Simplified ssa package

src/ssa/common.go

@@ -0,0 +1,65 @@
+package ssa
+
+import (
+	"strings"
+
+	"git.urbach.dev/cli/q/src/token"
+)
+
+// Arguments defines a list of values that this value depends on.
+type Arguments []Value
+
+func (v Arguments) Inputs() []Value { return v }
+
+// String returns a comma-separated list of all arguments.
+func (v Arguments) String() string {
+	tmp := strings.Builder{}
+
+	for i, arg := range v {
+		tmp.WriteString(arg.String())
+
+		if i != len(v)-1 {
+			tmp.WriteString(", ")
+		}
+	}
+
+	return tmp.String()
+}
+
+func (a Arguments) Equals(b Arguments) bool {
+	if len(a) != len(b) {
+		return false
+	}
+
+	for i := range a {
+		if !a[i].Equals(b[i]) {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Liveness tracks where the value is used.
+type Liveness struct {
+	users []Value
+}
+
+func (v *Liveness) AddUser(user Value) { v.users = append(v.users, user) }
+func (v *Liveness) Users() []Value     { return v.users }
+
+type HasLiveness interface {
+	AddUser(Value)
+	Users() []Value
+}
+
+// Source tracks the source tokens.
+type Source token.List
+
+func (v Source) Start() token.Position { return v[0].Position }
+func (v Source) End() token.Position   { return v[len(v)-1].End() }
+
+type HasSource interface {
+	Start() token.Position
+	End() token.Position
+}