branch: externals/parser-generator
commit fb7f4357389b83e92f17e58958e3726b23ef5474
Author: Christian Johansson <christ...@cvj.se>
Commit: Christian Johansson <christ...@cvj.se>
Added invalid grammar explanation message
---
parser-generator.el | 62 +++++++++++++++++++++++++++++++++++++++++--
test/parser-generator-test.el | 45 +++++++++++++++++++++++++++++++
2 files changed, 105 insertions(+), 2 deletions(-)
diff --git a/parser-generator.el b/parser-generator.el
index 1e54513d55..d2c3d231da 100644
--- a/parser-generator.el
+++ b/parser-generator.el
@@ -136,6 +136,11 @@
nil
"Hash-table of attributes related to productions.")
+(defvar
+ parser-generator--last-grammar-error
+ nil
+ "Error message of last grammar.")
+
;; Macros
@@ -687,7 +692,7 @@ Each element is a list: (list key value), optionally
UN-SORTED."
(defun parser-generator-set-grammar (G)
"Set grammar G.."
(unless (parser-generator--valid-grammar-p G)
- (error "Invalid grammar G! %s" G))
+ (error "Invalid grammar G! Error %s"
(parser-generator--get-last-grammar-error)))
(setq parser-generator--grammar G))
(defun parser-generator-process-grammar ()
@@ -706,7 +711,9 @@ Each element is a list: (list key value), optionally
UN-SORTED."
(unless
(parser-generator--valid-grammar-p
parser-generator--grammar)
- (error "Invalid grammar G!"))
+ (error
+ "Invalid grammar! Error: %s"
+ (parser-generator--get-last-grammar-error)))
(parser-generator--load-symbols)
(message "\n;; Completed process of grammar\n"))
@@ -815,17 +822,28 @@ element in B in lexicographic order."
"Return whether SYMBOL is the EOF identifier or not."
(eq symbol parser-generator--eof-identifier))
+(defun parser-generator--get-last-grammar-error ()
+ "Get last grammar validation error, if any otherwise nil."
+ parser-generator--last-grammar-error)
+
(defun parser-generator--valid-grammar-p (G)
"Return if grammar G is valid or not.
Grammar should contain list with 4 elements: non-terminals (N), terminals (T),
productions (P), start (S) where N, T and P
are lists containing symbols and/or strings and S is a symbol or string."
+ (setq parser-generator--last-grammar-error nil)
(let ((valid-p t))
(unless (listp G)
+ (setq
+ parser-generator--last-grammar-error
+ "Grammar is not a list!")
(setq valid-p nil))
(when (and
valid-p
(not (= (length G) 4)))
+ (setq
+ parser-generator--last-grammar-error
+ "Grammar is not a list of length 4! (non-terminals, terminals,
productions, start)")
(setq valid-p nil))
(when (and
valid-p
@@ -836,6 +854,26 @@ are lists containing symbols and/or strings and S is a
symbol or string."
(not (or
(stringp (nth 3 G))
(symbolp (nth 3 G))))))
+ (cond
+ ((not (listp (nth 0 G)))
+ (setq
+ parser-generator--last-grammar-error
+ "The grammars first element, the list of non-terminals, is not a
list!"))
+ ((not (listp (nth 1 G)))
+ (setq
+ parser-generator--last-grammar-error
+ "The grammars second element, the list of terminals, is not a list!"))
+ ((not (listp (nth 2 G)))
+ (setq
+ parser-generator--last-grammar-error
+ "The grammars third element, the list of productions, is not a
list!"))
+ ((not
+ (or
+ (stringp (nth 3 G))
+ (symbolp (nth 3 G))))
+ (setq
+ parser-generator--last-grammar-error
+ "The grammars fourth element, the grammar start, is neither a string
or symbol!")))
(setq valid-p nil))
(when valid-p
@@ -852,6 +890,11 @@ are lists containing symbols and/or strings and S is a
symbol or string."
(or
(symbolp non-terminal)
(stringp non-terminal))
+ (setq
+ parser-generator--last-grammar-error
+ (format
+ "Non-terminal %S is neither a string or a symbol!"
+ non-terminal))
(setq valid-p nil)))
(setq
non-terminal-index
@@ -870,6 +913,11 @@ are lists containing symbols and/or strings and S is a
symbol or string."
(or
(symbolp terminal)
(stringp terminal))
+ (setq
+ parser-generator--last-grammar-error
+ (format
+ "Terminal %S is neither a string or a symbol!"
+ terminal))
(setq valid-p nil)))
(setq
terminal-index
@@ -891,6 +939,11 @@ are lists containing symbols and/or strings and S is a
symbol or string."
(unless
(parser-generator--valid-production-p
production)
+ (setq
+ parser-generator--last-grammar-error
+ (format
+ "Production %S is not a valid production!"
+ production))
(setq valid-p nil)))
(setq
production-index
@@ -901,6 +954,11 @@ are lists containing symbols and/or strings and S is a
symbol or string."
(when (and
valid-p
(not (or (stringp start) (symbolp start))))
+ (setq
+ parser-generator--last-grammar-error
+ (format
+ "Start %S is neither a string or a symbol!"
+ start))
(setq valid-p nil))))
valid-p))
diff --git a/test/parser-generator-test.el b/test/parser-generator-test.el
index 9157633c34..1c4071c3f8 100644
--- a/test/parser-generator-test.el
+++ b/test/parser-generator-test.el
@@ -642,41 +642,81 @@
(equal
nil
(parser-generator--valid-grammar-p '((A B C) ("a" "b" "c") ((A "a"))
(A)))))
+ (message "Passed invalid grammar 1")
+ (should
+ (equal
+ (parser-generator--get-last-grammar-error)
+ "The grammars fourth element, the grammar start, is neither a string or
symbol!"))
(should
(equal
nil
(parser-generator--valid-grammar-p '((A B C) (("a" "b") "c") ((A "a"))
A))))
+ (message "Passed invalid grammar 2")
+ (should
+ (equal
+ (parser-generator--get-last-grammar-error)
+ "Terminal (\"a\" \"b\") is neither a string or a symbol!"))
(should
(equal
nil
(parser-generator--valid-grammar-p '(((A B) C) ("a" "b" "c") ((A "a"))
A))))
+ (message "Passed invalid grammar 3")
+ (should
+ (equal
+ (parser-generator--get-last-grammar-error)
+ "Non-terminal (A B) is neither a string or a symbol!"))
(should
(equal
nil
(parser-generator--valid-grammar-p '(((A B) C) ("a" "b" "c") ((A)) A))))
+ (message "Passed invalid grammar 4")
+ (should
+ (equal
+ (parser-generator--get-last-grammar-error)
+ "Non-terminal (A B) is neither a string or a symbol!"))
(should
(equal
nil
(parser-generator--valid-grammar-p "A")))
+ (message "Passed invalid grammar 5")
+ (should
+ (equal
+ (parser-generator--get-last-grammar-error)
+ "Grammar is not a list!"))
(should
(equal
nil
(parser-generator--valid-grammar-p '(A B C))))
+ (message "Passed invalid grammar 6")
+ (should
+ (equal
+ (parser-generator--get-last-grammar-error)
+ "Grammar is not a list of length 4! (non-terminals, terminals,
productions, start)"))
(should
(equal
nil
(parser-generator--valid-grammar-p '((A B)))))
+ (message "Passed invalid grammar 7")
+ (should
+ (equal
+ (parser-generator--get-last-grammar-error)
+ "Grammar is not a list of length 4! (non-terminals, terminals,
productions, start)"))
(should
(equal
nil
(parser-generator--valid-grammar-p '((A B C) (a (b c) "c") (A ("a" "b") (a
b)) (B b) (C "c")))))
+ (message "Passed invalid grammar 8")
+ (should
+ (equal
+ (parser-generator--get-last-grammar-error)
+ "Grammar is not a list of length 4! (non-terminals, terminals,
productions, start)"))
(should
(equal
@@ -687,6 +727,11 @@
(equal
nil
(parser-generator--valid-grammar-p '((A B C) ("a" "b" "c") ((A "a"
(lambda(a) (message "Was here: %s" a)) "b")) A))))
+ (message "Passed invalid grammar 9")
+ (should
+ (equal
+ (parser-generator--get-last-grammar-error)
+ "Production (A \"a\" (lambda (a) (message \"Was here: %s\" a)) \"b\") is
not a valid production!"))
(should
(equal
