simon/mw-parser
1
0
Fork 0
Code Issues Pull requests Actions Packages Projects Releases Wiki Activity

Added some moderately-real tests.

Browse source
This commit is contained in:
Simon Brooke 2014-07-07 19:45:27 +01:00
parent 723a23e3dc
commit 2dc5e394cc
2 changed files with 65 additions and 54 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

93
README.md
View file

@ -4,8 +4,8 @@ A rule parser for MicroWorld
## Usage
Main entry point is (parse-rule <string>), where string takes a form detailed
in **grammar**, below. If the rule is interpretted correctly the result will
Main entry point is (parse-rule _string_), where string takes a form detailed
in __grammar__, below. If the rule is interpretted correctly the result will
be a Clojure anonymous function; if the rule is not interpretted, currently nil
is returned and there's no helpful error message.
@ -13,71 +13,76 @@ is returned and there's no helpful error message.
The generated function is a function of two arguments
* **cell** a cell in a world as defined in mw-engine.world, q.v.;
* **world** the world of which that cell forms part.
_ __cell__ a cell in a world as defined in mw-engine.world, q.v.;
_ __world__ the world of which that cell forms part.
It returns a new cell, based on the cell passed.
Actions of the rule will (can only) modify properties of the cell; there are two
properties which are special and SHOULD NOT be modified, namely the properties
**x** and **y**. Currently there is no policing that these properties are not
__x__ and __y__. Currently there is no policing that these properties are not
modified.
### Grammar
A rule comprises:
* if *conditions* then *actions*
+ if _conditions_ then _actions_
#### Conditions
where *conditions* is:
where _conditions_ is:
* *condition*
+ _condition_
+ _condition_ and _conditions_
+ _condition_ or _conditions_
or
* *condition* and *conditions*
Note that 'and' takes precedence over or, so
A *condition* is one of:
conditionA and conditionB or conditionC and conditionD
* *property* is *value*
* *property* is not *value*
* *property* is in *values*
* *property* is not in *values*
* *property* is more than *numeric-value*
* *property* is less than *numeric-value*
* *number* neighbours have *property* equal to *value*
* more than *number* neighbours have *property* equal to *value*
* fewer than *number* neighbours have *property* equal to *value*
is interpreted as
(conditionA and (conditionB or (conditionC and conditionD)))
A _condition_ is one of:
+ _property_ is _value_
+ _property_ is not _value_
+ _property_ is in _values_
+ _property_ is not in _values_
+ _property_ is more than _numeric-value_
+ _property_ is less than _numeric-value_
+ _number_ neighbours have _property_ equal to _value_
+ more than _number_ neighbours have _property_ equal to _value_
+ fewer than _number_ neighbours have _property_ equal to _value_
#### Actions
Where *actions* is:
Where _actions_ is:
* *action*
+ _action_
+ _action_ and _actions_
or
* *action* and *actions*
and _action_ is:
and *action* is:
* *property* should be *value*
+ _property_ should be _value_
#### Properties
In the above, *property* is the name of any property of a cell. Any alpha-numeric
In the above, _property_ is the name of any property of a cell. Any alpha-numeric
string of characters can form the name of a property. Actions should NOT refer
to the reserved properties **x** and **y**.
to the reserved properties __x__ and __y__.
#### Values in Conditions
Values in conditions and actions are considered slightly differently. In a
condition, a value is one of
* *symbolic-value*
* *numeric-value*
+ _symbolic-value_
+ _numeric-value_
The '...more than...' and '...less than...' conditions imply a *numeric-value*.
The '...more than...' and '...less than...' conditions imply a _numeric-value_.
Thus "if altitude is more than fertility..." is interpreted as meaning "if the value
of the property of the current cell called 'altitude' is greater than the value
of the property of the current cell called 'fertility'", whereas the apparently
@ -85,29 +90,29 @@ similar condition 'if altitude is fertility...' is interpreted as meaning
"if the value of the property of the current cell called 'altitude' is the symbol
'fertility'".
Thus *symbolic-value* is any sequence of alphanumeric characters, whereas
*numeric-value* is one of:
Thus _symbolic-value_ is any sequence of alphanumeric characters, whereas
_numeric-value_ is one of:
* *number*
* *property*
+ _number_
+ _property_
and *number* is any sequence of the decimal digits 0...9, the minus character
and _number_ is any sequence of the decimal digits 0...9, the minus character
'-' and the period character '.', provided that the minus character can only be
in the first position, and the period character can only appear once.
#### Values in Actions
A *value* in an action is one of
A _value_ in an action is one of
* *symbolic-value*
* *arithmetic-value*
* *number*
+ _symbolic-value_
+ _arithmetic-value_
+ _number_
where *arithmetic-value* is:
where _arithmetic-value_ is:
* *property* *operator* *numeric-value*
+ _property_ _operator_ _numeric-value_
and *operator* is one of the simple arithmetic operators '+', '-', '*' and '/'.
and _operator_ is one of the simple arithmetic operators '+', '-', '*' and '/'.
### Shorthand

26
test/mw_parser/core_test.clj
View file

@ -5,16 +5,22 @@
(deftest rules-tests
(testing "if altitude is less than 100 and state is forest then state should be climax and deer should be 3"
(testing "Rule parser - does not test whether generated functions actually work, just that something is generated!"
(is (parse-rule "if altitude is less than 100 and state is forest then state should be climax and deer should be 3"))
(is (let [cell (apply (eval (parse-rule "if altitude is less than 100 and state is forest then state should be climax and deer should be 3"))
(list {:state :forest :altitude 99} nil))]
(and (= (:state cell) :climax) (= (:deer cell) 3))))
(is (parse-rule "if altitude is less than 100 and state is forest then state should be climax and deer should be 3"))
(is (parse-rule "if altitude is 100 or fertility is 25 then state should be heath and fertility should be 24.3"))
(is (parse-rule "if altitude is 100 or fertility is 25 then state should be heath"))
(is (parse-rule "if deer is more than 2 and wolves is 0 and fertility is more than 20 then deer should be deer + 2"))
(is (parse-rule "if deer is more than 1 and wolves is more than 1 then deer should be deer - wolves"))
(is (parse-rule "if state is grassland and 4 neighbours have state equal to water then state should be village"))
(is (parse-rule "if state is forest and fertility is between 55 and 75 then state should be climax"))
(is (parse-rule "if 6 neighbours have state equal to water then state should be village"))
(is (parse-rule "if state is in grassland or pasture or heath and 4 neighbours are water then state should be village"))
;; ideally should also test that the rule works, but I haven't worked out how to make mw-engine.utils available
;; during eval
;; (is (let [cell (apply (eval (parse-rule "if altitude is less than 100 and state is forest then state should be climax and deer should be 3"))
;; (list {:state :forest :altitude 99} nil))]
;; (and (= (:state cell) :climax) (= (:deer cell) 3))))
))
;; * "if altitude is 100 or fertility is 25 then state should be heath and fertility should be 24.3"
;; * "if altitude is 100 or fertility is 25 then state should be heath"
;; * "if deer is more than 2 and wolves is 0 and fertility is more than 20 then deer should be deer + 2"
;; * "if deer is more than 1 and wolves is more than 1 then deer should be deer - wolves"
;;