c65gm/internal/commands/wend.go

59 lines
1.2 KiB
Go

package commands
import (
"fmt"
"strings"
"c65gm/internal/compiler"
"c65gm/internal/preproc"
"c65gm/internal/utils"
)
// WendCommand handles WEND statements
// Syntax: WEND
// Ends current WHILE loop
type WendCommand struct {
loopLabel string
skipLabel string
}
func (c *WendCommand) WillHandle(line preproc.Line) bool {
params, err := utils.ParseParams(line.Text)
if err != nil || len(params) == 0 {
return false
}
return strings.ToUpper(params[0]) == "WEND"
}
func (c *WendCommand) Interpret(line preproc.Line, ctx *compiler.CompilerContext) error {
params, err := utils.ParseParams(line.Text)
if err != nil {
return err
}
if len(params) != 1 {
return fmt.Errorf("WEND: expected 1 parameter, got %d", len(params))
}
// Pop loop label
var err2 error
c.loopLabel, err2 = ctx.LoopStartStack.Pop()
if err2 != nil {
return fmt.Errorf("WEND: not inside WHILE loop")
}
// Pop skip label
c.skipLabel, err2 = ctx.LoopEndStack.Pop()
if err2 != nil {
return fmt.Errorf("WEND: not inside WHILE loop")
}
return nil
}
func (c *WendCommand) Generate(_ *compiler.CompilerContext) ([]string, error) {
return []string{
fmt.Sprintf("\tjmp %s", c.loopLabel),
c.skipLabel,
}, nil
}