}
func main() {
- //a := &AST{Op: imm, N: 5
- //b := &AST{Op: plus, A: a, B: &AST{Op: arg, N: 0}}
- input := "[ a b ] a*a + b*b"
- //value := []rune(input)
+ //TODO(josuer08): Change this for a argv reader and all of the printing can
+ // be moved to writing to a file or just use standalone with redirection not
+ //quite sure about it.
+ input := "[ a b ] ((a*b) + (5*5))-3"
variables, program := extractVariables(input)
+ //fmt.Println(variables, program)
+ Tree := AST{}
+ firstPass(variables, program, &Tree)
+ //fmt.Println(Tree)
+ secondPass(&Tree)
+ slices.Sort(variables)
+ thirdPass(&Tree, variables)
+ //printer(&Tree)
- fmt.Println(variables, program)
- var Tree AST
- firstPass(program, &Tree)
- //si es una letra y el stack esta sin setear pon en el A del stack un AST arg
- //si es una operacion setea la op en el stack
- //si es un abrir parentesis apunta al lado que este disponible del AST
- //si es una letra y ya esta seteada la op mete un AST arg a la otra letra
- //si es un cerrar parentesis coge para el pai.
+}
- //los numeros se portan justo como las letras.
+// printer si a function that prints in Reverse Pollish Notation the AST
+func printer(tree *AST) {
+ switch {
+ case tree.Op == imm:
+ fmt.Print(tree.Value)
+ case tree.Op == arg:
+ fmt.Printf("%c", tree.Value)
+ default:
+ fmt.Print("(")
+ switch tree.Op {
+ case min:
+ fmt.Print("-")
+ case plus:
+ fmt.Print("+")
+ case div:
+ fmt.Print("/")
+ case mul:
+ fmt.Print("*")
+ }
+ fmt.Print(",")
+ printer(tree.Left)
+ fmt.Print(",")
+ printer(tree.Right)
+ fmt.Print(")")
+ }
}
+// firstPass Is a function that makes the first pass of the compiler,
+// it converts the variable and program into an AST
func firstPass(variables, program []rune, node *AST) {
+ pass := node
switch program[0] {
case '-':
node.Op = min
- firstPass(variables, program[1:], node)
case '+':
node.Op = plus
- firstPass(variables, program[1:], node)
case '*':
node.Op = mul
- firstPass(variables, program[1:], node)
case '/':
node.Op = div
- firstPass(variables, program[1:], node)
case '(':
- if node.Left != nil {
- firstPass(variables, program[1:], node.Left)
+ if node.Left == nil {
+ node.Left = &AST{}
+ node.Left.Parent = node
+ pass = node.Left
} else {
- firstPass(variables, program[1:], node.Right)
+ node.Right = &AST{}
+ node.Right.Parent = node
+ pass = node.Right
}
case ')':
- return
+ pass = node.Parent
default:
if program[0] > 47 && program[0] < 58 {
var zeroOp op
if node.Op == zeroOp {
node.Left = &AST{Op: imm, Value: int(program[0]) - 48}
- firstPass(variables, program[1:], node)
- //a := &AST{Op: imm, N: 5
} else {
node.Right = &AST{Op: imm, Value: int(program[0]) - 48}
- firstPass(variables, program[1:], node)
}
} else if slices.Contains(variables, program[0]) {
- var zeroOp op
- if node.Op == zeroOp {
- node.Left = &AST{Op: imm, Value: int(program[0]) - 48}
- firstPass(variables, program[1:], node)
- //a := &AST{Op: imm, N: 5
+ if node.Op != plus && node.Op != min && node.Op != mul && node.Op != div {
+ node.Left = &AST{Op: arg, Value: int(program[0])}
} else {
- node.Right = &AST{Op: imm, Value: int(program[0]) - 48}
- firstPass(variables, program[1:], node)
+ node.Right = &AST{Op: arg, Value: int(program[0])}
}
+ }
+ }
+ if len(program) > 1 {
+ firstPass(variables, program[1:], pass)
+ }
+}
+
+// secondPass takes an AST and reduces the operations that only include imm
+// values so the program results in a more compact one with precalculated imms
+func secondPass(node *AST) {
+ if node.Op == arg {
+ return
+ }
+ if node.Op == imm {
+ return
+ }
+ if node.Right.Op == imm && node.Left.Op == imm {
+ switch node.Op {
+ case min:
+ node.Value = node.Left.Value - node.Right.Value
+ case plus:
+ node.Value = node.Left.Value + node.Right.Value
+ case mul:
+ node.Value = node.Left.Value * node.Right.Value
+ case div:
+ node.Value = node.Left.Value / node.Right.Value
+ }
+ node.Op = imm
+ node.Left = nil
+ node.Right = nil
+ return
+ }
+ if node.Left.Op != arg && node.Left.Op != imm {
+ secondPass(node.Left)
+ }
+ if node.Right.Op != arg && node.Right.Op != imm {
+ secondPass(node.Right)
+ }
+}
+
+func thirdPass(node *AST, variables []rune) {
+ switch node.Op {
+ case arg:
+ number, found := slices.BinarySearch(variables, rune(node.Value))
+ if found {
+ fmt.Printf("AR %d\n", number)
+ }
+ case imm:
+ fmt.Printf("IM %d\n", node.Value)
+ default:
+ switch node.Left.Op {
+ case arg:
+ number, valid := slices.BinarySearch(variables, rune(node.Left.Value))
+ if valid {
+ fmt.Printf("AR %d\n", number)
+ }
+ case imm:
+ fmt.Printf("IM %d\n", node.Left.Value)
+ default:
+ thirdPass(node.Left, variables)
+ }
+ switch node.Right.Op {
+ case arg:
+ fmt.Println("SW")
+ number, valid := slices.BinarySearch(variables, rune(node.Right.Value))
+ if valid {
+ fmt.Printf("AR %d\n", number)
+ }
+ fmt.Println("SW")
+ case imm:
+ fmt.Println("SW")
+ fmt.Printf("IM %d\n", node.Right.Value)
+ fmt.Println("SW")
+ default:
+ fmt.Println("PU")
+ thirdPass(node.Right, variables)
+ fmt.Println("SW")
+ fmt.Println("PO")
+ }
+ switch node.Op {
+ case mul:
+ fmt.Println("MU")
+ case div:
+ fmt.Println("DI")
+ case min:
+ fmt.Println("SU")
+ case plus:
+ fmt.Println("AD")
}
}
- return
}
resultVariables = append(resultVariables, v)
}
}
-
//Cleaning out the program that is getting extracted
variables[1] = strings.Trim(variables[1], " ")
cleanProgram := []rune(variables[1])
for _, v := range cleanProgram {
if v != ' ' {
resultProgram = append(resultProgram, v)
-
}
-
}
-
return resultVariables, resultProgram
}
projects / TinyThreePassCompiler / .git / blobdiff