Completely remove the path space

The new design uses deeply nested values in the value space instead.

3 files changed, 19 insertions, 84 deletions

diff --git a/main/command.go b/main/command.go
index 5a898e2..1d089ee 100644
--- a/main/command.go
+++ b/main/command.go
@@ -13,12 +13,11 @@ type Command interface {
 
 type PrintValueCommand struct {}
 func (cmd PrintValueCommand) exec(state *ProgramState) {
-	err := state.out.Write(walk.WalkItem {
-		Path: state.path,
-		Value: state.value,
-	})
-	if err != nil {
-		panic("Error while outputting")
+	for _, value := range state.value {
+		err := state.out.Write(value)
+		if err != nil {
+			panic("Error while outputting")
+		}
 	}
 	state.pc++
 }
@@ -32,8 +31,7 @@ func (cmd NextCommand) exec(state *ProgramState) {
 	if err != nil {
 		panic("Missing next value")
 	}
-	state.value = nextItem.Value
-	state.path = nextItem.Path
+	state.value = []walk.Value{nextItem.Value}
 	state.pc++
 }
 func (cmd NextCommand) String() string {
@@ -46,8 +44,7 @@ func (cmd AppendNextCommand) exec(state *ProgramState) {
 	if err != nil {
 		panic("Missing next value")
 	}
-	state.value = append(state.value, nextItem.Value...)
-	state.path = nextItem.Path
+	state.value = append(state.value, nextItem.Value)
 	state.pc++
 }
 func (cmd AppendNextCommand) String() string {
@@ -63,16 +60,7 @@ func (cmd DeleteValueCommand) String() string {
 	return "d"
 }
 
-type DeletePathCommand struct {}
-func (cmd DeletePathCommand) exec(state *ProgramState) {
-	state.path = nil
-	state.pc++
-}
-func (cmd DeletePathCommand) String() string {
-	return "D"
-}
-
-func runSubex(state subex.Transducer, in walk.ValueList) (walk.ValueList, bool) {
+func runSubex(state subex.Transducer, in []walk.Value) ([]walk.Value, bool) {
 	out, error := subex.RunTransducer(state, in)
 	if error {
 		return nil, true
@@ -96,22 +84,6 @@ func (cmd SubstituteValueCommand) String() string {
 	return "s/.../"
 }
 
-type SubstitutePathCommand struct {
-	subex subex.Transducer
-}
-func (cmd SubstitutePathCommand) exec(state *ProgramState) {
-	newPath, err := runSubex(cmd.subex, state.path)
-	if err {
-		state.pc++
-	} else {
-		state.pc += 2
-		state.path = newPath
-	}
-}
-func (cmd SubstitutePathCommand) String() string {
-	return "S/.../"
-}
-
 type NoopCommand struct {}
 func (cmd NoopCommand) exec(state *ProgramState) {
 	state.pc++
@@ -180,26 +152,6 @@ func (cmd AppendZRegCommand) String() string {
 	return "Z"
 }
 
-type SwapPathCommand struct {}
-func (cmd SwapPathCommand) exec(state *ProgramState) {
-	v := state.value
-	state.value = state.path
-	state.path = v
-	state.pc++
-}
-func (cmd SwapPathCommand) String() string {
-	return "k"
-}
-
-type AppendPathCommand struct {}
-func (cmd AppendPathCommand) exec(state *ProgramState) {
-	state.path = append(state.path, state.value...)
-	state.pc++
-}
-func (cmd AppendPathCommand) String() string {
-	return "K"
-}
-
 type JumpCommand struct {
 	destination int
 }
@@ -220,4 +172,4 @@ func (cmd BranchPlaceholderCommand) exec(state *ProgramState) {
 }
 func (cmd BranchPlaceholderCommand) String() string {
 	return fmt.Sprintf("b%c", cmd.label)
-}
\ No newline at end of file
+}
diff --git a/main/main.go b/main/main.go
index 8e8c369..b7ef568 100644
--- a/main/main.go
+++ b/main/main.go
@@ -7,10 +7,8 @@ import (
 	"main/json"
 )
 
-type Program []Command
-
 type ProgramState struct {
-	path, value, xreg, yreg, zreg walk.ValueList
+	value, xreg, yreg, zreg []walk.Value
 	in walk.StredReader
 	out walk.StredWriter
 	program []Command
@@ -55,23 +53,21 @@ func main() {
 		if err != nil {
 			break
 		}
-		state.value = walkItem.Value
-		state.path = walkItem.Path
+		state.value = []walk.Value{walkItem.Value}
 		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")
+			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
+}
diff --git a/main/parse.go b/main/parse.go
index 141ae7e..9c7a437 100644
--- a/main/parse.go
+++ b/main/parse.go
@@ -65,23 +65,14 @@ func (p *parser) parseBasicCommand(commands []Command, commandChar rune) []Comma
 			return append(commands, PrintValueCommand{})
 		case 'd':
 			return append(commands, DeleteValueCommand{})
-		case 'D':
-			return append(commands, DeletePathCommand{})
 		case 'n':
 			return append(commands, NextCommand{})
 		case 'N':
 			return append(commands, AppendNextCommand{})
-		case 's', 'S':
+		case 's':
 			ast := p.parseSubex()
 			subex := subex.CompileTransducer(ast)
-			switch commandChar {
-				case 's':
-					return append(commands, SubstituteValueCommand {subex}, JumpCommand {len(commands) + 3})
-				case 'S':
-					return append(commands, SubstitutePathCommand {subex}, JumpCommand {len(commands) + 3})
-				default:
-					panic("Unreachable!?!?")
-			}
+			return append(commands, SubstituteValueCommand {subex}, JumpCommand {len(commands) + 3})
 		case 'o':
 			return append(commands, NoopCommand{})
 		case 'x':
@@ -96,10 +87,6 @@ func (p *parser) parseBasicCommand(commands []Command, commandChar rune) []Comma
 			return append(commands, SwapZRegCommand{})
 		case 'Z':
 			return append(commands, AppendZRegCommand{})
-		case 'k':
-			return append(commands, SwapPathCommand{})
-		case 'K':
-			return append(commands, AppendPathCommand{})
 		case ':':
 			labelToken := p.next()
 			if labelToken.typ != TokenLabel {