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greater.go
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greater.go
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package ast
import (
"fmt"
"github.com/NicoNex/tau/internal/code"
"github.com/NicoNex/tau/internal/compiler"
"github.com/NicoNex/tau/internal/obj"
)
type Greater struct {
l Node
r Node
pos int
}
func NewGreater(l, r Node, pos int) Node {
return Greater{
l: l,
r: r,
pos: pos,
}
}
func (g Greater) Eval() (obj.Object, error) {
left, err := g.l.Eval()
if err != nil {
return obj.NullObj, err
}
right, err := g.r.Eval()
if err != nil {
return obj.NullObj, err
}
switch {
case obj.AssertTypes(left, obj.IntType) && obj.AssertTypes(right, obj.IntType):
return obj.ParseBool(int64(left.(obj.Integer)) > int64(right.(obj.Integer))), nil
case obj.AssertTypes(left, obj.IntType, obj.FloatType) && obj.AssertTypes(right, obj.IntType, obj.FloatType):
l, r := obj.ToFloat(left, right)
return obj.ParseBool(float64(l.(obj.Float)) > float64(r.(obj.Float))), nil
case obj.AssertTypes(left, obj.StringType) && obj.AssertTypes(right, obj.StringType):
return obj.ParseBool(left.String() > right.String()), nil
default:
return obj.NullObj, fmt.Errorf("unsupported operator '>' for types %v and %v", left.Type(), right.Type())
}
}
func (g Greater) String() string {
return fmt.Sprintf("(%v > %v)", g.l, g.r)
}
func (g Greater) Compile(c *compiler.Compiler) (position int, err error) {
if g.IsConstExpression() {
o, err := g.Eval()
if err != nil {
return 0, c.NewError(g.pos, err.Error())
}
position = c.Emit(code.OpConstant, c.AddConstant(o))
c.Bookmark(g.pos)
return position, err
}
if position, err = g.l.Compile(c); err != nil {
return
}
if position, err = g.r.Compile(c); err != nil {
return
}
position = c.Emit(code.OpGreaterThan)
c.Bookmark(g.pos)
return
}
func (g Greater) IsConstExpression() bool {
return g.l.IsConstExpression() && g.r.IsConstExpression()
}