From 2d3900728fdc556b44713b38d6bea059332f2274 Mon Sep 17 00:00:00 2001
From: Jonas Franz <info@jonasfranz.software>
Date: Mon, 18 May 2020 20:43:36 +0200
Subject: [PATCH] Read line number from file

---
 example.hal              |  0
 hal/module.go            |  2 +-
 parser/program_parser.go | 20 +++++++++++++-------
 3 files changed, 14 insertions(+), 8 deletions(-)
 create mode 100644 example.hal

diff --git a/example.hal b/example.hal
new file mode 100644
index 0000000..e69de29
diff --git a/hal/module.go b/hal/module.go
index e483900..05b6b50 100644
--- a/hal/module.go
+++ b/hal/module.go
@@ -2,7 +2,7 @@ package hal
 
 import "fmt"
 
-type Program []*ProgrammedInstruction
+type Program map[int64]*ProgrammedInstruction
 
 type Module struct {
 	Accumulator    float64
diff --git a/parser/program_parser.go b/parser/program_parser.go
index 861c43e..0026c58 100644
--- a/parser/program_parser.go
+++ b/parser/program_parser.go
@@ -10,10 +10,17 @@ import (
 
 // ParseProgram parses an program by the following specification: LINE_NUMBER INSTRUCTION OPERAND(optional)
 func ParseProgram(input []string) (hal.Program, error) {
-	program := make(hal.Program, len(input))
-	var err error
+	program := make(hal.Program)
 	for index, line := range input {
-		program[index], err = parseInstruction(line)
+		args := strings.Split(line, " ")
+		if len(args) == 0 {
+			continue
+		}
+		lineNumber, err := strconv.ParseInt(args[0], 10, 64)
+		if err != nil {
+			return nil, fmt.Errorf("invalid line number at file line %d: %s", index, args[0])
+		}
+		program[lineNumber], err = parseInstruction(args[1:])
 		if err != nil {
 			return nil, fmt.Errorf("error while parsing line %d: %v", index+1, err)
 		}
@@ -21,10 +28,9 @@ func ParseProgram(input []string) (hal.Program, error) {
 	return program, nil
 }
 
-func parseInstruction(input string) (*hal.ProgrammedInstruction, error) {
-	args := strings.Split(input, " ")
+func parseInstruction(args []string) (*hal.ProgrammedInstruction, error) {
 	if len(args) != 0 && len(args) != 1 {
-		return nil, fmt.Errorf("malformated instruction '%s'", input)
+		return nil, fmt.Errorf("invalid instruction args count (count = %d)", len(args))
 	}
 	instruction := hal.FindInstructionByName(args[0])
 	if instruction == nil {
@@ -36,7 +42,7 @@ func parseInstruction(input string) (*hal.ProgrammedInstruction, error) {
 	if len(args) == 1 {
 		operand, err := strconv.ParseFloat(args[1], 64)
 		if err != nil {
-			return nil, fmt.Errorf("error while parsing operand for instruction '%s': %v", input, err)
+			return nil, fmt.Errorf("error while parsing operand for instruction '%s': %v", args[0], err)
 		}
 		if instruction.ExecuteWithOperand == nil {
 			return nil, fmt.Errorf("instruction '%s' has no operand, got operand %d", instruction.Name, operand)