1 files changed, 73 insertions, 38 deletions

diff --git a/main/main.go b/main/main.go
index 8e8c369..bfa1afe 100644
--- a/main/main.go
+++ b/main/main.go
@@ -1,48 +1,53 @@
 package main
 
 import (
-	"os"
 	"bufio"
-	"main/walk"
+	"io"
 	"main/json"
+	"main/walk"
+	"os"
 )
 
-type Program []Command
-
 type ProgramState struct {
-	path, value, xreg, yreg, zreg walk.ValueList
+	value, xreg, yreg, zreg []walk.Value
+	start, prevStart, end, nextEnd bool
+	// TODO: This will only ever have 0 or 1 values, it is a slice out of laziness
+	peekStack []walk.WalkItem
 	in walk.StredReader
 	out walk.StredWriter
 	program []Command
 	pc int
 }
-
-func main() {
-	quiet := false
-	var input string
-	hasInput := false
-	
-	for i := 1; i < len(os.Args); i += 1 {
-		switch os.Args[i] {
-			case "-n":
-				quiet = true
-				continue
-		}
-		if i < len(os.Args) - 1 {
-			panic("Unexpected arguments after program")
-		}
-		input = os.Args[i]
-		hasInput = true
+func (state *ProgramState) Read() (walk.WalkItem, error) {
+	if len(state.peekStack) > 0 {
+		item := state.peekStack[len(state.peekStack) - 1]
+		state.peekStack = state.peekStack[:len(state.peekStack) - 1]
+		return item, nil
 	}
-	if !hasInput {
-		panic("Missing program")
+	return state.in.Read()
+}
+func (state *ProgramState) Peek() (walk.WalkItem, error) {
+	item, err := state.Read()
+	if err != nil {
+		return walk.WalkItem{}, err
 	}
+	state.peekStack = append(state.peekStack, item)
+	return item, nil
+}
+
+type config struct {
+	quiet bool
+	program string
+	in io.Reader
+	out io.Writer
+}
 
-	tokens := Lex(input)
+func run(config config) {
+	tokens := Lex(config.program)
 	program := Parse(tokens)
 
-	stdin := bufio.NewReader(os.Stdin)
-	stdout := bufio.NewWriter(os.Stdout)
+	stdin := bufio.NewReader(config.in)
+	stdout := bufio.NewWriter(config.out)
 
 	state := ProgramState {
 		in: json.NewJSONReader(stdin),
@@ -51,27 +56,57 @@ func main() {
 	}
 
 	for {
-		walkItem, err := state.in.Read()
+		walkItem, err := state.Read()
 		if err != nil {
 			break
 		}
-		state.value = walkItem.Value
-		state.path = walkItem.Path
+		state.value = []walk.Value{walkItem.Value}
+		state.start = walkItem.Start
+		state.prevStart = walkItem.PrevStart
+		state.end = walkItem.End
+		state.nextEnd = walkItem.NextEnd
 		state.pc = 0
 		for state.pc < len(state.program) {
 			state.program[state.pc].exec(&state)
 		}
-		if !quiet {
-			err := state.out.Write(walk.WalkItem {
-				Path: state.path,
-				Value: state.value,
-			})
-			if err != nil {
-				panic("Error while outputting")
+		if !config.quiet {
+			for _, value := range state.value {
+				err := state.out.Write(value)
+				if err != nil {
+					panic("Error while outputting")
+				}
 			}
 		}
 	}
 
 	state.in.AssertDone()
 	state.out.AssertDone()
-}
\ No newline at end of file
+}
+
+func main() {
+	config := config {
+		quiet: false,
+		in: os.Stdin,
+		out: os.Stdout,
+	}
+	hasInput := false
+	
+	for i := 1; i < len(os.Args); i += 1 {
+		switch os.Args[i] {
+			case "-n":
+				config.quiet = true
+				continue
+		}
+		if i < len(os.Args) - 1 {
+			panic("Unexpected arguments after program")
+		}
+		config.program = os.Args[i]
+		hasInput = true
+	}
+	if !hasInput {
+		panic("Missing program")
+	}
+
+	run(config)
+
+}