branch: externals/parser-generator
commit 53980d44e55cf280731e17931a354789690a810a
Author: Christian Johansson <christ...@cvj.se>
Commit: Christian Johansson <christ...@cvj.se>
More documentation
---
README.md | 77 ++++++++++++++++++++++++++++++++++++++-------------------------
1 file changed, 47 insertions(+), 30 deletions(-)
diff --git a/README.md b/README.md
index 66e088d..6a7c9af 100644
--- a/README.md
+++ b/README.md
@@ -42,6 +42,44 @@ Example with grammar with production: S -> SaSb and S is
non-terminal and a, b a
* B, C is parts of the production RHS, if the dot is the left B is nil and C
is the entire RHS. If the dot is at the right then B is the production RHS and
C is nil, otherwise B and C contains parts of the RHS
* L is the terminal look-ahead
+### LR items for prefix (S)
+
+Calculate the set of LR items valid for any viable prefix S.
+
+### Functions
+
+``` emacs-lisp
+(require 'ert)
+
+(parser--set-grammar '((Sp S) (a b) ((Sp S) (S (S a S b)) (S e)) Sp))
+(parser--set-look-ahead-number 1)
+(parser--process-grammar)
+
+(should
+ (equal
+ '((S nil (S a S b) (a))
+ (S nil (S a S b) (e))
+ (S nil nil (a))
+ (S nil nil (e))
+ (Sp nil (S) (e)))
+ (parser--lr-items-for-prefix 'e)))
+```
+
+``` emacs-lisp
+(require 'ert)
+
+(parser--set-grammar '((Sp S) (a b) ((Sp S) (S (S a S b)) (S e)) Sp))
+(parser--set-look-ahead-number 1)
+(parser--process-grammar)
+
+(should
+ (equal
+ '((S (S) (a S b) (a))
+ (S (S) (a S b) (e))
+ (Sp (S) nil (e)))
+ (parser--lr-items-for-prefix 'S)))
+```
+
#### Formal Shift-Reduce Parsing Algorithms
#### Simple Precedence Grammars
#### Extended Precedence Grammars
@@ -120,8 +158,11 @@ Calculate the first look-ahead number of terminals of the
sentential-form `S`, e
``` emacs-lisp
(require 'ert)
+
(parser--set-grammar '((S A B C) (a b c) ((S (A B)) (A (B a) e) (B (C b) C) (C
c e)) S))
(parser--set-look-ahead-number 2)
+(parser--process-grammar)
+
(should
(equal
'((a) (a c) (a b) (c a) (b a) (e) (c) (b) (c b))
@@ -134,8 +175,11 @@ Calculate the e-free-first look-ahead number of terminals
of sentential-form `S`
``` emacs-lisp
(require 'ert)
+
(parser--set-grammar '((S A B C) (a b c) ((S (A B)) (A (B a) e) (B (C b) C) (C
c e)) S))
(parser--set-look-ahead-number 2)
+(parser--process-grammar)
+
(should
(equal
'((c b) (c a))
@@ -148,44 +192,17 @@ Calculate the look-ahead number of terminals possibly
following S.
``` emacs-lisp
(require 'ert)
+
(parser--set-grammar '((S A B) (a c d f) ((S (A a)) (A B) (B (c f) d)) S))
(parser--set-look-ahead-number 2)
+(parser--process-grammar)
+
(should
(equal
'((a))
(parser--follow 'A)))
```
-### LR items for prefix (S)
-
-Calculate the set of LR items valid for any viable prefix S.
-
-``` emacs-lisp
-(require 'ert)
-(parser--set-grammar '((Sp S) (a b) ((Sp S) (S (S a S b)) (S e)) Sp))
-(parser--set-look-ahead-number 1)
-(should
- (equal
- '((S nil (S a S b) (a))
- (S nil (S a S b) (e))
- (S nil nil (a))
- (S nil nil (e))
- (Sp nil (S) (e)))
- (parser--lr-items-for-prefix 'e)))
-```
-
-``` emacs-lisp
-(require 'ert)
-(parser--set-grammar '((Sp S) (a b) ((Sp S) (S (S a S b)) (S e)) Sp))
-(parser--set-look-ahead-number 1)
-(should
- (equal
- '((S (S) (a S b) (a))
- (S (S) (a S b) (e))
- (Sp (S) nil (e)))
- (parser--lr-items-for-prefix 'S)))
-```
-
## Test
Run in terminal `make clean && make tests && make compile`
