starting on repl

[sped.git] / sped.asm

diff --git a/sped.asm b/sped.asm
index eda67b3..1e20038 100644 (file)
--- a/sped.asm
+++ b/sped.asm
@@ -1,6 +1,12 @@
+; sped - the stupidly pointless editor
+; written by pinosaur
+
+%include "fileutils.S"
 
 global main
 extern printf
+extern fflush
+extern stdout
 
 ; macros
 %macro write_str 2
@@ -13,40 +19,111 @@ extern printf
 
 section .data
     banner_str db `SPED - the stupidly pointless editor\n`, 0x00
-    readfile_str db `reading file %s\n`, 0x00
     nofile_str db `no file provided\n`, 0x00
-    argcount_str db `there are %d args\n`, 0x00
+    prompt_str db `sped > `, 0x00
+    invalidcommand_str db `invalid command\n`, 0x00
+    charcount_str db `read %i chars\n`, 0x00
+
+section .bss
+    buffer resb 4
+    buffer_lines resb 4
+    cur_line resb 4
 
 section .text
 main:
+    %define _ARGC 8
+    %define _ARGV 12
+
     push ebp
     mov ebp, esp
 
     ; read command line args
-    mov ecx, [ebp+8]
-
+    mov ecx, [ebp+_ARGC]
     cmp ecx, 1
-    jg .readFile
+    jg _main_existing
     
     ; display error msg if no file
     push nofile_str
     call printf
     mov eax, 1
-    jmp .exit
-
-.readFile:
+    jmp _main_exit
 
-    mov ebx, DWORD [ebp+12]
-    add ebx, 4
+    _main_existing:
+    mov ebx, DWORD [ebp+_ARGV]
+    add ebx, 4 ; first user arg is filename
     push DWORD [ebx]
-    push readfile_str
-    call printf
+    call readFile
+
+    mov [buffer], eax
+    mov [buffer_lines], ebx
+    mov DWORD [cur_line], 0x00
+
+    call repl
 
     mov eax, 0
-    jmp .exit
+    jmp _main_exit
+
+    _main_exit:
+    %undef _ARGC
+    %undef _ARGV
 
-.exit:
     mov esp, ebp
     pop ebp
     ret
 
+; prompt for user
+; no args - reads from globals
+repl:
+
+    %define CMDSTR 4 ; the previous line read from user
+
+    push ebp
+    mov ebp, esp
+
+    sub esp, 4
+
+    _repl_loop:
+    
+    ; print the prompt
+    push prompt_str
+    call printf
+    push DWORD [stdout]
+    call fflush
+
+    ; read line from stdin
+    push 0
+    call readLine
+
+    mov DWORD [ebp-CMDSTR], eax
+
+    ; commands are single char for now
+    cmp ecx, 1 
+    jne _repl_invalid
+
+    ; parse commands
+    mov eax, DWORD [ebp-CMDSTR]
+    mov eax, [eax]
+
+    ; q exists program
+    mov eax, DWORD [ebp-CMDSTR]
+    cmp BYTE [eax], 'q'
+    jne _repl_cmd_quit_end
+    jmp _repl_exit
+    _repl_cmd_quit_end:
+
+
+    _repl_invalid:
+    push invalidcommand_str
+    call printf
+
+    _repl_continue:
+    jmp _repl_loop
+    
+    _repl_exit:
+
+    %undef CMDSTR
+
+    mov esp, ebp
+    pop ebp
+    ret
+