Second

1 files changed, 96 insertions, 0 deletions

diff --git a/ast.c b/ast.c
new file mode 100644
index 0000000..3d84d97
--- /dev/null
+++ b/ast.c
@@ -0,0 +1,96 @@
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include "ast.h"
+#include "util.h"
+
+
+void ast_free(AST *ast){
+	assert(ast);
+	switch(ast->type){
+		case AST_LIST:
+			assert(ast->l.len>=0);
+			for(int i=0;i<ast->l.len;i++){
+				assert(ast->l.nodes[i]);
+				ast_free(ast->l.nodes[i]);
+			}
+			break;
+
+		case AST_WORD:
+			assert(ast->w.word);
+			free(ast->w.word);
+			break;
+
+		case AST_NUMBER:
+		case AST_SYMBOL:
+			break;
+
+		default:
+			assert(false);
+	}
+	free(ast);
+}
+
+
+AST* ast_copy(const AST *ast){
+	assert(ast);
+	switch(ast->type){
+		case AST_LIST:{
+			assert(ast->l.len>=0);
+			assert(ast->l.nodes);
+			AST **nodes=malloc(ast->l.len,AST*);
+			for(int i=0;i<ast->l.len;i++)nodes[i]=ast_copy(ast->l.nodes[i]);
+			return ast_list(ast->l.len,nodes);
+		}
+
+		case AST_WORD:
+			assert(ast->w.word);
+			return ast_word(copystring(ast->w.word));
+
+		case AST_NUMBER:
+			return ast_number(ast->n.num);
+
+		case AST_SYMBOL:{
+			assert(ast->s.name);
+			AST *sym=ast_symbol(ast->s.name);
+			sym->s.symid=ast->s.symid;
+			return sym;
+		}
+
+		default:
+			assert(false);
+	}
+}
+
+
+AST* ast_list(int len,AST **nodes){
+	assert(len>=0);
+	assert(nodes);
+	AST *ast=malloc(1,AST);
+	ast->l.len=len;
+	ast->l.nodes=malloc(len,AST*);
+	memcpy(ast->l.nodes,nodes,len*sizeof(AST*));
+	return ast;
+}
+
+AST* ast_word(char *word){
+	assert(word);
+	AST *ast=malloc(1,AST);
+	ast->w.word=word;
+	return ast;
+}
+
+AST* ast_number(double num){
+	AST *ast=malloc(1,AST);
+	ast->n.num=num;
+	return ast;
+}
+
+AST* ast_symbol(char *name){
+	assert(name);
+	AST *ast=malloc(1,AST);
+	ast->s.name=name;
+	ast->s.symid=-1;
+	return ast;
+}