diff options
Diffstat (limited to 'compiler/ast.go')
| -rw-r--r-- | compiler/ast.go | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/compiler/ast.go b/compiler/ast.go index e9c1b50..803d5a9 100644 --- a/compiler/ast.go +++ b/compiler/ast.go @@ -331,7 +331,7 @@ func newRepeatOneOrMoreNode(left astNode) *concatNode { return newConcatNode( left, &repeatNode{ - left: left, + left: copyAST(left), }) } @@ -369,6 +369,24 @@ func (n *optionNode) last() symbolPositionSet { return s } +func copyAST(src astNode) astNode { + switch n := src.(type) { + case *symbolNode: + return newRangeSymbolNode(n.from, n.to) + case *endMarkerNode: + return newEndMarkerNode(n.id) + case *concatNode: + return newConcatNode(copyAST(n.left), copyAST(n.right)) + case *altNode: + return newAltNode(copyAST(n.left), copyAST(n.right)) + case *repeatNode: + return newRepeatNode(copyAST(n.left)) + case *optionNode: + return newOptionNode(copyAST(n.left)) + } + panic(fmt.Errorf("copyAST cannot handle %T type; AST: %v", src, src)) +} + type followTable map[symbolPosition]symbolPositionSet func genFollowTable(root astNode) followTable { |