What is the output of the following Code?

Develop a complete scanner. Write a short report describing the work performed. Include the source program, input and output. You must show the execution of this program by using several relevant source lines as input, the program must show a list of the tokens scanned.

Grammar for the (subset of Lua) language

Syntax Analyzer

function id ( ) end

|

| | | |

if then else end while do end -> id -> repeat until print ( )

le_operator | lt_operator | ge_operator | gt_operator | eq_operator | ne_operator

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add_operator | sub_operator | mul_operator | div_operator

Lexical Analyzer

id letter

CS4308 Project 2

literal_integer digit literal_integer | digit assignment_operator = le_operator <= lt_operator <

ge_operator >=

gt_operator > eq_operator = = ne_operator ~= add_operator + sub_operator - mul_operator * div_operator /

ANS:-

Given that,

This project consists of developing an interpreter for a minimal form (subset) of the Lua language. This minimal form of Lua has only 1 data type, integer, and the only identifiers are single letters. Lua is not case sensitive. The specification of the grammar is given below.

The interpreter will process a Lua program and build some intermediate data structures. These data structures will then be interpreted to execute the program. All tokens in this language are separated by white space. The parsing algorithm should detect any syntactical or semantic error. The first such error discovered should cause an appropriate error message to be printed, and then the interpreter should terminate. Run-time errors should also be detected with appropriate error messages being printed.

PROGRAM:-

form = Gui.Form{ Text="Ledger Sheet", Width=700, Height=500, StartPosition="CenterScreen", Gui.SplitContainer { Dock="Fill", Width=700, SplitterDistance=200, Gui.TreeView{ Name="treeviewCategory", Dock="Fill", HideSelection=false }, Gui.Panel{ Dock="Fill", Gui.ListView{ Name="listviewEntries", Dock="Fill", View="Details", GridLines=true, FullRowSelect=true, ContextMenuStrip=Gui.ContextMenuStrip { Gui.ToolStripMenuItem { Text="Delete", Click=function(sender,e) DeleteEntry() end } } }, Gui.StatusStrip { Name="statusStrip", Dock="Bottom" } } }, Gui.ToolStrip{ Dock="Top", Top=0, Left=0, Width=700, Height=25, Gui.ToolStripButton { Name="btnOpen", Text="&Open", Width=88, Height=22, Image="icon\\open.png" }, Gui.ToolStripButton { Name="btnSave", Text="&Save", Width=88, Height=22, Image="icon\\save.png" }, Gui.ToolStripButton { Name="btnAdd", Text="&Add", Width=88, Height=22, Image="icon\\add.png" }, } } incomeNode = treeviewCategory.Nodes.Add("Income") outgoNode = treeviewCategory.Nodes.Add("Outgo") listviewEntries.Columns.Add(Gui.ColumnHeader{ Text="Date", Width=100 }) listviewEntries.Columns.Add(Gui.ColumnHeader{ Text="Detail", Width=260 }) listviewEntries.Columns.Add(Gui.ColumnHeader{ Text="Amount", Width=120 }) dialog = Gui.Form{ Text="Add Entry", Width=320, Height=220, StartPosition="CenterParent", FormBorderStyle="FixedDialog", ShowInTaskbar = false; Gui.Label{ Text="Subject:", Width=60, Height=17, Top=14, Left=12 }, Gui.RadioButton { Name="dialog_Income", Text="Income", Width=80, Height=20, Top=9, Left=80 }, Gui.RadioButton { Name="dialog_Outgo", Text="Outgo", Width=80, Height=20, Top=9, Left=160, Checked=true }, Gui.Label{ Text="Category:", Width=60, Height=17, Top=40, Left=12 }, Gui.ComboBox { Name="dialog_Category", Width=160, Height=20, Top=36, Left=80 }, Gui.Label{ Text="Detail:", Width=60, Height=17, Top=68, Left=12 }, Gui.TextBox { Name="dialog_Detail", Width=160, Height=20, Top=64, Left=80 }, Gui.Label{ Text="Amount:", Width=60, Height=17, Top=96, Left=12 }, Gui.TextBox { Name="dialog_Amount", Width=128, Height=20, Top=92, Left=80 }, Gui.Label{ Text="Date:", Width=60, Height=17, Top=128, Left=12 }, Gui.DateTimePicker { Name="dialog_Date", Width=128, Height=21, Top=124, Left=80, Format="Short" }, Gui.Button{ Text="OK", Name="dialog_btnOK", Width=80, Height=23, Top=156, Left=130, DialogResult="OK" }, Gui.Button{ Text="Cancel", Name="dialog_btnCancel", Width=80, Height=23, Top=156, Left=224, DialogResult="Cancel" }, AcceptButton=dialog_btnOK, CancelButton=dialog_btnCancel } Entries = {} btnAdd.Click = function (sender,e) dialog_Detail.Text = "" dialog_Amount.Text = "" if treeviewCategory.SelectedNode ~= nil and treeviewCategory.SelectedNode.Tag ~= nil then dialog_Category.Text = treeviewCategory.SelectedNode.Text end if dialog.ShowDialog(form) == "OK" then local subject = dialog_Income.Checked and "income" or "outgo" local category = dialog_Category.Text local detail = dialog_Detail.Text local amount = dialog_Amount.Text local date = dialog_Date.Value.ToShortDateString() local entry = {date, subject, category, detail, amount} table.insert(Entries, entry) local categoryNode = UpdateCategoryTree(entry) if treeviewCategory.SelectedNode == categoryNode then AddEntryToListView(entry) else treeviewCategory.SelectedNode = categoryNode end end end function FindCategoryNode(entry) local subject = entry[2] local category = entry[3] local subjectNode = subject == "outgo" and outgoNode or incomeNode local subNodes = subjectNode.Nodes.Find(category, false) if #subNodes == 0 then return nil, subjectNode else return subNodes[1], subjectNode end end function UpdateCategoryTree(entry) local categoryNode, subjectNode = FindCategoryNode(entry) if categoryNode == nil then local category = entry[3] categoryNode = subjectNode.Nodes.Add(category, category) categoryNode.Tag = {} dialog_Category.Items.Add(category) end table.insert(categoryNode.Tag, entry) return categoryNode end treeviewCategory.AfterSelect = function (sender, e) local entries = treeviewCategory.SelectedNode.Tag if entries ~= nil then listviewEntries.Items.Clear() for _,entry in ipairs(entries) do AddEntryToListView(entry) end end end function AddEntryToListView(entry) local item = Gui.ListViewItem{ Text=entry[1] } item.SubItems.Add(entry[4]) item.SubItems.Add(entry[5]) item.Tag = entry listviewEntries.Items.Add(item) end function DeleteEntry() local item = listviewEntries.SelectedItems[1] local entry = item.Tag if entry ~= nil then local categoryNode = FindCategoryNode(entry) table.removeitem(categoryNode.Tag, entry) table.removeitem(Entries, entry) listviewEntries.Items.Remove(item) end end btnSave.Click = function (sender, e) local sfd = Gui.SaveFileDialog{ Title="Save data", Filter="data file(*.dat)|*.dat" } if sfd.ShowDialog() == "OK" then local file = io.open(sfd.FileName, "w") file:write("Entries = { ") for _,entry in ipairs(Entries) do file:write('{"', table.concat(entry, '", "'), '"}, ') end file:write('}') file:close() end end btnOpen.Click = function (sender, e) local ofd = Gui.OpenFileDialog{ Title="Open data file", Filter="data file(*.dat)|*.dat" } if ofd.ShowDialog() == "OK" then dofile(ofd.FileName) incomeNode.Nodes.Clear() outgoNode.Nodes.Clear() dialog_Category.Items.Clear() for _,entry in ipairs(Entries) do UpdateCategoryTree(entry) end treeviewCategory.ExpandAll() listviewEntries.Items.Clear() end end