Rename REAMDE to README.md
[nit.git] / src / location.nit
index b3e8458..1a27697 100644 (file)
@@ -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
@@ -50,18 +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
@@ -100,6 +169,7 @@ 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 +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}"
@@ -136,6 +209,9 @@ 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 +234,7 @@ 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 +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[line_end+1] != '\n' and string[line_end+1] != '\r' do
+               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
@@ -193,9 +276,9 @@ class Location
                        lmid = ""
                        lend = ""
                end
-               var indent = new Buffer
+               var indent = new FlatBuffer
                for j in [line_start..line_start+l.column_start-1[ do
-                       if string[j] == '\t' then
+                       if string.chars[j] == '\t' then
                                indent.add '\t'
                        else
                                indent.add ' '
@@ -204,4 +287,3 @@ class Location
                return "\t{lstart}{col}{lmid}{def}{lend}\n\t{indent}^"
        end
 end
-