print_readably flag, str and println functions

Additional flag to pr_str in RDI. If zero, returns
string without escaping special characters.

Added str and println functions, using most of the same
code as pr-str and prn

Only one test now failing for step 4.

nasm/core.asm

@@ -28,6 +28,8 @@ section .data
 
         static core_pr_str_symbol, db "pr-str"
         static core_prn_symbol, db "prn"
+        static core_str_symbol, db "str"
+        static core_println_symbol, db "println"
         
 ;; Strings
 
@@ -85,6 +87,8 @@ core_environment:
 
         core_env_native core_pr_str_symbol, core_pr_str
         core_env_native core_prn_symbol, core_prn
+        core_env_native core_str_symbol, core_str
+        core_env_native core_println_symbol, core_println
         
         ; -----------------
         ; Put the environment in RAX
@@ -435,7 +439,11 @@ core_list:
 ;; Convert arguments to a readable string, separated by a space
 ;; 
 core_pr_str:
-        
+        mov rdi, 1              ; print_readably
+        jmp core_str_functions
+core_str:
+        xor rdi, rdi
+core_str_functions:
         mov al, BYTE [rsi]
         mov ah, al
         and ah, content_mask
@@ -503,13 +511,17 @@ core_pr_str:
         ; More inputs
         mov rsi, [rsi + Cons.cdr] ; pointer
 
+        cmp rdi, 0              ; print_readably
+        je .end_append_char     ; No separator if not printing readably
+        
         ; Add separator
         push rsi
         mov rsi, r8
         mov cl, ' '
         call string_append_char
         pop rsi
-
+.end_append_char:
+        
         ; Get the type in ah for comparison at start of loop
         mov al, BYTE [rsi]
         mov ah, al
@@ -527,8 +539,11 @@ core_pr_str:
         
 ;; Print arguments readably, return nil
 core_prn:
-        ; Convert to string
         call core_pr_str
+        jmp core_prn_functions
+core_println:
+        call core_str
+core_prn_functions:
         mov rsi, rax
 
         ; Put newline at the end

nasm/printer.asm

@@ -17,6 +17,7 @@ section .data
 section .text
 
 ;; Input: Address of object in RSI
+;;        print_readably in RDI. Set to zero for false
 ;;
 ;; Output: Address of string in RAX
 ;;
@@ -41,6 +42,11 @@ pr_str:
 
         ; ---------------------------
         ; Handle string
+
+        cmp rdi, 0
+        je .string_not_readable
+        
+        ; printing readably, so escape characters
         
         call string_new         ; Output string in rax
         
@@ -102,6 +108,12 @@ pr_str:
         
         ret
 
+.string_not_readable:
+        ; Just return the string
+        call incref_object
+        mov rax, rsi
+        ret
+
         ; ----------------------------
 .not_string:
         ; Now test the container type (value, list, map, vector)

nasm/step4_if_fn_do.asm

@@ -184,6 +184,7 @@ error_throw:
         ; Print the object in RSI then quit
         cmp rsi, 0
         je .done                ; nothing to print
+        mov rdi, 1              ; print_readably
         call pr_str
         mov rsi, rax
         call print_string
@@ -1454,7 +1455,8 @@ _start:
         push rax                ; Save result
         
         ; Put into pr_str
-        mov rsi, rax            
+        mov rsi, rax
+        mov rdi, 1              ; print_readably
         call pr_str
         push rax                ; Save output string
         
@@ -1488,6 +1490,7 @@ _start:
         ; Check if an object was thrown
         cmp rsi, 0
         je .catch_done_print                ; nothing to print
+        mov rdi, 1
         call pr_str
         mov rsi, rax
         call print_string