jitters: print: add printer function

src/ast/printer.h

@@ -0,0 +1,8 @@
+#ifndef PRINTER_H
+#define PRINTER_H
+
+#include "ast/ast.h"
+
+void printer_ast(const struct ast_node *ast);
+
+#endif /* !PRINTER_H */

src/local.am

@@ -16,3 +16,4 @@ jitters_LDADD =
 
 include %D%/ast/local.am
 include %D%/parse/local.am
+include %D%/print/local.am

src/print/local.am

@@ -0,0 +1,4 @@
+jitters_SOURCES += \
+    %D%/printer.c \
+    %D%/printer.h \
+    $(NULL)

src/print/printer.c

@@ -0,0 +1,66 @@
+#include "printer.h"
+
+#include <stdio.h>
+
+static void printer_binop(const struct binop_node *bin_op)
+{
+    putchar('(');
+    printer_ast(bin_op->lhs);
+    switch (bin_op->op)
+    {
+    case PLUS:
+        printf(" + ");
+        break;
+    case MINUS:
+        printf(" - ");
+        break;
+    case TIMES:
+        printf(" * ");
+        break;
+    case DIVIDE:
+        printf(" / ");
+        break;
+    default:
+        break;
+    }
+    printer_ast(bin_op->rhs);
+    putchar(')');
+}
+
+static void printer_unop(const struct unop_node *un_op)
+{
+    putchar('(');
+    switch (un_op->op)
+    {
+    case NEGATE:
+        printf("- ");
+    case IDENTITY:
+    default:
+        break;
+    }
+    printer_ast(un_op->rhs);
+    putchar(')');
+}
+
+static void printer_num(int num)
+{
+    printf("%d", num);
+}
+
+void printer_ast(const struct ast_node *ast)
+{
+    switch (ast->kind)
+    {
+    case BINOP:
+        printer_binop(&ast->val.bin_op);
+        break;
+    case UNOP:
+        printer_unop(&ast->val.un_op);
+        break;
+    case NUM:
+        printer_num(ast->val.num);
+        break;
+    default:
+        break;
+    }
+}

src/print/printer.h

@@ -0,0 +1,8 @@
+#ifndef PRINTER_H
+#define PRINTER_H
+
+#include "ast/ast.h"
+
+void printer_ast(const struct ast_node *ast);
+
+#endif /* !PRINTER_H */