Add more I/O functions

doc/DRAWL.md

@@ -36,8 +36,6 @@ The DRAWL implementation comes with the following built-in functions:
 - T = True
 - F = False
 - NIL = NULL
-- SPACE = SPACE character on output
-- CR = Carriage Return character on output
 - CSET() = Set constant value
 - CSETQ() = Set constant value
 - DEFINE() = Define function
@@ -173,6 +171,16 @@ The DRAWL implementation comes with the following built-in functions:
 - CHARS() = CHARacter String from integer value
 - ASCII() = ASCII value of first character in string
 
+### I/O functions
+
+- HOME()
+- GOTOXY()
+- KEYPRESSED()
+- READKEY()
+- READ()
+- READFILE()
+- READSTRING()
+
 ### Lo-Res Graphics
 
 - GR() = Turn lo-res graphics mode on/off

src/lisp/drawl.pla

@@ -49,7 +49,6 @@ import sexpr
 
   var exception
   var hook_eval
-  var assoc_list
   byte trace
 
   var fmt_fpint
@@ -101,11 +100,6 @@ def natv_fpfrac(symptr, expr)
   return sym_fpfrac
 end
 
-def natv_clear(symptr, expr)
-  assoc_list = NULL
-  return NULL
-end
-
 def natv_gc(symptr, expr)
   gc
   return new_int(heapavail, 0)
@@ -162,6 +156,28 @@ def natv_printer(symptr, expr)
   return new_int(slot, 0)
 end
 
+def natv_home(symptr, expr)
+  conio:textmode(40) // 40 column text
+  return NULL
+end
+
+def natv_gotoxy(symptr, expr)
+  byte x, y
+
+  x = eval_int16(expr)
+  y = eval_int16(expr=>cdr)
+  conio:gotoxy(x, y)
+  return NULL
+end
+
+def natv_keypressed(symptr, expr)
+    return bool_pred(conio:keypressed())
+end
+
+def natv_readkey(symptr, expr)
+    return new_int(conio:getkey(), 0)
+end
+
 def natv_read(symptr, expr)
   return readfn()
 end
@@ -325,14 +341,17 @@ sym_fpint=>natv             = @natv_fpint
 sym_fpfrac=>natv            = @natv_fpfrac
 sym_fpint=>apval            = new_int(fmt_fpint,  0) ^ NULL_HACK
 sym_fpfrac=>apval           = new_int(fmt_fpfrac, 0) ^ NULL_HACK
-new_sym("CLEAR")=>natv      = @natv_clear
 new_sym("QUIT")=>natv       = @natv_bye
 new_sym("GC")=>natv         = @natv_gc
 new_sym("GR")=>natv         = @natv_gr
 new_sym("COLOR")=>natv      = @natv_color
 new_sym("PLOT")=>natv       = @natv_plot
 new_sym("PRINTER")=>natv    = @natv_printer
+new_sym("HOME")=>natv       = @natv_home
+new_sym("GOTOXY")=>natv     = @natv_gotoxy
+new_sym("KEYPRESSED")=>natv = @natv_keypressed
 new_sym("READ")=>natv       = @natv_read
+new_sym("READKEY")=>natv    = @natv_readkey
 new_sym("READSTRING")=>natv = @natv_readstring
 new_sym("READFILE")=>natv   = @natv_readfile
 

src/lisp/lores.lisp

@@ -33,5 +33,6 @@
 (PLOTSIN)
 (COLOR 9)
 (PLOTCOS)
-; RETURN TO TEXT MODE - UNCOMMENT NEXT LINE
-; (GR F)
+"Press a key..."
+(READKEY)
+(GR F)

src/lisp/s-expr.pla

@@ -61,7 +61,7 @@ export var fmt_fpfrac  = 4
 export byte trace      = FALSE
 export var exception   = NULL
 export var hook_eval   = NULL // Installable hook for eval_expr()
-export var assoc_list  = NULL // SYM->value association list
+var assoc_list  = NULL // SYM->value association list
 var cons_list          = NULL
 var cons_free          = NULL
 var int_list           = NULL
@@ -80,7 +80,7 @@ const HASH_MASK = HASH_SIZE-1
 word hashtbl[HASH_SIZE]
 
 var sym_nil, sym_true, sym_quote, sym_lambda, sym_funarg, sym_set
-var sym_macro, sym_cond, sym_if, sym_label, sym_for, sym_space, sym_cr
+var sym_macro, sym_cond, sym_if, sym_label, sym_for
 var prog, prog_expr, prog_return // Current PROG expressions
 var tempstr
 
@@ -1317,16 +1317,8 @@ def natv_prin(symptr, expr)
 
   result = NULL
   while expr
-    if expr=>car == sym_space
-      result = sym_space
-      putc(' ')
-    elsif expr=>car == sym_cr
-      result = sym_cr
-      putln
-    else
-      result = eval_expr(expr=>car)
-      print_expr(result)
-    fin
+    result = eval_expr(expr=>car)
+    print_expr(result)
     expr = expr=>cdr
   loop
   return result
@@ -1610,8 +1602,6 @@ sym_true                  = new_sym("*T*")
 sym_true=>apval           = sym_true ^ NULL_HACK
 new_sym("T")=>apval       = sym_true ^ NULL_HACK
 new_sym("F")=>apval       = NULL_HACK
-sym_space                 = new_sym("SPACE")
-sym_cr                    = new_sym("CR")
 sym_lambda                = new_sym("LAMBDA")
 sym_funarg                = new_sym("FUNARG")
 sym_macro                 = new_sym("MACRO")