Simplify lexer-error handling, skeletion parsing functions for types

4 files changed, 74 insertions, 47 deletions

diff --git a/src/lex.lisp b/src/lex.lisp
index d5c77a1..5b1457d 100644
--- a/src/lex.lisp
+++ b/src/lex.lisp
@@ -1,18 +1,12 @@
 (in-package #:lex)
 
-(define-condition invalid-immediate-or-keyword (error)
-  ((chr :initarg :chr
-        :initform nil
-        :reader chr)
-   (instance :initarg :instance
-             :initform nil
-             :reader instance))
+(define-condition lexer-error (error)
+  ((message :initarg :message
+            :initform nil
+            :reader message))
   (:report (lambda (condition stream)
-             (format stream
-                     "LEX failed--encountered ~a while reading ~a."
-                     (chr condition) (instance condition))))
-  (:documentation "Dedicated error for immediates/keywords which contain
-invalid characters."))
+             (format stream "~A" (message condition))))
+  (:documentation "Dedicated error for an invalid lex."))
 
 (defun file->tokens (file)
   "Opens FILE and parses returns a list of tokens, or
@@ -63,7 +57,9 @@ Comments start with a semi-colon ';' and all tokens after are ignored."
       ((alpha-char-p chr)
        (read-keyword chr))
 
-      (t (error (format nil "~a is not a valid lexical symbol.~%" chr))))))
+      (t (error 'lexer-error
+                :message
+                (format nil "LEX failled--~a is not a valid lexical symbol.~%" chr))))))
 
 (defun read-immediate (chr)
   "Reads a sequence of digits, in base 2, 8, 10, or 16.. Throws
@@ -74,7 +70,9 @@ Comments start with a semi-colon ';' and all tokens after are ignored."
       (cond ((and (not (null chr)) (digit-char-p chr))
              (read-immediate-helper (cons (read-char *standard-input* nil) chrs-so-far)))
             ((and (not (null chr)) (alpha-char-p chr))
-             (error 'invalid-immediate-or-keyword :chr chr :instance "immediate"))
+             (error 'lexer-error
+                    :message
+                    (format nil "LEX failed--encountered ~a while reading immediate.~%" chr)))
             (t (reverse chrs-so-far)))))
 
   (let* ((next (peek-char nil *standard-input* nil))
@@ -99,7 +97,9 @@ error if a digit is encountered."
       (cond ((and (not (null chr)) (alpha-char-p chr))
              (read-keyword-helper (cons (read-char *standard-input* nil) chrs-so-far)))
             ((and (not (null chr)) (digit-char-p chr))
-             (error 'invalid-immediate-or-keyword :chr chr :instance "keyword"))
+             (error 'lexer-error
+                    :message
+                    (format nil "LEX failed--encountered ~a while reading keyword.~%" chr)))
             (t (reverse chrs-so-far)))))
   (coerce (read-keyword-helper (list chr)) 'string))
 
diff --git a/src/package.lisp b/src/package.lisp
index d999783..3364856 100644
--- a/src/package.lisp
+++ b/src/package.lisp
@@ -1,4 +1,4 @@
-(defpackage #:rva
+helper(defpackage #:rva
   (:use #:cl)
   (:export #:main))
 
@@ -6,18 +6,21 @@
   (:use #:cl)
   (:export #:asm-extension?
            #:format-as-binary
-           #:label-loc
-           #:mnemonic-loc))
+           #:type-r
+           #:type-i
+           #:type-j
+           #:label-loc))
 
 (defpackage #:lex
   (:use #:cl)
-  (:export #:file->tokens
+  (:export #:lexer-error
+           #:file->tokens
            ;; exported for testing only
-           #:read-token
-           #:invalid-immediate-or-keyword))
+           #:read-token))
 
 (defpackage #:parse
   (:use #:cl)
-  (:export #:tokens->ast
+  (:export #:parser-error
+           #:tokens->ast
            ;; exported for testing only
            #:extract-label))
diff --git a/src/parse.lisp b/src/parse.lisp
index 8bd8c50..3052583 100644
--- a/src/parse.lisp
+++ b/src/parse.lisp
@@ -1,9 +1,20 @@
-(in-package #:parse)
+helper(in-package #:parse)
+
+(define-condition parser-error (error)
+  ((message :initarg :message
+            :initform nil
+            :reader message))
+  (:report (lambda (condition stream)
+             (format stream "~A" (message condition))))
+  (:documentation "Dedicated error for an invalid parse."))
 
 (defun tokens->ast (program)
-  (let ((program (remove nil (mapcar #'extract-label program))))
-    ;; TODO
-    program))
+  "Given PROGRAM, which is a list of lists of symbols,
+filters out the labels and parses."
+  ;; TODO add directives
+  (let ((program (remove nil (mapcar #'extract-label program)))
+        (i 0))
+    (mapcar (lambda (l) (extract-instruction l i)) program)))
 
 (let ((i 0))
   (defun extract-label (line)
@@ -19,3 +30,26 @@ processing."
              (satisfies (lambda (x) (equal x 'lex::colon))))
        (progn (push (cons (read-from-string id) i) util:label-loc) nil))
       (_ (progn (incf i) line)))))
+
+(defun extract-instruction (line i)
+  "Given instruction LINE, determines the expected type format and passes
+LINE and the index I to the the respective function."
+  ;; TODO add pseudo-ops (i.e., nop, mov, ...)
+  (let* ((type-map '((r-type . extract-r-type)
+                     (i-type . extract-i-type)
+                     (j-type . extract-j-type)))
+         (keyword (car line))
+         (type-fn (cdr (assoc keyword type-map))))
+    (if type-fn
+        (funcall type-fn line i)
+        (error 'parser-error
+               (format nil "PARSE failed--~a is not a known keyword.~%" (keyword))))))
+
+(defun extract-r-type (line i)
+  'r)
+
+(defun extract-i-type (line i)
+  'i)
+
+(defun extract-j-type (line i)
+  'j)
diff --git a/src/util.lisp b/src/util.lisp
index 1ea6dfc..5edee4a 100644
--- a/src/util.lisp
+++ b/src/util.lisp
@@ -11,27 +11,17 @@
   (declare (type (integer 0 *) len))
   (format nil "~V,'0b" len num))
 
-(defmacro generate-type-map (type opsize ops)
-  "Generates an alist where the key corresponds to an element in
-OPS, while the value is the index of that key (padded to OPSIZE)
-concatenated with TYPE."
-  `(let ((i 0))
-     (mapcar (lambda (x)
-               (incf i)
-               (cons x (concatenate 'string ,type
-                                    (format-as-binary i ,opsize))))
-             ,ops)))
+(defparameter type-r
+  '(ADD SUB MUL QUOT REM SFTR SFTL AND OR NOT XOR ADDV SUBV MULV DIVV CMP CEV)
+  "R-type instructions.")
+
+(defparameter type-i
+  '(LOAD LOADV ADDI SUBI SFTRI SFTLI ANDI ORI XORI STORE STOREV)
+  "I-type instructions.")
+
+(defparameter type-j
+  '(JMP JRL JAL BEQ BGT BUF BOF PUSH POP)
+  "J-type instructions.")
 
 (defparameter label-loc '()
   "A symbol table mapping label names to line indices.")
-
-(defparameter mnemonic-loc
-  `(,@(generate-type-map "00" 5
-                         '(ADD SUB MUL QUOT REM SFTR SFTL AND OR NOT
-                           XOR ADDV SUBV MULV DIVV CMP CEV))
-    ,@(generate-type-map "01" 4
-                         '(LOAD LOADV ADDI SUBI SFTRI SFTLI ANDI ORI
-                           XORI STORE STOREV))
-    ,@(generate-type-map "10" 4
-                         '(JMP JRL JAL BEQ BGT BUF BOF PUSH POP)))
-  "An alist mapping known mnemonics to their binary representation.")