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package main
import (
"fmt"
"os"
"bufio"
)
type PathSegment interface {}
type Path []PathSegment
type TerminalValue int
const (
ArrayBegin TerminalValue = iota
ArrayEnd
MapBegin
MapEnd
)
type ValueNull struct {}
type ValueBool bool
type ValueNumber float64
type ValueString string
type WalkValue interface {}
type Program []Command
type ProgramState struct {
space WalkItem
in chan WalkItem
out chan WalkItem
program []Command
}
type StringSegmentPathFilterAST struct {
index string
}
func (ast StringSegmentPathFilterAST) compileWith(next PathFilterState) PathFilterState {
return StringSegmentPathFilter {
index: ast.index,
next: next,
}
}
type RepeatPathFilterAST struct {
content PathFilterAST
}
func (ast RepeatPathFilterAST) compileWith(next PathFilterState) PathFilterState {
nextGroup := &GroupPathFilter{}
repeatStart := ast.content.compileWith(nextGroup)
nextGroup.filters = []PathFilterState{next, repeatStart}
return nextGroup
}
type SequencePathFilterAST struct {
sequence []PathFilterAST
}
func (ast SequencePathFilterAST) compileWith(next PathFilterState) PathFilterState {
for i := len(ast.sequence) - 1; i >= 0; i -= 1 {
next = ast.sequence[i].compileWith(next)
}
return next
}
type AnySegmentPathFilterAST struct {}
func (ast AnySegmentPathFilterAST) compileWith(next PathFilterState) PathFilterState {
return AnySegmentPathFilter{next: next}
}
type PathFilterAST interface {
compileWith(PathFilterState) PathFilterState
}
func compilePathFilterAST(ast PathFilterAST) PathFilter {
return PathFilter{
initial: ast.compileWith(NonePathFilter{}),
}
}
func main() {
if len(os.Args) < 2 {
fmt.Println("Missing program arg")
return
}
//input := os.Args[1]
//tokens := Lex(input)
//program := Parse(tokens)
stdin := bufio.NewReader(os.Stdin)
dataStream := Json(stdin)
var allRemainingPathFilter AnySegmentPathFilter
{
g := GroupPathFilter {
filters: []PathFilterState{NonePathFilter{}},
}
allRemainingPathFilter = AnySegmentPathFilter {
next: PathFilterState(&g),
}
g.filters = append(g.filters, PathFilterState(&allRemainingPathFilter))
}
state := ProgramState {
in: dataStream,
out: make(chan WalkItem),
program: []Command {
FilteredCommand {
filter: compilePathFilterAST(
StringSegmentPathFilterAST {"people"},
),
command: PrintValueCommand{},
},
FilteredCommand {
filter: compilePathFilterAST(
SequencePathFilterAST {
[]PathFilterAST{
StringSegmentPathFilterAST {"people"},
AnySegmentPathFilterAST{},
StringSegmentPathFilterAST {"age"},
},
},
),
command: PrintValueCommand{},
},
},
}
go func () {
for walkItem := range dataStream {
state.space = walkItem
for _, cmd := range state.program {
cmd.exec(&state)
}
}
close(state.out)
}()
JsonOut(state.out)
}
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