Upgrades the substitute command to also act as a filter

Substitute now captures the command after it and only runs it if the substitution is a success

1 files changed, 12 insertions, 1 deletions

diff --git a/main/parse.go b/main/parse.go
index bf2f0ac..aed87cc 100644
--- a/main/parse.go
+++ b/main/parse.go
@@ -234,7 +234,18 @@ func (p *parser) parseBasicCommand(commandChar rune) Command {
 			return AppendNextCommand{}
 		case 's':
 			subex := p.parseSubex()
-			return SubstituteCommand {subex: subex}
+			var next Command
+			token := p.peek()
+			switch token.typ {
+				case TokenEOF, TokenRBrace:
+					next = NoopCommand{}
+				default:
+					next = p.parseCommand()
+			}
+			return SubstituteCommand {
+				subex: subex,
+				next: next,
+			}
 		case 'i':
 			items := p.parseLiterals()
 			return PrintLiteralsCommand {items: items}