add echo flag for use when consuming files

README.md

@@ -170,11 +170,11 @@ Done:
 - [x] Document parenthesis syntax
 - [x] Specify number of samples as a command line option
 - [x] Figure out how to make models executable, by adding a #!/bin/bash-style command at the top?
+- [x] Make -n flag work
+- [x] Add flag to repeat input lines (useful when reading from files)
 
 To (possibly) do:
 
-- [ ] Add flag to repeat input lines (useful when reading from files)
-- [ ] Make -n flag work
 - [ ] Add functions. Now easier to do with an explicit representation of the stakc
 - [ ] Think about how to draw a histogram from samples
 - [ ] Dump samples to file

fermi.go

@@ -356,10 +356,13 @@ func parseWordsIntoOpAndDist(words []string, vars map[string]Dist) (string, Dist
 // We want this as a function (rather than just be in main)
 // to be able to have parenthesis/recusion, possibly functions
 
-func runRepl(stack Stack, reader *bufio.Reader) Stack {
+func runRepl(stack Stack, reader *bufio.Reader, echo_flag *bool) Stack {
 replForLoop:
 	for {
 		new_line, _ := reader.ReadString('\n')
+		if *echo_flag {
+			fmt.Printf(new_line)
+		}
 		new_line_before_comments, _, _ := strings.Cut(new_line, "#")
 		new_line_trimmed := strings.TrimSpace(new_line_before_comments)
 		words := strings.Split(new_line_trimmed, " ")
@@ -369,7 +372,7 @@ replForLoop:
 			continue replForLoop
 		/* Parenthesis */
 		case len(words) == 2 && (words[0] == "*" || words[0] == "+" || words[0] == "-" || words[0] == "/") && words[1] == "(":
-			new_stack := runRepl(Stack{old_dist: INIT_DIST, vars: stack.vars}, reader)
+			new_stack := runRepl(Stack{old_dist: INIT_DIST, vars: stack.vars}, reader, echo_flag)
 			combined_dist, err := operateDists(stack.old_dist, new_stack.old_dist, words[0])
 			if err == nil {
 				stack.old_dist = combined_dist
@@ -412,6 +415,7 @@ replForLoop:
 func main() {
 	num_samples_flag := flag.Int("n", N_SAMPLES, "Specifies the number of samples to draw when using samples")
 	filename := flag.String("f", "", "Specifies a file with a model to run")
+	echo_flag := flag.Bool("echo", false, "Specifies whether inputs should be echoed back. Useful if reading from a file.")
 	flag.Parse()
 	N_SAMPLES = *num_samples_flag
 
@@ -428,6 +432,6 @@ func main() {
 		reader = bufio.NewReader(os.Stdin)
 	}
 	stack := Stack{old_dist: INIT_DIST, vars: make(map[string]Dist)}
-	runRepl(stack, reader)
+	runRepl(stack, reader, echo_flag)
 
 }