Simplified expression evaluation

src/core/EvaluateToken.go

@@ -0,0 +1,100 @@
+package core
+
+import (
+	"encoding/binary"
+
+	"git.urbach.dev/cli/q/src/asm"
+	"git.urbach.dev/cli/q/src/errors"
+	"git.urbach.dev/cli/q/src/eval"
+	"git.urbach.dev/cli/q/src/token"
+	"git.urbach.dev/cli/q/src/types"
+)
+
+// EvaluateToken evaluates a single token.
+func (f *Function) EvaluateToken(t token.Token) (eval.Value, error) {
+	switch t.Kind {
+	case token.Identifier:
+		name := t.Text(f.File.Bytes)
+
+		if name == "true" {
+			value := eval.Number{
+				Typ:    types.Bool,
+				Number: 1,
+			}
+
+			return value, nil
+		}
+
+		if name == "false" {
+			value := eval.Number{
+				Typ:    types.Bool,
+				Number: 0,
+			}
+
+			return value, nil
+		}
+
+		variable, function := f.Identifier(name)
+
+		if variable != nil {
+			f.UseVariable(variable)
+
+			if variable.Value.Alive == 0 {
+				return variable.Value, nil
+			}
+
+			tmp := f.NewRegister()
+			f.RegisterRegister(asm.MOVE, tmp, variable.Value.Register)
+
+			value := eval.Register{
+				Typ:      variable.Value.Typ,
+				Register: tmp,
+			}
+
+			return value, nil
+		}
+
+		if function != nil {
+			value := eval.Label{
+				Typ:   types.AnyPointer,
+				Label: function.UniqueName,
+			}
+
+			return value, nil
+		}
+
+		return nil, errors.New(&errors.UnknownIdentifier{Name: name}, f.File, t.Position)
+
+	case token.Number, token.Rune:
+		number, err := f.ToNumber(t)
+
+		if err != nil {
+			return nil, err
+		}
+
+		value := eval.Number{
+			Typ:    types.AnyInt,
+			Number: number,
+		}
+
+		return value, nil
+
+	case token.String:
+		data := t.Bytes(f.File.Bytes)
+		data = String(data)
+
+		slice := make([]byte, len(data)+8+1)
+		binary.LittleEndian.PutUint64(slice, uint64(len(data)))
+		copy(slice[8:], data)
+		label := f.AddBytes(slice)
+
+		value := eval.Label{
+			Typ:   types.String,
+			Label: label,
+		}
+
+		return value, nil
+	}
+
+	return nil, errors.New(errors.InvalidExpression, f.File, t.Position)
+}