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New parser now well advanced, parses all but one of the test rules.

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However code generation only just started.
This commit is contained in:
simon 2015-02-12 08:11:50 +00:00
parent 72c4f45553
commit 52a4f62310
1 changed files with 129 additions and 13 deletions
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142
src/mw_parser/insta.clj
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@ -4,29 +4,145 @@
(:require [instaparse.core :as insta]))
(def grammar
(def grammar
"RULE := 'if' SPACE CONDITIONS SPACE 'then' SPACE ACTIONS;
CONDITIONS := CONDITION | CONDITION SPACE 'and' SPACE CONDITIONS;
CONDITION := DISJUNCT-CONDITION | PROPERTY-CONDITION;
DISJUNCT-CONDITION := CONDITION SPACE 'or' SPACE CONDITION;
PROPERTY-CONDITION := PROPERTY SPACE 'is' SPACE EXPRESSION;
EXPRESSION := VALUE QUALIFIER EXPRESSION | VALUE OPERATOR EXPRESSION | VALUE;
QUALIFIER := SPACE 'more' SPACE 'than' SPACE | SPACE 'less' SPACE 'than' SPACE | SPACE 'fewer' SPACE 'than' SPACE | SPACE 'equal' SPACE 'to' SPACE ;
CONDITIONS := DISJUNCT-CONDITION | CONJUNCT-CONDITION | PROPERTY-CONDITION | NEIGHBOURS-CONDITION ;
DISJUNCT-CONDITION := CONDITION SPACE 'or' SPACE CONDITIONS;
CONJUNCT-CONDITION := CONDITION SPACE 'and' SPACE CONDITIONS;
CONDITION := NEIGHBOURS-CONDITION | PROPERTY-CONDITION;
NEIGHBOURS-CONDITION := QUANTIFIER SPACE NEIGHBOURS SPACE IS SPACE PROPERTY-CONDITION | QUANTIFIER SPACE NEIGHBOURS IS EXPRESSION | QUALIFIER SPACE NEIGHBOURS-CONDITION;
PROPERTY-CONDITION := PROPERTY SPACE QUALIFIER SPACE EXPRESSION;
EXPRESSION := SIMPLE-EXPRESSION | RANGE-EXPRESSION | NUMERIC-EXPRESSION | DISJUNCT-EXPRESSION | VALUE;
SIMPLE-EXPRESSION := QUALIFIER SPACE EXPRESSION | VALUE;
DISJUNCT-EXPRESSION := 'in' SPACE DISJUNCT-VALUE;
RANGE-EXPRESSION := 'between' SPACE NUMERIC-EXPRESSION SPACE 'and' SPACE NUMERIC-EXPRESSION;
NUMERIC-EXPRESSION := VALUE | VALUE SPACE OPERATOR SPACE NUMERIC-EXPRESSION;
QUALIFIER := COMPARATIVE SPACE 'than' | EQUIVALENCE | IS SPACE QUALIFIER;
NEIGHBOURS := 'neighbour' | 'neighbor' | 'neighbours' | 'neighbors';
QUANTIFIER := NUMBER | 'some' | 'no' | 'all';
EQUIVALENCE := IS SPACE 'equal to' | 'equal to' | IS ;
COMPARATIVE := 'more' | 'less' | 'fewer';
OPERATOR := '+' | '-' | '*' | '/';
PROPERTY := SYMBOL;
DISJUNCT-VALUE := VALUE | VALUE SPACE 'or' SPACE DISJUNCT-VALUE;
VALUE := SYMBOL | NUMBER;
NUMBER := #'[0-9.]+';
IS := 'is' | 'are' | 'have';
NUMBER := #'[0-9]+' | #'[0-9]+.[0-9]+';
SYMBOL := #'[a-z]+';
ACTIONS := ACTION | ACTION SPACE 'and' SPACE ACTIONS
ACTION := SYMBOL SPACE 'should' SPACE 'be' SPACE EXPRESSION
SPACE := #'[:blank:]*'"
ACTION := SIMPLE-ACTION | PROBABLE-ACTION;
PROBABLE-ACTION := VALUE SPACE 'chance in' SPACE VALUE SPACE SIMPLE-ACTION;
SIMPLE-ACTION := SYMBOL SPACE 'should be' SPACE EXPRESSION
SPACE := #' *'"
)
(defn TODO
"Marker to indicate I'm not yet finished!"
[message]
message)
(declare generate)
(defn generate-rule
"From this `tree`, assumed to be a syntactically correct rule specification,
generate and return the appropriate rule as a function of two arguments."
[tree]
(let [left (generate (nth tree 2))
right (generate (nth tree 4))]
(list 'fn ['cell 'world] (list 'if left right))))
(defn generate-conditions
"From this `tree`, assumed to be a syntactically correct conditions clause,
generate and return the appropriate clojure fragment."
[tree]
(generate (nth tree 1)))
(defn generate-condition
[tree]
(generate (nth tree 1)))
(defn generate-conjunct-condition
[tree]
(list 'and (generate (nth tree 1))(generate (nth tree 3))))
(defn generate-disjunct-condition
[tree]
(list 'or (generate (nth tree 1))(generate (nth tree 3))))
(defn generate-qualifier
"Return more than (>), less than (<) or equal to (=) depending on the `qualifier`."
[qualifier]
(TODO "not written yet")
tree)
(defn generate-property-condition
[tree]
(let [property (generate (nth tree 1))
qualifier (generate (nth tree 2))
expression (generate (nth tree 3))]
(list qualifier (list (keyword property) 'cell) expression)))
(defn generate
"Generate code for this (fragment of a) parse tree"
[tree]
(case (first tree)
:RULE (generate-rule tree)
:CONDITIONS (generate-conditions tree)
:CONDITION (generate-condition tree)
;; :NEIGHBOURS-CONDITION (generate-neighbours-condition tree)
:DISJUNCT-CONDITION (generate-disjunct-condition tree)
:CONJUNCT-CONDITION (generate-conjunct-condition tree)
:PROPERTY-CONDITION (generate-property-condition tree)
;; :EXPRESSION (generate-expression tree)
;; :SIMPLE-EXPRESSION
tree))
(defn prune-tree
"Simplify/canonicalise the `tree`. Opportunistically replace complex fragments with
semantically identical simpler fragments"
[tree]
(TODO "not written yet")
tree)
(defn clean-tree
"Returns a structure which is structurally equivalent to `tree` but which has
the noise tokens (spaces) removed. As a side effect this new structure is a
list, not a vector, but that is not a desideratum and you should not rely in it."
[tree]
(cond
(and (coll? tree) (= (first tree) :SPACE)) nil
(coll? tree) (remove nil? (map clean-tree tree))
true tree))
(def rule-parser
(insta/parser grammar))
(def token-parser (insta/parser "TOKEN := #'[a-z]+'"))
(defn compile-rule [rule]
(generate (prune-tree (clean-tree (rule-parser rule)))))
(compile-rule "if state is climax and some neighbours have state equal to fire then 3 chance in 5 state should be fire")
(rule-parser "if state is in grassland or pasture or heath and 4 neighbours have state equal to water then state should be village")
(rule-parser "if 6 neighbours have state equal to water then state should be village")
(rule-parser "if fertility is between 55 and 75 then state should be climax")
(rule-parser "if state is forest then state should be climax")
(rule-parser "if state is in grassland or pasture or heath and 4 neighbours have state equal to water then state should be village")
(rule-parser "if altitude is less than 100 and state is forest then state should be climax and deer should be 3")
(rule-parser "if altitude is 100 or fertility is 25 then state should be heath and fertility should be 24.3")
(rule-parser "if altitude is 100 or fertility is 25 then state should be heath")
(rule-parser "if deer is more than 2 and wolves is 0 and fertility is more than 20 then deer should be deer + 2")
(rule-parser "if deer is more than 1 and wolves is more than 1 then deer should be deer - wolves")
(rule-parser "if state is grassland and 4 neighbours have state equal to water then state should be village")