From f54e7e8c2aeb4fafebf0d5bd5570b060462c9ecf Mon Sep 17 00:00:00 2001
From: Jari Vetoniemi <mailroxas@gmail.com>
Date: Thu, 1 Feb 2018 08:31:01 +0200
Subject: Initial commit

---
 src/escpos/stack.rl | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100644 src/escpos/stack.rl

(limited to 'src/escpos/stack.rl')

diff --git a/src/escpos/stack.rl b/src/escpos/stack.rl
new file mode 100644
index 0000000..a051318
--- /dev/null
+++ b/src/escpos/stack.rl
@@ -0,0 +1,92 @@
+#include "stack.h"
+#include <stdlib.h>
+#include <assert.h>
+#include <err.h>
+
+void
+varbuf_begin(struct varbuf *var)
+{
+   assert(var);
+   var->offset = var->buf.written;
+   assert(var->offset <= var->buf.mem.len);
+}
+
+void
+varbuf_reset(struct varbuf *var)
+{
+   assert(var);
+   var->offset = var->buf.written = 0;
+}
+
+void
+varbuf_remove_last(struct varbuf *var)
+{
+   assert(var);
+   assert(var->buf.written >= var->offset);
+   const size_t size = var->buf.written - var->offset;
+   assert(var->buf.written >= size);
+   var->buf.written -= size;
+   assert(var->buf.written <= var->buf.mem.len);
+}
+
+static void
+stack_check_type(const struct stack *stack, const enum stack_type type)
+{
+   assert(stack);
+
+   if (stack->type == type)
+      return;
+
+   const char *got = (type == STACK_STR ? "str" : "num"), *expected = (stack->type == STACK_STR ? "str" : "num");
+   errx(EXIT_FAILURE, "tried to get '%s' from stack, but the last pushed type was '%s'", got, expected);
+}
+
+const struct escpos_mem*
+stack_get_str(const struct stack *stack)
+{
+   stack_check_type(stack, STACK_STR);
+   return &stack->str;
+}
+
+uint8_t
+stack_get_num(const struct stack *stack)
+{
+   stack_check_type(stack, STACK_NUM);
+   return stack->num;
+}
+
+%%{
+   machine escpos_stack;
+
+   action stack_num {
+      const char *byte = (char*)stack.var.buf.mem.data + stack.var.offset;
+      stack.type = STACK_NUM;
+      stack.num = *byte;
+      varbuf_remove_last(&stack.var);
+   }
+
+   action stack_str {
+      membuf_terminate(&stack.var.buf, (char[]){ 0 }, 1);
+      stack.type = STACK_STR;
+      stack.str = stack.var.buf.mem;
+      stack.str.len = stack.var.buf.written;
+   }
+
+   action store {
+      membuf_append(&stack.var.buf, fpc, 1);
+   }
+
+   action begin_num {
+      varbuf_begin(&stack.var);
+   }
+
+   action begin_str {
+      varbuf_reset(&stack.var);
+   }
+
+   NUL = 0x00;
+   TEXT = 32..127;
+
+   stack_num = -128..127 >begin_num $store %stack_num;
+   stack_str = TEXT* $store >begin_str :>> NUL %stack_str;
+}%%
-- 
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