start`
+	#
+	# A `column_start` of 1 means the first column or character.
+	#
+	# If `column_start == 0` this location concerns the whole line.
+	#
+	# Require: `column_start >= 0`
 	var column_start: Int
+
+	# End of this location on `line_end`
 	var column_end: Int
 
-	init(f: nullable SourceFile, line_s: Int, line_e: Int, column_s: Int, column_e: Int) do
-		file = f
-		line_start = line_s
-		line_end = line_e
-		column_start = column_s
-		column_end = column_e
+	# Builds a location instance from its string representation.
+	#
+	# Examples:
+	#
+	# ~~~
+	# var loc = new Location.from_string("location.nit:82,2--105,8")
+	# assert loc.to_s == "location.nit:82,2--105,8"
+	#
+	# loc = new Location.from_string("location.nit")
+	# assert loc.to_s == "location.nit"
+	#
+	# loc = new Location.from_string("location.nit:82,2")
+	# assert loc.to_s == "location.nit:82,2--0,0"
+	#
+	# loc = new Location.from_string("location.nit:82--105")
+	# assert loc.to_s == "location.nit:82,0--105,0"
+	#
+	# loc = new Location.from_string("location.nit:82,2--105")
+	# assert loc.to_s == "location.nit:82,2--105,0"
+	#
+	# loc = new Location.from_string("location.nit:82--105,8")
+	# assert loc.to_s == "location.nit:82,0--105,8"
+	# ~~~
+	init from_string(string: String) do
+		self.line_start = 0
+		self.line_end = 0
+		self.column_start = 0
+		self.column_end = 0
+		# parses the location string and init position vars
+		var parts = string.split_with(":")
+		var filename = parts.shift
+		self.file = new SourceFile(filename, new FileReader.open(filename))
+		# split position
+		if parts.is_empty then return
+		var pos = parts.first.split_with("--")
+		# split start position
+		if pos.first.has(",") then
+			var pos1 = pos.first.split_with(",")
+			self.line_start = pos1[0].to_i
+			if pos1.length > 1 then
+				self.column_start = pos1[1].to_i
+			end
+		else
+			self.line_start = pos.first.to_i
+		end
+		# split end position
+		if pos.length <= 1 then return
+		if pos[1].has(",") then
+			var pos2 = pos[1].split_with(",")
+			if pos2.length > 1 then
+				self.line_end = pos2[0].to_i
+				self.column_end = pos2[1].to_i
+			else
+				self.line_end = self.line_start
+				self.column_end = pos2[0].to_i
+			end
+		else
+			self.line_end = pos[1].to_i
+		end
 	end
 
 	# The index in the start character in the source
@@ -83,9 +154,7 @@ class Location
 		return res
 	end
 
-	private var text_cache: nullable String
-
-	init with_file(f: SourceFile) do init(f,0,0,0,0)
+	private var text_cache: nullable String = null
 
 	redef fun ==(other: nullable Object): Bool do
 		if other == null then return false
@@ -123,9 +192,12 @@ class Location
 		var file_part = ""
 		if file != null then
 			file_part = file.filename
-			if file.filename.length > 0 then file_part += ":"
 		end
 
+		if line_start <= 0 then return file_part
+
+		if file != null and file.filename.length > 0 then file_part += ":"
+
 		if line_start == line_end then
 			if column_start == column_end then
 				return "{file_part}{line_start},{column_start}"
@@ -175,13 +247,20 @@ class Location
 
 		var l = self
 		var i = l.line_start
+		if i <= 0 then return ""
+
 		var line_start = l.file.line_starts[i-1]
 		var line_end = line_start
 		var string = l.file.string
 		while line_end+1 < string.length and string.chars[line_end+1] != '\n' and string.chars[line_end+1] != '\r' do
 			line_end += 1
 		end
-		var lstart = string.substring(line_start, l.column_start - 1)
+		var lstart
+		if l.column_start > 0 then
+			lstart = string.substring(line_start, l.column_start - 1)
+		else
+			lstart = ""
+		end
 		var cend
 		if i != l.line_end then
 			cend = line_end - line_start + 1