From 9a20ef543b1ff7fd0eb598d55953ee7e26ee2b67 Mon Sep 17 00:00:00 2001
From: Benjamin Vedder <benjamin@vedder.se>
Date: Sun, 6 Mar 2022 20:14:10 +0100
Subject: [PATCH] Squashed 'lispBM/lispBM/' changes from 9b375671..e81f234f

e81f234f create_ctx changes to when it invokes gc to free up enough space for a context
55d7617d a first go at some escape characters. newline and backslash so far

git-subtree-dir: lispBM/lispBM
git-subtree-split: e81f234fdcac5728ef04ae9144e3aa7ed55306fa
---
 src/eval_cps.c | 26 ++++++++++++++------------
 src/tokpar.c   | 18 +++++++++++++++++-
 2 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/src/eval_cps.c b/src/eval_cps.c
index 24ea16fd..5960dba5 100644
--- a/src/eval_cps.c
+++ b/src/eval_cps.c
@@ -701,16 +701,21 @@ lbm_cid lbm_create_ctx(lbm_value program, lbm_value env, uint32_t stack_size) {
 
   if (lbm_type_of(program) != LBM_PTR_TYPE_CONS) return -1;
 
-  if (lbm_memory_num_free() < stack_size + (sizeof(eval_context_t)/4) ) {
-    gc(NIL, NIL);
-  }
-  if (lbm_memory_num_free() < stack_size + (sizeof(eval_context_t)/4) ) {
-    return -1;
-  }
-
   eval_context_t *ctx = NULL;
   ctx = (eval_context_t*)lbm_memory_allocate(sizeof(eval_context_t) / 4);
-  if (ctx == NULL) return -1; // no more contexts possible!
+  if (ctx == NULL) {
+    gc(program,env);
+    ctx = (eval_context_t*)lbm_memory_allocate(sizeof(eval_context_t) / 4);
+  }
+  if (ctx == NULL) return -1;
+
+  if (!lbm_stack_allocate(&ctx->K, stack_size)) {
+    gc(program,env);
+    if (!lbm_stack_allocate(&ctx->K, stack_size)) {
+      lbm_memory_free((uint32_t*)ctx);
+      return -1;
+    }
+  }
 
   lbm_int cid = lbm_memory_address_to_ix((uint32_t*)ctx);
 
@@ -727,10 +732,7 @@ lbm_cid lbm_create_ctx(lbm_value program, lbm_value env, uint32_t stack_size) {
   ctx->next = NULL;
 
   ctx->id = cid;
-  if (!lbm_stack_allocate(&ctx->K, stack_size)) {
-    lbm_memory_free((uint32_t*)ctx);
-    return -1;
-  }
+
   if (!lbm_push_u32(&ctx->K, lbm_enc_u(DONE))) {
     lbm_stack_free(&ctx->K);
     lbm_memory_free((uint32_t*)ctx);
diff --git a/src/tokpar.c b/src/tokpar.c
index a9962051..f8d73dcc 100644
--- a/src/tokpar.c
+++ b/src/tokpar.c
@@ -194,6 +194,14 @@ int tok_symbol(lbm_tokenizer_char_stream_t *str) {
   return (int)n;
 }
 
+static char translate_escape_char(char c) {
+  switch(c) {
+  case '\\': return '\\';
+  case 'n': return '\n';
+  default: return '\\';
+  }
+}
+
 int tok_string(lbm_tokenizer_char_stream_t *str) {
 
   unsigned int i = 0;
@@ -221,7 +229,15 @@ int tok_string(lbm_tokenizer_char_stream_t *str) {
   clear_sym_str();
 
   for (i = 0; i < len; i ++) {
-    sym_str[i] = get(str);
+    char c = get(str);
+    if (c == '\\') {
+      if (i + 1 < len) {
+        char escaped = get(str);
+        c = translate_escape_char(escaped);
+        len-=1;
+      }
+    }
+    sym_str[i] = c;
     n++;
   }