From cca4b9fd2a0839a6eb50edc9f09963288b5f0e41 Mon Sep 17 00:00:00 2001
From: Oscar J Rodriguez <jrpc@google.com>
Date: Sat, 18 Mar 2023 02:13:41 -0700
Subject: [PATCH] First past and printer function are totally ready

---
 compiler.go | 68 ++++++++++++++++++++++++++++++++++++++---------------
 go.mod      |  2 ++
 go.sum      |  2 ++
 3 files changed, 53 insertions(+), 19 deletions(-)
 create mode 100644 go.sum

diff --git a/compiler.go b/compiler.go
index 4ad5e55..6cd94fd 100644
--- a/compiler.go
+++ b/compiler.go
@@ -29,14 +29,16 @@ type AST struct {
 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"
+	input := "[ a b ] (a*a) + (b*b)"
 	//value := []rune(input)
 
 	variables, program := extractVariables(input)
 
 	fmt.Println(variables, program)
-	var Tree AST
-	firstPass(program, &Tree)
+	Tree := AST{}
+	firstPass(variables, program, &Tree)
+	fmt.Println(Tree)
+	printer(&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
@@ -47,53 +49,81 @@ func main() {
 
 }
 
+func printer(tree *AST) {
+	switch {
+	case tree.Op == imm:
+		fmt.Print(tree.Value - 48)
+	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(")")
+
+	}
+}
+
 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)
+			//var zeroOp op
+			if node.Op != 2 && node.Op != 3 && node.Op != 4 && node.Op != 5 {
+				node.Left = &AST{Op: arg, Value: int(program[0])}
 				//a := &AST{Op: imm, N: 5
 			} 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)
+
 	}
 	return
 
diff --git a/go.mod b/go.mod
index e73107b..02248a4 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,5 @@
 module TinyThreePassCompiler
 
 go 1.19
+
+require golang.org/x/exp v0.0.0-20230315142452-642cacee5cc0
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..a06f679
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,2 @@
+golang.org/x/exp v0.0.0-20230315142452-642cacee5cc0 h1:pVgRXcIictcr+lBQIFeiwuwtDIs4eL21OuM9nyAADmo=
+golang.org/x/exp v0.0.0-20230315142452-642cacee5cc0/go.mod h1:CxIveKay+FTh1D0yPZemJVgC/95VzuuOLq5Qi4xnoYc=
-- 
2.25.1