Change output subex internals to allow structures

Also add substitute register syntactic sugar

5 files changed, 265 insertions, 21 deletions

diff --git a/main/command.go b/main/command.go
index 1d089ee..3f22821 100644
--- a/main/command.go
+++ b/main/command.go
@@ -84,6 +84,54 @@ func (cmd SubstituteValueCommand) String() string {
 	return "s/.../"
 }
 
+type IsStartCommand struct {}
+func (cmd IsStartCommand) exec(state *ProgramState) {
+	if state.start {
+		state.pc += 2
+	} else {
+		state.pc += 1
+	}
+}
+func (cmd IsStartCommand) String() string {
+	return "a"
+}
+
+type IsPrevStartCommand struct {}
+func (cmd IsPrevStartCommand) exec(state *ProgramState) {
+	if state.prevStart {
+		state.pc += 2
+	} else {
+		state.pc += 1
+	}
+}
+func (cmd IsPrevStartCommand) String() string {
+	return "A"
+}
+
+type IsEndCommand struct {}
+func (cmd IsEndCommand) exec(state *ProgramState) {
+	if state.end {
+		state.pc += 2
+	} else {
+		state.pc += 1
+	}
+}
+func (cmd IsEndCommand) String() string {
+	return "e"
+}
+
+type IsNextEndCommand struct {}
+func (cmd IsNextEndCommand) exec(state *ProgramState) {
+	if state.nextEnd {
+		state.pc += 2
+	} else {
+		state.pc += 1
+	}
+}
+func (cmd IsNextEndCommand) String() string {
+	return "E"
+}
+
 type NoopCommand struct {}
 func (cmd NoopCommand) exec(state *ProgramState) {
 	state.pc++
@@ -112,6 +160,38 @@ func (cmd AppendXRegCommand) String() string {
 	return "X"
 }
 
+type SubstituteToXRegCommand struct {
+	subex subex.Transducer
+}
+func (cmd SubstituteToXRegCommand) exec(state *ProgramState) {
+	newValue, err := runSubex(cmd.subex, state.value)
+	if err {
+		state.pc++
+	} else {
+		state.pc += 2
+		state.xreg = newValue
+	}
+}
+func (cmd SubstituteToXRegCommand) String() string {
+	return "x/.../"
+}
+
+type SubstituteAppendXRegCommand struct {
+	subex subex.Transducer
+}
+func (cmd SubstituteAppendXRegCommand) exec(state *ProgramState) {
+	newValue, err := runSubex(cmd.subex, state.value)
+	if err {
+		state.pc++
+	} else {
+		state.pc += 2
+		state.xreg = append(state.xreg, newValue...)
+	}
+}
+func (cmd SubstituteAppendXRegCommand) String() string {
+	return "X/.../"
+}
+
 type SwapYRegCommand struct {}
 func (cmd SwapYRegCommand) exec(state *ProgramState) {
 	v := state.value
@@ -132,6 +212,38 @@ func (cmd AppendYRegCommand) String() string {
 	return "Y"
 }
 
+type SubstituteToYRegCommand struct {
+	subex subex.Transducer
+}
+func (cmd SubstituteToYRegCommand) exec(state *ProgramState) {
+	newValue, err := runSubex(cmd.subex, state.value)
+	if err {
+		state.pc++
+	} else {
+		state.pc += 2
+		state.yreg = newValue
+	}
+}
+func (cmd SubstituteToYRegCommand) String() string {
+	return "y/.../"
+}
+
+type SubstituteAppendYRegCommand struct {
+	subex subex.Transducer
+}
+func (cmd SubstituteAppendYRegCommand) exec(state *ProgramState) {
+	newValue, err := runSubex(cmd.subex, state.value)
+	if err {
+		state.pc++
+	} else {
+		state.pc += 2
+		state.yreg = append(state.xreg, newValue...)
+	}
+}
+func (cmd SubstituteAppendYRegCommand) String() string {
+	return "Y/.../"
+}
+
 type SwapZRegCommand struct {}
 func (cmd SwapZRegCommand) exec(state *ProgramState) {
 	v := state.value
@@ -152,6 +264,38 @@ func (cmd AppendZRegCommand) String() string {
 	return "Z"
 }
 
+type SubstituteToZRegCommand struct {
+	subex subex.Transducer
+}
+func (cmd SubstituteToZRegCommand) exec(state *ProgramState) {
+	newValue, err := runSubex(cmd.subex, state.value)
+	if err {
+		state.pc++
+	} else {
+		state.pc += 2
+		state.zreg = newValue
+	}
+}
+func (cmd SubstituteToZRegCommand) String() string {
+	return "z/.../"
+}
+
+type SubstituteAppendZRegCommand struct {
+	subex subex.Transducer
+}
+func (cmd SubstituteAppendZRegCommand) exec(state *ProgramState) {
+	newValue, err := runSubex(cmd.subex, state.value)
+	if err {
+		state.pc++
+	} else {
+		state.pc += 2
+		state.zreg = append(state.xreg, newValue...)
+	}
+}
+func (cmd SubstituteAppendZRegCommand) String() string {
+	return "Z/.../"
+}
+
 type JumpCommand struct {
 	destination int
 }
diff --git a/main/lex.go b/main/lex.go
index 496abd0..a28975f 100644
--- a/main/lex.go
+++ b/main/lex.go
@@ -171,21 +171,28 @@ func lexCommand(l *lexer) stateFunc {
 	l.ignore()
 	r := l.next()
 	switch r {
-		case eof:
-			l.emit(TokenEOF)
-			return nil
-		case '{':
-			l.emit(TokenLBrace)
-			return lexCommand
-		case '}':
-			l.emit(TokenRBrace)
-			return lexCommand
-		case 's', 'S':
-			l.emit(TokenCommand)
+	case eof:
+		l.emit(TokenEOF)
+		return nil
+	case '{':
+		l.emit(TokenLBrace)
+		return lexCommand
+	case '}':
+		l.emit(TokenRBrace)
+		return lexCommand
+	case 's', 'S':
+		l.emit(TokenCommand)
+		return lexSubstitution
+	case 'x', 'X', 'y', 'Y', 'z', 'Z':
+		l.emit(TokenCommand)
+		if l.peek() == '/' {
 			return lexSubstitution
-		case ':', 'b':
-			l.emit(TokenCommand)
-			return lexLabel
+		} else {
+			return lexCommand
+		}
+	case ':', 'b':
+		l.emit(TokenCommand)
+		return lexLabel
 	}
 	if isAlpha(r) {
 		l.emit(TokenCommand)
diff --git a/main/main.go b/main/main.go
index 3a864ad..3fb1cbf 100644
--- a/main/main.go
+++ b/main/main.go
@@ -10,6 +10,7 @@ import (
 
 type ProgramState struct {
 	value, xreg, yreg, zreg []walk.Value
+	start, prevStart, end, nextEnd bool
 	in walk.StredReader
 	out walk.StredWriter
 	program []Command
@@ -42,6 +43,10 @@ func run(config config) {
 			break
 		}
 		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)
diff --git a/main/main_test.go b/main/main_test.go
index a7a7795..7aa90aa 100644
--- a/main/main_test.go
+++ b/main/main_test.go
@@ -5,6 +5,8 @@ import (
 	"testing"
 )
 
+var miscInput string = `{"something":{"nested":"Here is my test value"},"array":["Hello","world","these","are","values"],"people":[{"first_name":"Charlie","last_name":"Johnson","age":22},{"first_name":"Tom","last_name":"Johnson","age":18},{"first_name":"Charlie","last_name":"Chaplin","age":122},{"first_name":"John","last_name":"Johnson","age":48}]}`
+
 func TestMain(t *testing.T) {
 	type test struct {
 		program string
@@ -17,9 +19,51 @@ func TestMain(t *testing.T) {
 		{
 			program: `s/#(~(people)~$_@(1$_#(~(first_name)~$_.|(..$_){-0})-|(..$_){-0})-|(..$_){-0})-/p`,
 			quiet: true,
-			input: `{"something":{"nested":"Here is my test value"},"array":["Hello","world","these","are","values"],"people":[{"first_name":"Charlie","last_name":"Johnson","age":22},{"first_name":"Tom","last_name":"Johnson","age":18},{"first_name":"Charlie","last_name":"Chaplin","age":122},{"first_name":"John","last_name":"Johnson","age":48}]}`,
+			input: miscInput,
+			expected: `"Tom"`,
+		},
+		{
+			program: `s/#("people"$_ @(1 $_#("first_name"$_ .)-)-)-/p`,
+			quiet: true,
+			input: miscInput,
+			expected: `"Tom"`,
+		},
+		{
+			program: "s/#(\"people\" @(1 #(\"first_name\" (.$a))-)-)-$_ `$a`/p",
+			quiet: true,
+			input: miscInput,
 			expected: `"Tom"`,
 		},
+		{
+			program: "s/#(\"people\" @(2 (.$a))-)-$_ `$a`/p",
+			quiet: true,
+			input: miscInput,
+			expected: `{"first_name":"Charlie","last_name":"Chaplin","age":122}`,
+		},
+		{
+			program: "s/#(\"people\"$_ :(#(\"age\"$_ .)-):)-/p",
+			quiet: true,
+			input: miscInput,
+			expected: `[22,18,122,48]`,
+		},
+		{
+			program: "aX/#(\"people\" :(#()#):)#$_ `1`/o es/#()#/{ xs/.{-0}+/p }",
+			quiet: true,
+			input: miscInput,
+			expected: "4",
+		},
+		{
+			program: "s/#(\"people\"$_ .)-/{ s/:():/p as/:(#()#):/{ xdx } s/:(#((\"first_name\" | \"last_name\") .)#)-/X es/@(.#()-)-/{ xs/(#(\"first_name\" \".{-0}$a\")# | #(\"last_name\" \".{-0}$b\")# | .){-0}$_ `\"$a $b\"`/Xxs/-(..)@/p } }",
+			quiet: true,
+			input: miscInput,
+			expected: `["Charlie Johnson","Tom Johnson","Charlie Chaplin","John Johnson"]`,
+		},
+		{
+			program: "s/#(\"people\"$_ .)-/{ s/:():/p as/:(#()#):/{ xdx } X/:(#((\"first_name\" | \"last_name\") .)#)-/o es/@(.#()-)-/{ xX/(#(\"first_name\" \".{-0}$a\")# | #(\"last_name\" \".{-0}$b\")# | .){-0}$_ `\"$a $b\"`/xs/-(..)@/p } }",
+			quiet: true,
+			input: miscInput,
+			expected: `["Charlie Johnson","Tom Johnson","Charlie Chaplin","John Johnson"]`,
+		},
 	}
 
 	for i, test := range tests {
diff --git a/main/parse.go b/main/parse.go
index 9c7a437..3e0e80b 100644
--- a/main/parse.go
+++ b/main/parse.go
@@ -76,17 +76,61 @@ func (p *parser) parseBasicCommand(commands []Command, commandChar rune) []Comma
 		case 'o':
 			return append(commands, NoopCommand{})
 		case 'x':
-			return append(commands, SwapXRegCommand{})
+			delim := p.peek()
+			if delim.typ != TokenSubstituteDelimiter {
+				return append(commands, SwapXRegCommand{})
+			}
+			ast := p.parseSubex()
+			subex := subex.CompileTransducer(ast)
+			return append(commands, SubstituteToXRegCommand {subex}, JumpCommand {len(commands) + 3})
 		case 'X':
-			return append(commands, AppendXRegCommand{})
+			delim := p.peek()
+			if delim.typ != TokenSubstituteDelimiter {
+				return append(commands, AppendXRegCommand{})
+			}
+			ast := p.parseSubex()
+			subex := subex.CompileTransducer(ast)
+			return append(commands, SubstituteAppendXRegCommand {subex}, JumpCommand {len(commands) + 3})
 		case 'y':
-			return append(commands, SwapYRegCommand{})
+			delim := p.peek()
+			if delim.typ != TokenSubstituteDelimiter {
+				return append(commands, SwapYRegCommand{})
+			}
+			ast := p.parseSubex()
+			subex := subex.CompileTransducer(ast)
+			return append(commands, SubstituteToYRegCommand {subex}, JumpCommand {len(commands) + 3})
 		case 'Y':
-			return append(commands, AppendYRegCommand{})
+			delim := p.peek()
+			if delim.typ != TokenSubstituteDelimiter {
+				return append(commands, AppendYRegCommand{})
+			}
+			ast := p.parseSubex()
+			subex := subex.CompileTransducer(ast)
+			return append(commands, SubstituteAppendYRegCommand {subex}, JumpCommand {len(commands) + 3})
 		case 'z':
-			return append(commands, SwapZRegCommand{})
+			delim := p.peek()
+			if delim.typ != TokenSubstituteDelimiter {
+				return append(commands, SwapZRegCommand{})
+			}
+			ast := p.parseSubex()
+			subex := subex.CompileTransducer(ast)
+			return append(commands, SubstituteToZRegCommand {subex}, JumpCommand {len(commands) + 3})
 		case 'Z':
-			return append(commands, AppendZRegCommand{})
+			delim := p.peek()
+			if delim.typ != TokenSubstituteDelimiter {
+				return append(commands, AppendZRegCommand{})
+			}
+			ast := p.parseSubex()
+			subex := subex.CompileTransducer(ast)
+			return append(commands, SubstituteAppendZRegCommand {subex}, JumpCommand {len(commands) + 3})
+		case 'a':
+			return append(commands, IsStartCommand{}, JumpCommand {len(commands) + 3})
+		case 'A':
+			return append(commands, IsPrevStartCommand{}, JumpCommand {len(commands) + 3})
+		case 'e':
+			return append(commands, IsEndCommand{}, JumpCommand {len(commands) + 3})
+		case 'E':
+			return append(commands, IsNextEndCommand{}, JumpCommand {len(commands) + 3})
 		case ':':
 			labelToken := p.next()
 			if labelToken.typ != TokenLabel {