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

diff --git a/src/location.nit b/src/location.nit
index 2737580..b65511d 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
@@ -42,7 +43,7 @@ class SourceFile
 	end
 
 	# Position of each line start
-	var line_starts: Array[Int] = new Array[Int]
+	var line_starts = new Array[Int]
 end
 
 # A location inside a source file
@@ -50,19 +51,28 @@ 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
-	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
-	end
+	# End of this location on `line_end`
+	var column_end: Int
 
 	# The index in the start character in the source
 	fun pstart: Int do return file.line_starts[line_start-1] + column_start-1
@@ -83,9 +93,7 @@ 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
@@ -100,6 +108,7 @@ class Location
 		return true
 	end
 
+	# Is `self` included (or equals) to `loc`?
 	fun located_in(loc: nullable Location): Bool do
 		if loc == null then return false
 
@@ -122,9 +131,12 @@ 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}"
@@ -136,6 +148,9 @@ class Location
 		end
 	end
 
+	# Return a location message according to an observer.
+	#
+	# Currently, if both are in the same file, the file information is not present in the result.
 	fun relative_to(loc: nullable Location): String do
 		var relative: Location
 		if loc != null and loc.file == self.file then
@@ -158,7 +173,7 @@ class Location
 		return column_end < other.column_end
 	end
 
-	# Return the associated line with the location highlihted with color and a carret under the starting position
+	# Return the associated line with the location highlighted with color and a caret under the starting position
 	# `color` must be and terminal escape sequence used as `"{escape}[{color}m;"`
 	# * `"0;31"` for red
 	# * `"1;31"` for bright red
@@ -171,13 +186,20 @@ 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
@@ -204,4 +226,3 @@ class Location
 		return "\t{lstart}{col}{lmid}{def}{lend}\n\t{indent}^"
 	end
 end
-