From 4750be2da326297830691c54adbab0a5dea14802 Mon Sep 17 00:00:00 2001
From: Jari Vetoniemi <mailroxas@gmail.com>
Date: Fri, 23 Feb 2018 12:54:43 +0200
Subject: wip

---
 src/fspec/ragel/lexer-stack.rl | 153 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 153 insertions(+)
 create mode 100644 src/fspec/ragel/lexer-stack.rl

(limited to 'src/fspec/ragel/lexer-stack.rl')

diff --git a/src/fspec/ragel/lexer-stack.rl b/src/fspec/ragel/lexer-stack.rl
new file mode 100644
index 0000000..940f820
--- /dev/null
+++ b/src/fspec/ragel/lexer-stack.rl
@@ -0,0 +1,153 @@
+#include "lexer-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);
+}
+
+void
+stack_num(struct stack *stack, const uint8_t base)
+{
+   assert(stack);
+   membuf_terminate(&stack->var.buf, (char[]){ 0 }, 1);
+   const char *str = (char*)stack->var.buf.mem.data + stack->var.offset;
+   stack->type = STACK_NUM;
+   stack->num = strtoll(str, NULL, base);
+   varbuf_remove_last(&stack->var);
+}
+
+const struct fspec_mem*
+stack_get_str(const struct stack *stack)
+{
+   stack_check_type(stack, STACK_STR);
+   return &stack->str;
+}
+
+uint64_t
+stack_get_num(const struct stack *stack)
+{
+   stack_check_type(stack, STACK_NUM);
+   return stack->num;
+}
+
+%%{
+   machine fspec_stack;
+
+   action stack_oct {
+      stack_num(&stack, 8);
+   }
+
+   action stack_hex {
+      stack_num(&stack, 16);
+   }
+
+   action stack_dec {
+      stack_num(&stack, 10);
+   }
+
+   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_esc_num {
+      const fspec_num v = stack_get_num(&stack);
+      assert(v <= 255);
+      membuf_append(&stack.var.buf, (uint8_t[]){ v }, sizeof(uint8_t));
+   }
+
+   action store_esc {
+      const struct { const char e, v; } map[] = {
+         { .e = 'a', .v = '\a' },
+         { .e = 'b', .v = '\b' },
+         { .e = 'f', .v = '\f' },
+         { .e = 'n', .v = '\n' },
+         { .e = 'r', .v = '\r' },
+         { .e = 't', .v = '\t' },
+         { .e = 'v', .v = '\v' },
+         { .e = '\\', .v = '\\' },
+         { .e = '\'', .v = '\'' },
+         { .e = '\"', .v = '"' },
+         { .e = 'e', .v = 0x1B },
+      };
+
+      for (size_t i = 0; i < sizeof(map) / sizeof(map[0]); ++i) {
+         if (fc != map[i].e)
+            continue;
+
+         membuf_append(&stack.var.buf, &map[i].v, sizeof(map[i].v));
+         break;
+      }
+   }
+
+   action store {
+      membuf_append(&stack.var.buf, fpc, 1);
+   }
+
+   action begin_num {
+      varbuf_begin(&stack.var);
+   }
+
+   action begin_str {
+      varbuf_reset(&stack.var);
+   }
+
+   # Semantic
+   quote = ['"];
+   esc = [abfnrtv\\'"e];
+   esc_chr = '\\';
+   esc_hex = 'x' <: xdigit{2};
+   hex = '0x' <: xdigit{1,};
+   oct = [0-7]{1,3};
+   dec = [\-+]? <: (([1-9] <: digit*) | '0');
+   name = ((alpha | '_') <: (alnum | '_')*);
+
+   # Stack
+   stack_name = name >begin_str $store %stack_str;
+   stack_hex = hex >begin_num $store %stack_hex;
+   stack_dec = dec >begin_num $store %stack_dec;
+   stack_oct = oct >begin_num $store %stack_oct;
+   stack_esc_hex = esc_hex >begin_num <>*store %stack_hex;
+   stack_esc = esc_chr <: ((stack_esc_hex | stack_oct) %store_esc_num | esc %~store_esc);
+   stack_str = quote <: ((stack_esc? <: print? $store) - zlen)* >begin_str %stack_str :>> quote;
+   stack_num = stack_dec | stack_hex;
+}%%
-- 
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