<- Back to shtanton's homepage
aboutsummaryrefslogtreecommitdiff
path: root/main/command.go
blob: ea6fb59a4cd9fdc9fa749b92273d66bec1eb6125 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
package main

import (
	"main/walk"
	"main/subex"
)

type PrintValueCommand struct {}
func (cmd PrintValueCommand) exec(state *ProgramState) {
	path := walk.PathFromWalkValues(state.path)
	for _, value := range state.value {
		state.out <- walk.WalkItem {
			Value: value,
			Path: path,
		}
	}
}

type ToggleTerminalCommand struct {}
func (cmd ToggleTerminalCommand) exec(state *ProgramState) {
	toggled := map[walk.TerminalValue]walk.TerminalValue {
		walk.ArrayBegin: walk.MapBegin,
		walk.ArrayEnd: walk.MapEnd,
		walk.MapBegin: walk.ArrayBegin,
		walk.MapEnd: walk.ArrayEnd,
	}

	for i := range state.value {
		terminal, isTerminal := state.value[i].(walk.TerminalValue)
		if !isTerminal {
			continue
		}
		state.value[i] = toggled[terminal]
	}
}

type FilteredCommand struct {
	filter Filter
	command Command
}
func (cmd FilteredCommand) exec(state *ProgramState) {
	path := walk.PathFromWalkValues(state.path)
	for _, value := range state.value {
		if cmd.filter.exec(walk.WalkItem {
			Value: value,
			Path: path,
		}) {
			cmd.command.exec(state)
			return
		}
	}
}

type SequenceCommand struct {
	commands []Command
}
func (cmd SequenceCommand) exec(state *ProgramState) {
	for _, command := range cmd.commands {
		command.exec(state)
	}
}

type AppendLiteralCommand struct {
	values []walk.WalkValue
}
func (cmd AppendLiteralCommand) exec(state *ProgramState) {
	state.value = append(state.value, cmd.values...)
}

type PrependLiteralCommand struct {
	values []walk.WalkValue
}
func (cmd PrependLiteralCommand) exec(state *ProgramState) {
	var newItems []walk.WalkValue
	newItems = append(newItems, cmd.values...)
	state.value = append(newItems, state.value...)
}

type NextCommand struct {}
func (cmd NextCommand) exec(state *ProgramState) {
	nextItem := <- state.in
	state.value = []walk.WalkValue{nextItem.Value}
	state.path = nextItem.Path.ToWalkValues()
}

type AppendNextCommand struct {}
func (cmd AppendNextCommand) exec(state *ProgramState) {
	nextItem := <- state.in
	state.value = append(state.value, nextItem.Value)
	state.path = nextItem.Path.ToWalkValues()
}

type PrintLiteralsCommand struct {
	items []walk.WalkItem
}
func (cmd PrintLiteralsCommand) exec(state *ProgramState) {
	for _, item := range cmd.items {
		state.out <- item
	}
}

type DeleteAllCommand struct {}
func (cmd DeleteAllCommand) exec(state *ProgramState) {
	state.path = nil
	state.value = nil
}

type SubstituteCommand struct {
	subex subex.SubexState
	next Command
}
func (cmd SubstituteCommand) exec(state *ProgramState) {
	valueStream := make(chan walk.WalkValue)
	go func(in []walk.WalkValue, out chan<- walk.WalkValue) {
		for _, value := range in {
			out <- value
		}
		close(out)
	}(state.value, valueStream)
	atomStream := walk.Atomise(valueStream)
	atomsOut, error := subex.RunTransducer(cmd.subex, atomStream)
	if error {
		return
	}
	valuesOut, err := walk.MemoryCompound(atomsOut)
	if err != nil {
		return
	}
	state.value = valuesOut
	cmd.next.exec(state)
}

type Command interface {
	exec(*ProgramState)
}

type NoopCommand struct {}
func (cmd NoopCommand) exec(state *ProgramState) {}