Class: HDLRuby::Low::Case

Inherits:
Statement
  • Object
show all
Defined in:
lib/HDLRuby/hruby_db.rb,
lib/HDLRuby/hruby_low.rb,
lib/HDLRuby/hruby_low2c.rb,
lib/HDLRuby/hruby_low2seq.rb,
lib/HDLRuby/hruby_low2vhd.rb,
lib/HDLRuby/hruby_verilog.rb,
lib/HDLRuby/hruby_low2high.rb,
lib/HDLRuby/hruby_low_cleanup.rb,
lib/HDLRuby/hruby_low_mutable.rb,
lib/HDLRuby/hruby_low_skeleton.rb,
lib/HDLRuby/hruby_low_with_var.rb,
lib/HDLRuby/hruby_low_fix_types.rb,
lib/HDLRuby/hruby_low_bool2select.rb,
lib/HDLRuby/hruby_low_without_select.rb,
lib/HDLRuby/hruby_low_without_namespace.rb

Overview

Extends the When class with functionality for moving the declarations to the upper namespace.

Direct Known Subclasses

High::Case

Constant Summary

Constants included from Low2Symbol

Low2Symbol::Low2SymbolPrefix, Low2Symbol::Low2SymbolTable, Low2Symbol::Symbol2LowTable

Instance Attribute Summary collapse

Attributes included from Hparent

#parent

Instance Method Summary collapse

Methods inherited from Statement

#add_blocks_code, #block, #break_types!, #top_block, #top_scope, #with_boolean!

Methods included from Low2Symbol

#to_sym

Constructor Details

#initialize(value, default = nil, whens = []) ⇒ Case

Creates a new case statement whose excution flow is decided from +value+ with a possible cases given in +whens+ and +default

  • (can be set later)


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# File 'lib/HDLRuby/hruby_low.rb', line 2996

def initialize(value, default = nil, whens = [])
    # Check and set the value.
    unless value.is_a?(Expression)
        raise AnyError, "Invalid class for a value: #{value.class}"
    end
    @value = value
    # And set its parent.
    value.parent = self
    # Checks and set the default case if any.
    self.default = default if default
    # Check and add the whens.
    @whens = []
    whens.each { |w| self.add_when(w) }
end

Instance Attribute Details

#default ⇒ Object

The default block.



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# File 'lib/HDLRuby/hruby_low.rb', line 2991

def default
  @default
end

#value ⇒ Object (readonly)

The tested value



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# File 'lib/HDLRuby/hruby_low.rb', line 2988

def value
  @value
end

Instance Method Details

#add_when(w) ⇒ Object

Adds possible when case +w+.



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# File 'lib/HDLRuby/hruby_low.rb', line 3050

def add_when(w)
    # Check +w+.
    unless w.is_a?(When)
        raise AnyError, "Invalid class for a when: #{w.class}"
    end
    # Add it.
    @whens << w
    # And set the parent of +w+.
    w.parent = self
end

#blocks2seq! ⇒ Object

Converts the par sub blocks to seq.



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# File 'lib/HDLRuby/hruby_low2seq.rb', line 154

def blocks2seq!
    # Recurse on the whens.
    self.each_when(&:blocks2seq!)
    # Converts the default if any.
    self.default.blocks2seq! if self.default
    return self
end

#boolean_in_assign2select! ⇒ Object

Converts booleans in assignments to select operators.



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# File 'lib/HDLRuby/hruby_low_bool2select.rb', line 109

def boolean_in_assign2select!
    # No need to apply on the value!
    # # Apply on the value.
    # self.set_value!(self.value.boolean_in_assign2select)
    # Apply on the whens.
    self.each_when(&:boolean_in_assign2select!)
    # Apply on the default if any.
    self.default.boolean_in_assign2select! if self.default
    return self
end

#clone ⇒ Object

Clones the Case (deeply)



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# File 'lib/HDLRuby/hruby_low.rb', line 3148

def clone
    return Case.new(@value.clone,@default.clone,(@whens.map do |w|
        w.clone
    end) )
end

#delete_unless!(keep) ⇒ Object

Removes the signals and corresponding assignments whose name is not in +keep+.



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# File 'lib/HDLRuby/hruby_low_cleanup.rb', line 157

def delete_unless!(keep)
    # Recurse on the whens.
    self.each_when {|w| w.delete_unless!(keep) }
    # Recurse on the default if any.
    self.default.delete_unless!(keep) if self.default
end

#delete_when!(w) ⇒ Object

Delete a when.



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# File 'lib/HDLRuby/hruby_low_mutable.rb', line 795

def delete_when!(w)
    @whens.delete(w)
end

#each_block(&ruby_block) ⇒ Object

Iterates over the sub blocks.



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# File 'lib/HDLRuby/hruby_low.rb', line 3113

def each_block(&ruby_block)
    # No ruby block? Return an enumerator.
    return to_enum(:each_block) unless ruby_block
    # A ruby block?
    # Apply it on each when's block.
    self.each_when { |w| w.each_block(&ruby_block) }
    # And apply it on the default if any.
    ruby_block.call(@default) if @default
end

#each_block_deep(&ruby_block) ⇒ Object

Iterates over all the blocks contained in the current block.



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# File 'lib/HDLRuby/hruby_low.rb', line 3124

def each_block_deep(&ruby_block)
    # No ruby block? Return an enumerator.
    return to_enum(:each_block_deep) unless ruby_block
    # A ruby block?
    # Apply it on each when's block.
    self.each_when { |w| w.each_block_deep(&ruby_block) }
    # And apply it on the default if any.
    @default.each_block_deep(&ruby_block) if @default
end

#each_node(&ruby_block) ⇒ Object

Iterates over the children (including the value).

Returns an enumerator if no ruby block is given.



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# File 'lib/HDLRuby/hruby_low.rb', line 3091

def each_node(&ruby_block)
    # No ruby block? Return an enumerator.
    return to_enum(:each_node) unless ruby_block
    # A ruby block? Apply it on each child.
    ruby_block.call(@value)
    @whens.each(&ruby_block)
    ruby_block.call(@default) if @default
end

#each_node_deep(&ruby_block) ⇒ Object

Iterates over the nodes deeply if any.



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# File 'lib/HDLRuby/hruby_low.rb', line 3101

def each_node_deep(&ruby_block)
    # No ruby block? Return an enumerator.
    return to_enum(:each_node_deep) unless ruby_block
    # A ruby block? First apply it to current.
    ruby_block.call(self)
    # And recurse on the children
    @value.each_node_deep(&ruby_block)
    @whens.each { |w| w.each_node_deep(&ruby_block) }
    @default.each_node_deep(&ruby_block) if @default
end

#each_statement_deep(&ruby_block) ⇒ Object

Iterates over all the statements contained in the current statement.



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# File 'lib/HDLRuby/hruby_low.rb', line 3135

def each_statement_deep(&ruby_block)
    # No ruby statement? Return an enumerator.
    return to_enum(:each_statement_deep) unless ruby_block
    # A ruby block?
    # Apply it on self.
    ruby_block.call(self)
    # And apply it on each when's statement.
    self.each_when { |w| w.each_statement_deep(&ruby_block) }
    # And apply it on the default if any.
    @default.each_statement_deep(&ruby_block) if @default
end

#each_when(&ruby_block) ⇒ Object

Iterates over the match cases.

Returns an enumerator if no ruby block is given.



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# File 'lib/HDLRuby/hruby_low.rb', line 3081

def each_when(&ruby_block)
    # No ruby block? Return an enumerator.
    return to_enum(:each_when) unless ruby_block
    # A ruby block? Apply it on each when case.
    @whens.each(&ruby_block)
end

#eql?(obj) ⇒ Boolean

Comparison for hash: structural comparison.

Returns:

  • (Boolean) 


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# File 'lib/HDLRuby/hruby_low.rb', line 3012

def eql?(obj)
    return false unless obj.is_a?(Case)
    return false unless @value.eql?(obj.value)
    return false unless @whens.eql?(obj.instance_variable_get(:@whens))
    idx = 0
    obj.each_when do |w|
        return false unless @whens[idx].eql?(w)
        idx += 1
    end
    return false unless idx == @whens.size
    return false unless @default.eql?(obj.default)
    return true
end

#explicit_types! ⇒ Object

Explicit the types conversions in the case.



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# File 'lib/HDLRuby/hruby_low_fix_types.rb', line 129

def explicit_types!
    # Recurse on the value.
    self.set_value!(self.value.explicit_types)
    # Recurse on the whens, the match of each when must be of the
    # type of the value.
    self.each_when { |w| w.explicit_types!(self.value.type) }
    return self
end

#extract_declares! ⇒ Object

Extract the declares from the scope and returns them into an array.

NOTE: do not recurse into the sub scopes or behaviors!



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# File 'lib/HDLRuby/hruby_low_without_namespace.rb', line 619

def extract_declares!
    # Recurse on the whens.
    return self.each_when.map(&:extract_declares!)
    # Recurse on the default if any.
    self.default.extract_declares! if self.default
end

#extract_selects! ⇒ Object

Extract the Select expressions.

Note: the default is not treated.



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# File 'lib/HDLRuby/hruby_low_without_select.rb', line 173

def extract_selects!
    selects = []
    # Work on the value.
    self.set_value!(self.value.extract_selects_to!(selects))
    # Work on the whens.
    selects += self.each_when.map(&:extract_selects!).reduce(:+)
    return selects
end

#hash ⇒ Object

Hash function.



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# File 'lib/HDLRuby/hruby_low.rb', line 3027

def hash
    return [@value,@whens,@default].hash
end

#map_nodes!(&ruby_block) ⇒ Object

Maps on the children (including the value).



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# File 'lib/HDLRuby/hruby_low_mutable.rb', line 800

def map_nodes!(&ruby_block)
    # A block? Apply it on each child.
    @value = ruby_block.call(@value)
    map_whens!(&ruby_block)
    if @default then
        @default = ruby_block.call(@default)
        @default.parent = self unless @default.parent
    end
end

#map_whens!(&ruby_block) ⇒ Object

Maps on the whens.



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# File 'lib/HDLRuby/hruby_low_mutable.rb', line 786

def map_whens!(&ruby_block)
    @whens.map! do |w|
        w = ruby_block.call(w)
        w.parent = self unless w.parent
        w
    end
end

#mix?(mode = nil) ⇒ Boolean

Tell if there is a mix block. +mode+ is the mode of the upper block.

Returns:

  • (Boolean) 


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# File 'lib/HDLRuby/hruby_low2seq.rb', line 164

def mix?(mode = nil)
    # Recuse on the whens.
    return true if self.each_when.any? { |w| w.mix?(mode) }
    # Check the default if any.
    return self.default.mix?(mode)
end

#replace_expressions!(node2rep) ⇒ Object

Replaces sub expressions using +node2rep+ table indicating the node to replace and the corresponding replacement. Returns the actually replaced nodes and their corresponding replacement.

NOTE: the replacement is duplicated.



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# File 'lib/HDLRuby/hruby_low_mutable.rb', line 816

def replace_expressions!(node2rep)
    # First recurse on the children.
    res = {}
    self.each_node do |node|
        res.merge!(node.replace_expressions!(node2rep))
    end
    # Is there a replacement to do on the value?
    rep = node2rep[self.value]
    if rep then
        # Yes, do it.
        rep = rep.clone
        node = self.value
        # node.set_parent!(nil)
        self.set_value!(rep)
        # And register the replacement.
        res[node] = rep
    end

    return res
end

#replace_names!(former, nname) ⇒ Object

Replaces recursively +former+ name by +nname+ until it is redeclared.



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# File 'lib/HDLRuby/hruby_low_without_namespace.rb', line 627

def replace_names!(former,nname)
    # Recurse on the value.
    self.value.replace_names!(former,nname)
    # Recurse on the whens.
    self.each_when {|w| w.replace_names!(former,nname) }
    # Recurse on the default.
    self.default.replace_names!(former,nname) if self.default
end

#set_default!(default) ⇒ Object

Sets the default.



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# File 'lib/HDLRuby/hruby_low_mutable.rb', line 780

def set_default!(default)
    # Checks and set the default case if any.
    self.default = default
end

#set_value!(value) ⇒ Object

Sets the value.



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# File 'lib/HDLRuby/hruby_low_mutable.rb', line 769

def set_value!(value)
    # Check and set the value.
    unless value.is_a?(Expression)
        raise AnyError, "Invalid class for a value: #{value.class}"
    end
    @value = value
    # And set its parent.
    value.parent = self
end

#to_c(level = 0) ⇒ Object

Generates the text of the equivalent HDLRuby::High code. +level+ is the hierachical level of the object.



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# File 'lib/HDLRuby/hruby_low2c.rb', line 1172

def to_c(level = 0)
    res = ""
    # Compute the selection value.
    res << "{\n"
    res << " " * (level+1)*3
    res << "Value value = " << self.value.to_c(level+1) << ";\n"
    # Ensure the selection value is testable.
    res << " " * (level+1)*3
    res << "if (is_defined_value(value)) {\n"
    # The condition is testable.
    # Generate the case as a succession of if statements.
    first = true
    self.each_when do |w|
        res << " " * (level+2)*3
        if first then
            first = false
        else
            res << "else "
        end
        res << "if (value2integer(value) == "
        res << "value2integer(" << w.match.to_c(level+2) << ")) {\n"
        res << w.statement.to_c(level+3)
        res << " " * (level+2)*3
        res << "}\n"
    end
    if self.default then
        res << " " * (level+2)*3
        res << "else {\n"
        res << self.default.to_c(level+3)
        res << " " * (level+2)*3
        res << "}\n"
    end
    # Close the case.
    res << " " * (level+1)*3
    res << "}\n"
    res << " " * (level)*3
    res << "}\n"
    # Return the resulting string.
    return res
end

#to_high(level = 0) ⇒ Object

Generates the text of the equivalent HDLRuby::High code. +level+ is the hierachical level of the object.



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# File 'lib/HDLRuby/hruby_low2high.rb', line 400

def to_high(level = 0)
    # The result string.
    res = " " * (level*3)
    # Generate the test.
    res << "hcase " << self.value.to_high(level) << "\n"
    # Generate the whens.
    self.each_when do |w|
        res << w.to_high(level)
    end
    # Generatethe default.
    if self.default then
        res << " " * (level*3)
        res << "helse do\n"
        res << self.default.to_high(level+1)
        res << " " * (level*3)
        res << "end\n"
    end
    # Return the resulting string.
    return res
end

#to_upper_space! ⇒ Object

Moves the declarations to the upper namespace.



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# File 'lib/HDLRuby/hruby_low_without_namespace.rb', line 609

def to_upper_space!
    # Recurse on the whens.
    self.each_when(&:to_upper_space!)
    # Recurse on the default if any.
    self.default.to_upper_space! if self.default
end

#to_verilog(mode = nil) ⇒ Object 



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# File 'lib/HDLRuby/hruby_verilog.rb', line 1389

def to_verilog(mode = nil)

    if ($space_count == 0) then
        result = "   " * ($space_count) # Indented based on space_count.
    else
        result = ""
    end
    $space_count += 1                 # Add count to be used for indentation.

    result = ""
    result << "case(#{self.value.to_verilog})\n"

    # n the case statement, each branch is partitioned by when. Process each time when.
    self.each_when do |whens| 
        # Reads and stores the numbers and expressions stored in when.
        result << "      " + "   " *$space_count + "#{whens.match.to_verilog}: "
        if whens.statement.each_statement.count > 1 then
            result << "begin\n"
            whens.statement.each_statement do |statement|
                result << "                  "+ "   " *$space_count +"#{statement.to_verilog}"
            end
            result << "             " + "   " *$space_count + "end\n"
        elsif whens.statement.each_statement.count == 1 then
            whens.statement.each_statement do |statement|
                result << "#{statement.to_verilog}"
            end
        end
    end
    # The default part is stored in default instead of when. Reads and processes in the same way as when.
    if self.default.each_statement.count > 1 then
        result << "      " + "   " *$space_count + "default: begin\n"
        self.default.each_statement do |statement|
            result << "                  " + "   " *$space_count + "#{statement.to_verilog}"
        end
        result << "                  end\n"
    elsif self.default.each_statement.count == 1 then
        result << "      " + "   " *$space_count + "default: "
        self.default.each_statement do |statement|
            result << "#{statement.to_verilog}"
        end
    end  
    result << "   " + "   " *$space_count + "endcase\n" # Conclusion.

    $space_count -= 1           # Since the output ends, reduce the count.
    return result               # Return case after translation.
end

#to_vhdl(vars, level = 0) ⇒ Object

Generates the text of the equivalent HDLRuby::High code. +vars+ is the list of the variables and +level+ is the hierachical level of the object.



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# File 'lib/HDLRuby/hruby_low2vhd.rb', line 934

def to_vhdl(vars,level = 0)
    # The result string.
    res = " " * (level*3)
    # Generate the test.
    res << "case " << self.value.to_vhdl(level) << " is\n"
    # Generate the whens.
    self.each_when do |w|
        res << w.to_vhdl(vars,self.value.type,level)
    end
    # Generate teh default if any.
    if self.default then
        res << " " * (level*3)
        res << "when others =>\n"
        res << self.default.to_vhdl(vars,level+1)
    else
        # NOTE: some VHDL parsers are very picky about others,
        # even though all the cases have been treated through
        # "when" statements.
        res << " " * (level*3)
        res << "when others =>\n"
    end
    # Close the case.
    res << " " * (level*3)
    res << "end case;\n"
    # Return the resulting string.
    return res
end

#with_var(upper = nil) ⇒ Object

Converts to a variable-compatible case where +upper+ is the upper block if any.

NOTE: the result is a new case.



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# File 'lib/HDLRuby/hruby_low_with_var.rb', line 296

def with_var(upper = nil)
    ndefault = self.default ? self.default.clone : nil
    return Case.new(self.value.clone,ndefault,
                    self.each_when.map {|w| w.with_var(upper) })
end