Added canonical sexps sans parsing

csexp/gen/gen.go

@@ -0,0 +1,36 @@
+package gen
+
+import (
+	"git.codemonkeysoftware.net/b/peachy-go/csexp"
+	"pgregory.net/rapid"
+)
+
+type T rapid.TB
+
+func Atom() *rapid.Generator[csexp.Atom] {
+	return rapid.Custom(func(t *rapid.T) csexp.Atom {
+		return csexp.Atom(rapid.SliceOf(rapid.Byte()).Draw(t, "atom"))
+	})
+}
+
+func List() *rapid.Generator[csexp.List] {
+	return rapid.Custom(func(t *rapid.T) csexp.List {
+		var s []csexp.Sexp = rapid.SliceOfN(rapid.Deferred(Sexp), 0, 5).Draw(t, "s")
+		return csexp.List(s)
+	})
+}
+
+func AsSexp[T csexp.Sexp](value T) csexp.Sexp {
+	return csexp.Sexp(value)
+}
+
+func Sexp() *rapid.Generator[csexp.Sexp] {
+	return rapid.Custom(func(t *rapid.T) csexp.Sexp {
+		choice := rapid.Uint8Range(0, 10).Draw(t, "choice")
+		// If we don't weight it enough towards atoms, it likes to overflow the stack.
+		if choice < 7 {
+			return rapid.Map(Atom(), AsSexp).Draw(t, "atom-sexp")
+		}
+		return rapid.Map(rapid.Deferred(List), AsSexp).Draw(t, "list-sexp")
+	})
+}