object = require './runtime'.object

exports.create indent stack = create indent stack () = {
    indents = [0]
    indentation regex = r/\r?\n( *)$/
    multi new line regex = r/\r?\n *\r?\n/
    
    is (text) multi new line =
        self.multi new line regex.test (text)
    
    (text) has new line () =
        self.indentation regex.test (text)
    
    indentation (new line) =
        self.indentation regex.exec (new line).1.length
    
    current indentation () =
        self.indents.0
    
    set indentation (text) =
        if (self.(text) has new line ())
            self.indents.unshift 'bracket'
            self.indents.unshift (self.indentation (text))
        else
            current = self.current indentation ()
            self.indents.unshift 'bracket'
            self.indents.unshift (current)
    
    unset indentation () =
        self.indents.shift ()

        tokens = []
        while ((self.indents.length > 0) && (self.indents.0 != 'bracket'))
            tokens.push '}'
            self.indents.shift ()
        
        self.indents.shift ()
        tokens
    
    tokens for eof () =
        tokens = []
        indents = self.indents.length

        while (indents > 1)
            tokens.push '}'
            --indents
        
        tokens.push 'eof'
    
        tokens
        
    
    tokens for new line (text) =
        if (self.(text) has new line ())
            current indentation = self.current indentation ()
            indentation = self.indentation (text)
    
            if (current indentation == indentation)
                [',']
            else if (current indentation < indentation)
                self.indents.unshift (indentation)
                ['@{']
            else
                tokens = []
            
                while (self.indents.0 > indentation)
                    tokens.push '}'
                    self.indents.shift ()
            
                if (self.is (text) multi new line)
                    tokens.push ','
            
                if (self.indents.0 < indentation)
                    tokens.push '@{'
                    self.indents.unshift (indentation)
            
                tokens
        else
            []
}