Initial commit

No parsing yet, but the execution is not bad

Commands:
- Print value
- Toggle terminal (switch between array and map)
- Filter command

Filters:
- Path filter

Path filters are compiled from a regex like AST

1 files changed, 139 insertions, 0 deletions

diff --git a/main/main.go b/main/main.go
new file mode 100644
index 0000000..31e46c6
--- /dev/null
+++ b/main/main.go
@@ -0,0 +1,139 @@
+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)
+}