# Copyright 2003 Dave Abrahams
# Copyright 2002, 2003 Rene Rivera
# Copyright 2002, 2003, 2004 Vladimir Prus
# Distributed under the Boost Software License, Version 1.0.
# (See accompanying file LICENSE.txt or https://www.bfgroup.xyz/b2/LICENSE.txt)

# Various container classes.

# Base for container objects. This lets us construct recursive structures. That
# is containers with containers in them, specifically so we can tell literal
# values from node values.
#
class node
{
    rule __init__ (
        value ?  # Optional value to set node to initially.
    )
    {
        self.value = $(value) ;
    }

    # Set the value of this node, passing nothing will clear it.
    #
    rule set ( value * )
    {
        self.value = $(value) ;
    }

    # Get the value of this node.
    #
    rule get ( )
    {
        return $(self.value) ;
    }
}


# A simple vector. Interface mimics the C++ std::vector and std::list, with the
# exception that indices are one (1) based to follow Jam standard.
#
# TODO: Possibly add assertion checks.
#
class vector : node
{
    import numbers ;
    import utility ;
    import sequence ;

    rule __init__ (
        values *  # Initial contents of vector.
    )
    {
        node.__init__ ;
        self.value = $(values) ;
    }

    # Get the value of the first element.
    #
    rule front ( )
    {
        return $(self.value[1]) ;
    }

    # Get the value of the last element.
    #
    rule back ( )
    {
        return $(self.value[-1]) ;
    }

    # Get the value of the element at the given index, one based. Access to
    # elements of recursive structures is supported directly. Specifying
    # additional index values recursively accesses the elements as containers.
    # For example: [ $(v).at 1 : 2 ] would retrieve the second element of our
    # first element, assuming the first element is a container.
    #
    rule at (
        index  # The element index, one based.
        : *  # Additional indices to access recursively.
    )
    {
        local r = $(self.value[$(index)]) ;
        if $(2)
        {
            r = [ $(r).at $(2) : $(3) : $(4) : $(5) : $(6) : $(7) : $(8) : $(9) ] ;
        }
        return $(r) ;
    }

    # Get the value contained in the given element. This has the same
    # functionality and interface as "at" but in addition gets the value of the
    # referenced element, assuming it is a "node".
    #
    rule get-at (
        index  # The element index, one based.
        : *  # Additional indices to access recursively.
    )
    {
        local r = $(self.value[$(index)]) ;
        if $(2)
        {
            r = [ $(r).at $(2) : $(3) : $(4) : $(5) : $(6) : $(7) : $(8) : $(9) ] ;
        }
        return [ $(r).get ] ;
    }

    # Insert the given value into the front of the vector pushing the rest of
    # the elements back.
    #
    rule push-front (
        value  # Value to become first element.
    )
    {
        self.value = $(value) $(self.value) ;
    }

    # Remove the front element from the vector. Does not return the value. No
    # effect if vector is empty.
    #
    rule pop-front ( )
    {
        self.value = $(self.value[2-]) ;
    }

    # Add the given value at the end of the vector.
    #
    rule push-back (
        value  # Value to become back element.
    )
    {
        self.value += $(value) ;
    }

    # Remove the back element from the vector. Does not return the value. No
    # effect if vector is empty.
    #
    rule pop-back ( )
    {
        self.value = $(self.value[1--2]) ;
    }

    # Insert the given value at the given index, one based. The values at and to
    # the right of the index are pushed back to make room for the new value.
    # If the index is passed the end of the vector the element is added to the
    # end.
    #
    rule insert (
        index  # The index to insert at, one based.
        : value  # The value to insert.
    )
    {
        local left = $(self.value[1-$(index)]) ;
        local right = $(self.value[$(index)-]) ;
        if $(right)-is-not-empty
        {
            left = $(left[1--2]) ;
        }
        self.value = $(left) $(value) $(right) ;
    }

    # Remove one or more elements from the vector. The range is inclusive, and
    # not specifying an end is equivalent to the [start, start] range.
    #
    rule erase (
        start  # Index of first element to remove.
        end ?  # Optional, index of last element to remove.
    )
    {
        end ?= $(start) ;
        local left = $(self.value[1-$(start)]) ;
        left = $(left[1--2]) ;
        local right = $(self.value[$(end)-]) ;
        right = $(right[2-]) ;
        self.value = $(left) $(right) ;
    }

    # Remove all elements from the vector.
    #
    rule clear ( )
    {
        self.value = ;
    }

    # The number of elements in the vector.
    #
    rule size ( )
    {
        return [ sequence.length $(self.value) ] ;
    }

    # Returns "true" if there are NO elements in the vector, empty otherwise.
    #
    rule empty ( )
    {
        if ! $(self.value)-is-not-empty
        {
            return true ;
        }
    }

    # Returns the textual representation of content.
    #
    rule str ( )
    {
        return "[" [ sequence.transform utility.str : $(self.value) ] "]" ;
    }

    # Sorts the vector inplace, calling 'utility.less' for comparisons.
    #
    rule sort ( )
    {
        self.value = [ sequence.insertion-sort $(self.value) : utility.less ] ;
    }

    # Returns true if content is equal to the content of other vector. Uses
    # 'utility.equal' for comparison.
    #
    rule equal ( another )
    {
        local mismatch ;
        local size = [ size ] ;
        if $(size) = [ $(another).size ]
        {
            for local i in [ numbers.range 1 $(size) ]
            {
                if ! [ utility.equal [ at $(i) ] [ $(another).at $(i) ] ]
                {
                    mismatch = true ;
                }
            }
        }
        else
        {
            mismatch = true ;
        }

        if ! $(mismatch)
        {
            return true ;
        }
    }
}


rule __test__ ( )
{
    import assert ;
    import "class" : new ;

    local v1 = [ new vector ] ;
    assert.true $(v1).equal $(v1) ;
    assert.true $(v1).empty ;
    assert.result 0 : $(v1).size ;
    assert.result "[" "]" : $(v1).str ;
    $(v1).push-back b ;
    $(v1).push-front a ;
    assert.result "[" a b "]" : $(v1).str ;
    assert.result a : $(v1).front ;
    assert.result b : $(v1).back ;
    $(v1).insert 2 : d ;
    $(v1).insert 2 : c ;
    $(v1).insert 4 : f ;
    $(v1).insert 4 : e ;
    $(v1).pop-back ;
    assert.result 5 : $(v1).size ;
    assert.result d : $(v1).at 3 ;
    $(v1).pop-front ;
    assert.result c : $(v1).front ;
    assert.false $(v1).empty ;
    $(v1).erase 3 4 ;
    assert.result 2 : $(v1).size ;

    local v2 = [ new vector q w e r t y ] ;
    assert.result 6 : $(v2).size ;
    $(v1).push-back $(v2) ;
    assert.result 3 : $(v1).size ;
    local v2-alias = [ $(v1).back ] ;
    assert.result e : $(v2-alias).at 3 ;
    $(v1).clear ;
    assert.true $(v1).empty ;
    assert.false $(v2-alias).empty ;
    $(v2).pop-back ;
    assert.result t : $(v2-alias).back ;

    local v3 = [ new vector ] ;
    $(v3).push-back [ new vector 1 2 3 4 5 ] ;
    $(v3).push-back [ new vector a b c ] ;
    assert.result "[" "[" 1 2 3 4 5 "]" "[" a b c "]" "]" : $(v3).str ;
    $(v3).push-back [ new vector [ new vector x y z ] [ new vector 7 8 9 ] ] ;
    assert.result 1 : $(v3).at 1 : 1 ;
    assert.result b : $(v3).at 2 : 2 ;
    assert.result a b c : $(v3).get-at 2 ;
    assert.result 7 8 9 : $(v3).get-at 3 : 2 ;

    local v4 = [ new vector 4 3 6 ] ;
    $(v4).sort ;
    assert.result 3 4 6 : $(v4).get ;
    assert.false $(v4).equal $(v3) ;

    local v5 = [ new vector 3 4 6 ] ;
    assert.true $(v4).equal $(v5) ;
    # Check that vectors of different sizes are considered non-equal.
    $(v5).pop-back ;
    assert.false $(v4).equal $(v5) ;

    local v6 = [ new vector [ new vector 1 2 3 ] ] ;
    assert.true $(v6).equal [ new vector [ new vector 1 2 3 ] ] ;

    local v7 = [ new vector 111 222 333 ] ;
    assert.true $(v7).equal $(v7) ;
    $(v7).insert 4 : 444 ;
    assert.result 111 222 333 444 : $(v7).get ;
    $(v7).insert 999 : xxx ;
    assert.result 111 222 333 444 xxx : $(v7).get ;

    local v8 = [ new vector "" "" "" ] ;
    assert.true $(v8).equal $(v8) ;
    assert.false $(v8).empty ;
    assert.result 3  : $(v8).size ;
    assert.result "" : $(v8).at 1 ;
    assert.result "" : $(v8).at 2 ;
    assert.result "" : $(v8).at 3 ;
    assert.result    : $(v8).at 4 ;
    $(v8).insert 2 : 222 ;
    assert.result 4 : $(v8).size ;
    assert.result "" 222 "" "" : $(v8).get ;
    $(v8).insert 999 : "" ;
    assert.result 5 : $(v8).size ;
    assert.result "" 222 "" "" "" : $(v8).get ;
    $(v8).insert 999 : xxx ;
    assert.result 6 : $(v8).size ;
    assert.result "" 222 "" "" "" xxx : $(v8).get ;

    # Regression test for a bug causing vector.equal to compare only the first
    # and the last element in the given vectors.
    local v9 = [ new vector 111 xxx 222 ] ;
    local v10 = [ new vector 111 yyy 222 ] ;
    assert.false $(v9).equal $(v10) ;
}
