Adds receivers to filter and point structs

.gitignore

@@ -12,3 +12,5 @@
 # Output of the go coverage tool, specifically when used with LiteIDE
 *.out
 
+# Binary from `go build`
+filtress

filtress_notes.txt

@@ -77,13 +77,6 @@ MOD [op]int
 
 . . .
 
-Set fade time:
-# If set below zero, becomes zero
-
-FAD [op]int
-
-. . . 
-
 Doing loops:
 # The int after BEG represents the number of times to loop
 # At present, loops may not be nested

main.go

@@ -1,5 +1,14 @@
 package main
 
+import (
+	"flag"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"tildegit.org/sloum/filtress/parser"
+)
+
 type point struct {
 	x    int
 	y    int
@@ -7,21 +16,61 @@ type point struct {
 	maxY int
 }
 
-type color int
-type mode int
+type filter struct {
+	max int
+	min int
+	val int
+}
 
 type filterState struct {
-	red				color
-	green			color
-	blue			color
-	alpha			color
+	red      filter
+	green    filter
+	blue     filter
+	alpha    filter
 	location point
-	mod				mode
-	register	int
-	fade			uint
-	loop			uint
+	mode     filter
+}
+
+var variables = map[string]int{}
+
+func openFileFromPath(path string) *os.File {
+	file, err := os.Open(path)
+	if err != nil {
+		panic(err)
+	}
+
+	return file
 }
 
 func main() {
+	// Handle checking filter file argument
+	flag.Parse()
+	posArgs := flag.Args()
+	if len(posArgs) > 1 || len(posArgs) < 1 {
+		panic(fmt.Sprintf("Input error: Too many positional arguments. Expected one, received %d", len(flag.Args())))
+	}
+	fpath := posArgs[0]
+	fext := strings.ToUpper(filepath.Ext(fpath))
+	_, fname := filepath.Split(fpath)
+
+	if fext != ".FRS" {
+		panic(fmt.Sprintf("Input error: Incorrect filetype. Expected .FRS, received \".%s\"", fext))
+	}
+
+	// Open file and parse
+	fmt.Println("Filtress v0.2.0")
+	filterFile := openFileFromPath(fpath)
+	parser := parser.NewParser(filterFile)
+	fmt.Printf("Parsing file: %s ...\n", fname)
+	tree := parser.Parse()
+	if len(tree.Loops) > 0 {
+		fmt.Printf("File has %d procedures\n", len(tree.Loops))
+		fmt.Println("File is valid")
+	} else {
+		fmt.Println("Invalid input file")
+	}
+
+	fmt.Print(tree)
+	fmt.Println()
 
 }

parser/lexer.go

@@ -1,4 +1,4 @@
-package parse
+package parser
 
 import (
   "bufio"
@@ -48,11 +48,12 @@ func (s *scanner) unread() {
 
 
 func (s *scanner) scan() Token {
+  for {
     char := s.read()
 
     if isWhitespace(char) {
       s.unread()
-    return s.scanWhitespace()
+      s.scanWhitespace()
     } else if isLetter(char) {
       s.unread()
       return s.scanText()
@@ -61,19 +62,20 @@ func (s *scanner) scan() Token {
       return s.scanNumber()
     } else if char == '#' {
       s.unread()
-    return s.scanComment()
+      s.scanComment()
     } else if isOpperator(char) {
       return Token{Opperator, string(char)}
     } else if char == '\n' {
-    return Token{Newline,""}
+      return Token{Newline,"New Line"}
     } else if char == ':' {
-    return Token{Separator,""}
+      return Token{Separator,":"}
     } else if char == eof {
-    return Token{End, ""}
-  }
-
+      return Token{End, "eof"}
+    } else {
       return Token{Illegal, string(char)}
     }
+  }
+}
 
 
 func (s *scanner) scanWhitespace() Token {

parser/parser.go

@@ -1,4 +1,4 @@
-package parse
+package parser
 
 import (
   "io"
@@ -45,11 +45,6 @@ func (p *Parser) scan() (current Token) {
 		return p.buffer.token
 	}
 
-  for {
-    if current = p.s.scan(); current.kind != Whitespace && current.kind != Comment {
-      break
-    }
-  }
 	current = p.s.scan()
 	p.buffer.token = current
 	return
@@ -70,8 +65,13 @@ func (p *Parser) parseExpressions(equals bool) []Expression {
     if t.kind == Opperator {
       ex.Opperator = rune(t.val[0])
       t = p.scan()
-    } else {
+    } else if t.kind == Number || t.kind == Text {
       ex.Opperator = '='
+    } else if t.kind == Newline {
+      p.unscan()
+      break
+    } else {
+        panic(fmt.Sprintf("Parse error: Invalid token %q on \033[1mline %d\033[0m", t.val, p.row))
     }
 
     if t.kind == Number {
@@ -86,6 +86,7 @@ func (p *Parser) parseExpressions(equals bool) []Expression {
 
     exprs = append(exprs, ex)
 
+    t = p.scan()
     if t.kind == Separator {
       continue
     }
@@ -133,17 +134,12 @@ func (p *Parser) parseLoop() Loop {
   t := p.scan()
   l := Loop{}
 
-  if strings.ToUpper(t.val) == "LOOP" {
-    t = p.scan()
   if t.kind == Number {
     l.Counter, _ = strconv.Atoi(t.val)
   } else {
     panic(fmt.Sprintf("Parse error: Loop declared, but not followed by a number on \033[1mline %d\033[0m", p.row))
   }
-  } else {
-    p.unscan()
-    l.Counter = 1
-  }
+
   l.Procedures = make([]Procedure,0, 5)
 
   L:
@@ -163,6 +159,9 @@ func (p *Parser) parseLoop() Loop {
     case Number:
       panic(fmt.Sprintf("Parse error: Number %q outside of procedure call on \033[1mline %d\033[0m", t.val, p.row))
     case Text:
+      if strings.ToUpper(t.val) == "END" {
+        break L
+      }
       p.unscan()
       procedure := p.parseProcedure()
       l.Procedures = append(l.Procedures, procedure)
@@ -193,8 +192,15 @@ func (p *Parser) Parse() AST {
     case Number:
       panic(fmt.Sprintf("Parse error: Number %q outside of procedure call on \033[1mline %d\033[0m", t.val, p.row))
     case Text:
+      var loop Loop
+      if strings.ToUpper(t.val) == "BEG" {
+        loop = p.parseLoop()
+      } else {
         p.unscan()
-      loop := p.parseLoop()
+        loop = Loop{1, make([]Procedure, 0, 1)}
+        procedure := p.parseProcedure()
+        loop.Procedures = append(loop.Procedures, procedure)
+      }
       tree.Loops = append(tree.Loops, loop)
     }
   }
@@ -205,8 +211,7 @@ func (p *Parser) Parse() AST {
 func isValidProcedure(p string) bool {
   switch p {
     case "REG", "LOC", "BEG", "END", "RED",
-    "GRN", "BLU", "APH", "COL", "APY", "MOD",
-    "FAD":
+    "GRN", "BLU", "APH", "COL", "APY", "MOD":
       return true
   }
   return false
@@ -224,3 +229,5 @@ func isVariable(v string) bool {
 func NewParser(r io.Reader) *Parser {
 	return &Parser{s: NewScanner(r)}
 }
+
+

receivers.go

@@ -0,0 +1,96 @@
+package main
+
+import (
+	"fmt"
+	"tildegit.org/sloum/filtress/parser"
+)
+
+func (f *filter) update(change parser.Expression, vars map[string]int) {
+	opand := change.Opperand
+	if change.Variable != "" {
+		if val, ok := vars[change.Variable]; ok {
+			opand = val
+		} else {
+			panic(fmt.Sprintf("Runtime error: Encountered unknown variable %q", val))
+		}
+	}
+
+	switch change.Opperator {
+	case '+':
+		f.val += opand
+	case '-':
+		f.val -= opand
+	case '*':
+		f.val *= opand
+	case '/':
+		if opand == 0 {
+			f.val = 1
+		} else {
+			f.val /= opand
+		}
+	case '=':
+		f.val = opand
+	}
+	if f.val > f.max {
+		f.val %= f.max
+	}
+	if f.val < f.min {
+		f.val = f.max - f.val%f.max
+	}
+}
+
+func (p *point) update(change []parser.Expression, vars map[string]int) {
+	var totalX, totalY, val, opand, max int
+	var target *int
+
+	for i, e := range change {
+		if i == 0 {
+			target = &totalX
+			val = p.x
+			max = p.maxX
+		} else if i == 1 {
+			target = &totalY
+			val = p.y
+			max = p.maxY
+		} else {
+			break
+		}
+
+		if e.Variable != "" {
+			if val, ok := vars[e.Variable]; ok {
+				opand = val
+			} else {
+				panic(fmt.Sprintf("Runtime error: Encountered unknown variable %q", val))
+			}
+		} else {
+			opand = e.Opperand
+		}
+
+		switch e.Opperator {
+		case '+':
+			*target = val + opand
+		case '-':
+			*target = val - opand
+		case '*':
+			*target = val * opand
+		case '/':
+			if opand == 0 {
+				*target = 1
+			} else {
+				*target = val / opand
+			}
+		case '=':
+			*target = opand
+		}
+
+		if *target > max {
+			*target %= max
+		}
+
+		if *target < 0 {
+			*target = max - *target%max
+		}
+	}
+	p.x = totalX
+	p.y = totalY
+}

test.frs

@@ -0,0 +1,17 @@
+# First attempt at a filtress file!!
+MOD 1
+RED 100
+
+BEG 10
+LOC +100:WID
+BLU /300
+END
+
+#comment
+APY +100:+100
+
+
+
+
+
+