location: introduce `from_string` constructor to compose a location from its String...

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>

diff --git a/src/location.nit b/src/location.nit
index b65511d..1a27697 100644 (file)
--- a/src/location.nit
+++ b/src/location.nit
@@ -74,6 +74,67 @@ class Location
        # End of this location on `line_end`
        var column_end: Int
 
+       # 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
        fun pstart: Int do return file.line_starts[line_start-1] + column_start-1