7101 - tile: remove quotes when evaluating strings

This found several bugs due to me not checking for null strings.

108write.subx

@@ -25,6 +25,9 @@ write:  # f: fd or (addr stream byte), s: (addr array byte)
     # . prologue
     55/push-ebp
     89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # if (s == 0) return
+    81          7/subop/compare     1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       0/imm32           # compare *(ebp+12)
+    74/jump-if-=  $write:end/disp8
     # if (f < 0x08000000) _write(f, s) and return  # f can't be a user-mode address, so treat it as a kernel file descriptor
     81          7/subop/compare     1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         0x08000000/imm32  # compare *(ebp+8)
     73/jump-if-addr>=  $write:fake/disp8

310copy-bytes.subx

@@ -113,3 +113,44 @@ test-stream-to-string:
     89/<- %esp 5/r32/ebp
     5d/pop-to-ebp
     c3/return
+
+# like stream-to-string but ignore surrounding quotes
+# we might do other stuff here later
+unquote-stream-to-string:  # in: (addr stream _), out: (addr handle array _)
+    # . prologue
+    55/push-ebp
+    89/<- %ebp 4/r32/esp
+    # . save registers
+    50/push-eax
+    51/push-ecx
+    52/push-edx
+    56/push-esi
+    # esi = s
+    8b/-> *(ebp+8) 6/r32/esi
+    # var len/ecx: int = s->write - s->read - 2
+    8b/-> *esi 1/r32/ecx
+    2b/subtract *(esi+4) 1/r32/ecx
+    81 7/subop/compare %ecx 2/imm32
+    7c/jump-if-< $unquote-stream-to-string:end/disp8
+    81 5/subop/subtract %ecx 2/imm32
+    # allocate
+    (allocate-array Heap %ecx *(ebp+0xc))
+    # var in/edx: (addr byte) = s->data + s->read + 1
+    8b/-> *(esi+4) 2/r32/edx
+    8d/copy-address *(esi+edx+0xd) 2/r32/edx  # Stream-data + 1
+    # var dest/eax: (addr byte) = data for out
+    8b/-> *(ebp+0xc) 0/r32/eax
+    (lookup *eax *(eax+4))  # => eax
+    8d/copy-address *(eax+4) 0/r32/eax
+    #
+    (copy-bytes %edx %eax %ecx)
+$unquote-stream-to-string:end:
+    # . restore registers
+    5e/pop-to-esi
+    5a/pop-to-edx
+    59/pop-to-ecx
+    58/pop-to-eax
+    # . epilogue
+    89/<- %esp 5/r32/ebp
+    5d/pop-to-ebp
+    c3/return

400.mu

@@ -177,6 +177,7 @@ sig new-buffered-file out: (addr handle buffered-file)
 sig stream-empty? s: (addr stream _) -> result/eax: boolean
 sig stream-full? s: (addr stream _) -> result/eax: boolean
 sig stream-to-string in: (addr stream _), out: (addr handle array _)
+sig unquote-stream-to-string in: (addr stream _), out: (addr handle array _)
 sig stream-first s: (addr stream byte) -> result/eax: byte
 sig stream-final s: (addr stream byte) -> result/eax: byte
 

apps/tile/main.mu

@@ -77,12 +77,7 @@ fn test {
   initialize-environment-with-fake-screen env, 5, 0xa
   var g/eax: grapheme <- copy 0x22  # '"'
   process env, g
-  g <- copy 0x31  # '1'
-  process env, g
-  g <- copy 0x20  # space
-  process env, g
-  g <- copy 0x33  # '3'
-  process env, g
+  render env
 }
 
 fn repl {

apps/tile/rpn.mu

@@ -109,7 +109,7 @@ fn evaluate functions: (addr handle function), bindings: (addr table), scratch:
         break-if-!=
         var h: (handle array byte)
         var s/eax: (addr handle array byte) <- address h
-        stream-to-string curr-stream, s  # leak
+        unquote-stream-to-string curr-stream, s  # leak
         push-string-to-value-stack out, *s
         break $evaluate:process-word
       }

apps/tile/value-stack.mu

@@ -130,6 +130,8 @@ fn value-stack-max-width _self: (addr value-stack) -> result/eax: int {
       break-if-!=
       var s-ah/eax: (addr handle array byte) <- get g, text-data
       var s/eax: (addr array byte) <- lookup *s-ah
+      compare s, 0
+      break-if-=
       var w/eax: int <- length s
       compare w, out
       break-if-<=