Creates functions for compounding atoms back into values in the walk module and uses them in subex/main

1 files changed, 79 insertions, 0 deletions

diff --git a/walk/walk.go b/walk/walk.go
index 33e5554..4da8040 100644
--- a/walk/walk.go
+++ b/walk/walk.go
@@ -4,6 +4,7 @@ import (
 	"io"
 	"encoding/json"
 	"fmt"
+	"strings"
 )
 
 type PathSegment interface {}
@@ -377,3 +378,81 @@ func JsonOut(in chan WalkItem) {
 func ConcatData(first []Atom, second []Atom) []Atom {
 	return append(append([]Atom(nil), first...), second...)
 }
+
+func Atomise(in <-chan WalkValue) <-chan Atom {
+	out := make(chan Atom)
+	go func(out chan<- Atom, input <-chan WalkValue) {
+		for value := range input {
+			value.Pieces(out)
+		}
+		close(out)
+	}(out, in)
+	return out
+}
+
+func Compound(in <-chan Atom) <-chan WalkValue {
+	out := make(chan WalkValue)
+	go func(out chan<- WalkValue, in <-chan Atom) {
+		for {
+			atom, hasAtom := <-in
+			if !hasAtom {
+				break
+			}
+			switch v := atom.(type) {
+				case TerminalValue:
+					out<-v
+					continue
+				case ValueNull:
+					out<-v
+					continue
+				case ValueBool:
+					out<-v
+					continue
+				case ValueNumber:
+					out<-v
+					continue
+				case rune:
+					panic("Error! Rune output by subex but not in a string")
+				case EndString:
+					panic("Error! subex output an EndString before BeginString")
+				case StartString:
+				default:
+					panic("Unknown atom type")
+			}
+			// Handle string start
+			var builder strings.Builder
+			loop: for {
+				atom, hasAtom := <-in
+				if !hasAtom {
+					panic("Missing EndString")
+				}
+				switch v := atom.(type) {
+					case EndString:
+						break loop
+					case rune:
+						builder.WriteRune(v)
+					default:
+						panic("Invalid atom in string")
+				}
+			}
+			out<-ValueString(builder.String())
+		}
+		close(out)
+	}(out, in)
+	return out
+}
+
+func MemoryCompound(in []Atom) (out []WalkValue) {
+	inChan := make(chan Atom)
+	go func(in []Atom, out chan<- Atom) {
+		for _, atom := range in {
+			out<-atom
+		}
+		close(out)
+	}(in, inChan)
+	outChan := Compound(inChan)
+	for value := range outChan {
+		out = append(out, value)
+	}
+	return out
+}
\ No newline at end of file