Added programming language fundamentals code. More to come.

OSU Coursework/CS 381 - Programming Language Fundamentals/Homework 3/MiniMiniLogoSem.perrenc.hs

@@ -0,0 +1,86 @@
+module MiniMiniLogoSem where
+
+import MiniMiniLogo
+import Render
+
+
+--
+-- * Semantics of MiniMiniLogo
+--
+
+-- NOTE:
+--   * MiniMiniLogo.hs defines the abstract syntax of MiniMiniLogo and some
+--     functions for generating MiniMiniLogo programs. It contains the type
+--     definitions for Mode, Cmd, and Prog.
+--   * Render.hs contains code for rendering the output of a MiniMiniLogo
+--     program in HTML5. It contains the types definitions for Point and Line.
+
+-- | A type to represent the current state of the pen.
+type State = (Mode,Point)
+
+-- | The initial state of the pen.
+start :: State
+start = (Up,(0,0))
+
+-- | A function that renders the image to HTML. Only works after you have
+--   implemented `prog`. Applying `draw` to a MiniMiniLogo program will
+--   produce an HTML file named MiniMiniLogo.html, which you can load in
+--   your browswer to view the rendered image.
+draw :: Prog -> IO ()
+draw p = let (_,ls) = prog p start in toHTML ls
+
+
+-- Semantic domains:
+--   * Cmd:  State -> (State, Maybe Line)
+--   * Prog: State -> (State, [Line])
+
+
+-- | Semantic function for Cmd.
+--
+--   >>> cmd (Pen Down) (Up,(2,3))
+--   ((Down,(2,3)),Nothing)
+--
+--   >>> cmd (Pen Up) (Down,(2,3))
+--   ((Up,(2,3)),Nothing)
+--
+--   >>> cmd (Move 4 5) (Up,(2,3))
+--   ((Up,(4,5)),Nothing)
+--
+--   >>> cmd (Move 4 5) (Down,(2,3))
+--   ((Down,(4,5)),Just ((2,3),(4,5)))
+--
+cmd :: Cmd -> State -> (State, Maybe Line)
+cmd (Pen pen_state) (_, new_point) =  ((pen_state, new_point), Nothing)
+cmd (Move mx my) (Up, (start_point)) = ((Up, (mx, my)), Nothing)
+cmd (Move mx my) (Down, (start_x, start_y)) = ((Down, (mx, my)), Just ((start_x, start_y),(mx, my)))
+
+
+-- | Semantic function for Prog.
+--
+--   >>> prog (nix 10 10 5 7) start
+--   ((Down,(15,10)),[((10,10),(15,17)),((10,17),(15,10))])
+--
+--   >>> prog (steps 2 0 0) start
+--   ((Down,(2,2)),[((0,0),(0,1)),((0,1),(1,1)),((1,1),(1,2)),((1,2),(2,2))])
+prog :: Prog -> State -> (State, [Line])
+prog [] prog_state = (prog_state, [])
+prog prog_list start_state = progLineListHelper prog_list (start_state, [])
+
+-- Helper function to handle keeping track of the line list as we move through the program elements      
+progLineListHelper :: Prog -> (State, [Line]) -> (State, [Line])
+progLineListHelper [] state_and_line_list = state_and_line_list
+progLineListHelper (progs_head:progs_tail) (initial_state, initial_line_list) = 
+    let (new_state, new_line_list) = cmd progs_head initial_state in
+    case new_line_list of 
+        Just new_line_list -> progLineListHelper progs_tail (new_state, initial_line_list ++ [new_line_list]) 
+        Nothing -> progLineListHelper progs_tail (new_state, initial_line_list)    
+
+
+--
+-- * Extra credit
+--
+
+-- | This should be a MiniMiniLogo program that draws an amazing picture.
+--   Add as many helper functions as you want.
+amazing :: Prog
+amazing = undefined