зеркало из https://github.com/mozilla/pjs.git
Implemented variant-constraints. Added all-state-transitions.
This commit is contained in:
waldemar%netscape.com
Родитель
5357f74106
Коммит
15793d4cc3
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@ -106,8 +106,14 @@
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(ash 1 (terminal-number grammar terminal)))
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; Return a terminalset containing all terminals in the grammar.
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(defun make-full-terminalset (grammar)
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(1- (ash 1 (length (grammar-terminals grammar)))))
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; Call f on every terminal in the terminalset in reverse order.
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(defun map-terminalset-reverse (f grammar terminalset)
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(assert-true (>= terminalset 0))
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(do ()
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((zerop terminalset))
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(let ((last (1- (integer-length terminalset))))
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@ -124,7 +130,12 @@
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(defun print-terminalset (grammar terminalset &optional (stream t))
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(pprint-fill stream (terminalset-list grammar terminalset) nil))
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(let ((first t))
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(dolist (terminal (terminalset-list grammar terminalset))
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(if first
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(setq first nil)
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(format stream " ~:_"))
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(write terminal :stream stream))))
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;;; ------------------------------------------------------------------------------------------------------
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@ -153,7 +164,8 @@
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;;; A constraint modifies the rhs of a production. The constraint applies just before the pos-th
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;;; general grammar symbol on the rhs of the production.
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(defstruct (constraint (:constructor nil) (:copier nil) (:predicate constraint?))
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(pos nil :type integer :read-only t)) ;Position of this constraint; ranges between 0 and length(general-production-rhs), inclusive.
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(pos nil :type integer :read-only t) ;Position of this constraint; ranges between 0 and length(general-production-rhs), inclusive.
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(terminalset nil :type (or null terminalset))) ;Set of allowed lookahead terminals; null until terminals are numbered
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;;; A lookahead-constraint imposes a restriction on the current lookahead terminal when matching
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@ -163,8 +175,7 @@
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(:constructor make-lookahead-constraint (pos forbidden-terminals source))
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(:predicate lookahead-constraint?))
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(forbidden-terminals nil :type list :read-only t) ;List of forbidden terminals
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(source nil :type list :read-only t) ;List of grammar symbols (terminals or nonterminals) that produced the list of forbidden terminals
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(terminalset nil :type (or null terminalset))) ;Set of allowed terminals (complement of forbidden-terminals); null until terminals are numbered
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(source nil :type list :read-only t)) ;List of grammar symbols (terminals or nonterminals) that produced the list of forbidden terminals
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; Emit markup for a lookahead-constraint.
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@ -182,20 +193,21 @@
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(format stream "-~{ ~:_~W~}" (lookahead-constraint-source lookahead-constraint))))
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;;; A no-line-break-constraint succeeds only when there is no line break at the current position.
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(defstruct (no-line-break-constraint (:include constraint)
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(:constructor make-no-line-break-constraint (pos))
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(:predicate no-line-break-constraint?)))
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;;; A variant-constraint succeeds only when there is no line break at the current position.
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(defstruct (variant-constraint (:include constraint)
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(:constructor make-variant-constraint (pos name))
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(:predicate variant-constraint?))
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(name nil :read-only t)) ;This variant-constraint's depict name
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; Emit markup for a no-line-break-constraint.
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(defun depict-no-line-break-constraint (markup-stream no-line-break-constraint)
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(declare (ignore no-line-break-constraint))
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(depict markup-stream :no-line-break))
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; Emit markup for a variant-constraint.
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(defun depict-variant-constraint (markup-stream variant-constraint)
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(depict markup-stream (variant-constraint-name variant-constraint)))
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(defmethod print-object ((no-line-break-constraint no-line-break-constraint) stream)
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(print-unreadable-object (no-line-break-constraint stream)))
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(defmethod print-object ((variant-constraint variant-constraint) stream)
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(print-unreadable-object (variant-constraint stream)
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(write (variant-constraint-name variant-constraint) :stream stream)))
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;;; ------------------------------------------------------------------------------------------------------
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@ -237,12 +249,13 @@
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0)))
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; Return the general-production's lookahead-constraint's terminalset at the given position.
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(defun general-production-lookahead-constraint (general-production pos)
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(dolist (constraint (general-production-constraints general-production) *full-terminalset*)
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(when (and (lookahead-constraint? constraint)
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(= (constraint-pos constraint) pos))
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(return (lookahead-constraint-terminalset constraint)))))
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; Return the general-production's constraint's terminalset at the given position.
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(defun general-production-constraint (general-production pos)
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(let ((terminalset *full-terminalset*))
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(dolist (constraint (general-production-constraints general-production))
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(when (= (constraint-pos constraint) pos)
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(terminalset-intersection-f terminalset (constraint-terminalset constraint))))
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terminalset))
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; Emit a markup paragraph for the left-hand-side of a general production.
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@ -257,8 +270,8 @@
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(cond
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((lookahead-constraint? production-rhs-component)
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(depict-lookahead-constraint markup-stream production-rhs-component))
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((no-line-break-constraint? production-rhs-component)
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(depict-no-line-break-constraint markup-stream production-rhs-component))
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((variant-constraint? production-rhs-component)
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(depict-variant-constraint markup-stream production-rhs-component))
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(t (depict-general-grammar-symbol markup-stream production-rhs-component :reference subscript))))
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@ -785,7 +798,7 @@
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(let ((transition-cons (pprint-pop)))
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(pprint-logical-block (stream nil)
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(pprint-fill stream (car transition-cons) nil)
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(format stream " ~2I~_=> " (car transition-cons))
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(format stream " ~2I~_=> ")
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(print-transition (cdr transition-cons) stream))
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(format stream " ~:_")))))
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(when (state-gotos state)
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@ -998,6 +1011,8 @@
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(terminals nil :type simple-vector :read-only t) ;Vector of all terminals (in order of terminal numbers)
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(nonterminals nil :type simple-vector :read-only t) ;Vector of all nonterminals (in a depth-first order)
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(nonterminals-list nil :type list :read-only t) ;List version of the nonterminals vector
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(terminal-variants nil :type hash-table :read-only t) ;Hash table of terminal -> list of that terminal's variants, including the terminal itself
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(terminal-terminalsets nil :type hash-table :read-only t) ;Hash table of terminal -> terminalset of that terminal's variants, including the terminal itself
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(terminal-numbers nil :type hash-table :read-only t) ;Hash table of terminal -> terminal number
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(terminal-actions nil :type hash-table :read-only t) ;Hash table of terminal -> list of (action-symbol . action-function-or-nil)
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(rules nil :type hash-table :read-only t) ;Hash table of nonterminal -> rule
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@ -1012,6 +1027,20 @@
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(action-signatures nil :type (or null hash-table))) ;Hash table of grammar-symbol -> list of (action-symbol . type-or-type-expr)
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; Return a list of the given terminal's variants, including the terminal itself.
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(declaim (inline terminal-variants))
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(defun terminal-variants (grammar terminal)
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(or (gethash terminal (grammar-terminal-variants grammar))
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(error "Can't find terminal ~S" terminal)))
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; Return a terminalset of the given terminal's variants, including the terminal itself.
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(declaim (inline terminal-terminalset))
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(defun terminal-terminalset (grammar terminal)
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(or (gethash terminal (grammar-terminal-terminalsets grammar))
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(error "Can't find terminal ~S" terminal)))
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; Return a rule for the given nonterminal lhs.
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(defun grammar-rule (grammar lhs)
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(or (gethash lhs (grammar-rules grammar))
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@ -1072,6 +1101,7 @@
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; G is the terminalset of all terminals x that satisfy
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; symbol ==>* x rest,
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; where rest is an arbitrary string of grammar symbols.
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;
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; P is the terminalset of all terminals x that satisfy
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; symbol x ==> x
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(defun symbol-initial-terminals (grammar symbol)
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@ -1079,7 +1109,7 @@
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(if (nonterminal? symbol)
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(let ((rule (grammar-rule grammar symbol)))
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(values (rule-initial-terminals rule) (rule-passthrough-terminals rule)))
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(values (make-terminalset grammar symbol) *empty-terminalset*)))
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(values (terminal-terminalset grammar symbol) *empty-terminalset*)))
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; Given an arbitrary string of grammar symbols, a list of constraints, and an initial position,
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@ -1090,21 +1120,25 @@
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; G is the terminalset of all terminals x that satisfy
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; symbol-string ==>* x rest,
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; where rest is an arbitrary string of grammar symbols.
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;
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; P is the terminalset of all terminals x that satisfy
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; symbol-string x ==> x
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;
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; The constraints' positions are relative to the given initial position, which specifies the position
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; of the first grammar-symbol in the symbol-string. The constraints must be listed in order of
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; increasing positions.
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(defun string-initial-terminals (grammar symbol-string constraints pos)
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; increasing positions. If ignore-initial-constraints is true, ignore the constraints located at pos
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; but include the constraints at subsequent positions if applicable.
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(defun string-initial-terminals (grammar symbol-string constraints pos ignore-initial-constraints)
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(do ((symbol-string symbol-string (cdr symbol-string))
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(pos pos (1+ pos))
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(initial-terminals *empty-terminalset*)
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(passthrough-terminals *full-terminalset*))
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((terminalset-empty? passthrough-terminals) (values initial-terminals *empty-terminalset*))
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(dolist (constraint constraints)
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(when (and (lookahead-constraint? constraint)
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(= (constraint-pos constraint) pos))
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(terminalset-intersection-f passthrough-terminals (lookahead-constraint-terminalset constraint))))
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(if ignore-initial-constraints
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(setq ignore-initial-constraints nil)
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(dolist (constraint constraints)
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(when (= (constraint-pos constraint) pos)
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(terminalset-intersection-f passthrough-terminals (constraint-terminalset constraint)))))
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(if symbol-string
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(multiple-value-bind (generate passthrough) (symbol-initial-terminals grammar (first symbol-string))
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(terminalset-union-f initial-terminals (terminalset-intersection passthrough-terminals generate))
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@ -1115,14 +1149,15 @@
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; Intern attributed or generic nonterminals in the production's lhs and rhs. Replace
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; (:- <terminal> ... <terminal>) or (:-- (<grammar-symbol> ... <grammar-symbol>) <terminal> ... <terminal>)
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; sublists in the rhs with lookahead-constraints and put these, in order, after the third element of
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; the returned list. Also replace :~ symbols with no-line-break-constraints.
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; the returned list. Also replace variant constraint symbols with variant-constraints.
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; The variant-constraint-names parameter should be a list of possible variant constraint symbols.
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; Return the resulting production source.
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(defun intern-production-source (grammar-parametrization production-source)
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(defun intern-production-source (grammar-parametrization variant-constraint-names production-source)
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(assert-type production-source (tuple (or user-nonterminal cons) (list (or user-grammar-symbol cons)) identifier))
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(let ((production-lhs-source (first production-source))
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(production-rhs-source (second production-source))
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(production-name (third production-source)))
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(if (or (consp production-lhs-source) (some #'consp production-rhs-source) (find ':~ production-rhs-source))
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(if (or (consp production-lhs-source) (some #'consp production-rhs-source) (intersection variant-constraint-names production-rhs-source))
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(multiple-value-bind (lhs-nonterminal lhs-arguments) (grammar-parametrization-intern grammar-parametrization production-lhs-source)
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(let ((rhs nil)
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(constraints nil)
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@ -1139,8 +1174,8 @@
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(push
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(make-lookahead-constraint pos (assert-non-null (rest lookaheads)) (assert-non-null (first lookaheads)))
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constraints)))
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((eq component-source ':~)
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(push (make-no-line-break-constraint pos) constraints))
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((member component-source variant-constraint-names)
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(push (make-variant-constraint pos component-source) constraints))
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(t
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(push (grammar-parametrization-intern grammar-parametrization component-source lhs-arguments) rhs)
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(incf pos))))
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@ -1160,36 +1195,45 @@
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; nonterminal can have attributes, thereby designating a specialization instead of a fully
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; generic production.
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;
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; variant-constraint-names should be a list of keywords that are variant-constraints instead of nonterminals
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;
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; A variant-generator is either nil or a function that takes a terminal and outputs a list of its variants.
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; Each variant is specified as a cons of:
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; A variant terminal
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; A list of names of variant constraints which exclude this variant terminal
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;
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; The rhs can also contain lookahead constraints of the form
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; (:- <terminal> ... <terminal>)
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; which indicate that the following terminal must not be one of the listed terminals. The form
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; (:-- (<grammar-symbol> ... <grammar-symbol>) <terminal> ... <terminal>)
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; does the same thing except that it prints the grammar-symbols instead of the terminals when
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; the production is printed. The form
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; :~
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; indicates that a line break is not allowed at the current position between terminals (this
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; constraint is currently ignored by the parser but does show up in printed grammars).
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; <constraint>
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; where <constraint> is a member of the variant-constraint-names list also represents a constraint on the following
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; terminal; that constraint excludes all variants that were returned by variant-generator along with this constraint.
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;
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; excluded-nonterminals-source is a list of nonterminals not used in the grammar. Productions,
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; excluded-nonterminals is a list of nonterminals not used in the grammar. Productions,
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; including productions expanded from generic productions, that have one of these nonterminals
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; on the lhs are ignored.
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(defun make-grammar (grammar-parametrization start-symbol grammar-source &optional excluded-nonterminals-source)
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(let ((interned-grammar-source
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(defun make-grammar (grammar-parametrization start-symbol grammar-source &key variant-constraint-names variant-generator excluded-nonterminals)
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(let ((variant-constraint-forbid-lists (mapcar #'list variant-constraint-names))
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(interned-grammar-source
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(mapcar #'(lambda (production-source)
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(intern-production-source grammar-parametrization production-source))
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(intern-production-source grammar-parametrization variant-constraint-names production-source))
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grammar-source))
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(rules (make-hash-table :test #'eq))
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(terminals-hash (make-hash-table :test *grammar-symbol-=*))
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(terminal-variants (make-hash-table :test *grammar-symbol-=*))
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(general-productions (make-hash-table :test #'equal))
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(production-number 0)
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(max-production-length 1)
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(excluded-nonterminals-hash (make-hash-table :test *grammar-symbol-=*))
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(lookahead-constraints nil))
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(constraints nil))
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;Set up excluded-nonterminals-hash. The values of the hash table are either :seen or :unseen
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;depending on whether a production with the particular nonterminal has been seen yet.
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(dolist (excluded-nonterminal-source excluded-nonterminals-source)
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(setf (gethash (grammar-parametrization-intern grammar-parametrization excluded-nonterminal-source nil) excluded-nonterminals-hash)
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(dolist (excluded-nonterminal excluded-nonterminals)
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(setf (gethash (grammar-parametrization-intern grammar-parametrization excluded-nonterminal nil) excluded-nonterminals-hash)
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:unseen))
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;Create the starting production: *start-nonterminal* ==> start-symbol
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@ -1243,6 +1287,16 @@
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(create-production production-lhs production-rhs production-constraints production-name)))))))
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(when variant-generator
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(dolist (terminal (hash-table-keys terminals-hash))
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(dolist (variant-and-constraints (funcall variant-generator terminal))
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(let ((variant (first variant-and-constraints)))
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(push variant (gethash terminal terminal-variants))
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(setf (gethash variant terminals-hash) t)
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(dolist (constraint (rest variant-and-constraints))
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(push variant (cdr (assoc constraint variant-constraint-forbid-lists))))))))
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;Change all values of the rules hash table to contain rule structures
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;instead of mere lists of rules. Also check that all referenced nonterminals
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;have been defined.
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@ -1254,8 +1308,8 @@
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(unless (gethash grammar-symbol rules)
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(error "Nonterminal ~S used but not defined" grammar-symbol))))
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(dolist (constraint (production-constraints rule-production))
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(push constraint constraints)
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(when (lookahead-constraint? constraint)
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(push constraint lookahead-constraints)
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(dolist (lookahead-terminal (lookahead-constraint-forbidden-terminals constraint))
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(unless (gethash lookahead-terminal terminals-hash)
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(warn "Lookahead terminal ~S not used in main grammar" lookahead-terminal)
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@ -1282,16 +1336,21 @@
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(let ((terminals (coerce (cons *end-marker* (sorted-hash-table-keys terminals-hash))
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'simple-vector))
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(terminal-terminalsets (make-hash-table :test *grammar-symbol-=*))
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(nonterminals (coerce nonterminals-list 'simple-vector)))
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(dotimes (n (length terminals))
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(setf (gethash (svref terminals n) terminals-hash) n))
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(let ((terminal (svref terminals n)))
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(setf (gethash terminal terminals-hash) n)
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(pushnew terminal (gethash terminal terminal-variants))))
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(dotimes (n (length nonterminals))
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(setf (rule-number (gethash (svref nonterminals n) rules)) n))
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(let ((grammar (allocate-grammar
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:argument-attributes (grammar-parametrization-argument-attributes grammar-parametrization)
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:terminals terminals
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:nonterminals-list nonterminals-list
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:nonterminals nonterminals
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:nonterminals-list nonterminals-list
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:terminal-variants terminal-variants
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:terminal-terminalsets terminal-terminalsets
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:terminal-numbers terminals-hash
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:terminal-actions (make-hash-table :test *grammar-symbol-=*)
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:rules rules
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@ -1301,12 +1360,34 @@
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:n-productions production-number
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:items-hash (make-hash-table :test #'equal))))
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;Compute the terminalsets in the lookahead-constraints.
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(dolist (lookahead-constraint lookahead-constraints)
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;Compute the terminalsets in the terminal-terminalsets.
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(dotimes (n (length terminals))
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(let ((terminal (svref terminals n))
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(terminalset *empty-terminalset*))
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(dolist (variant (terminal-variants grammar terminal))
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(terminalset-union-f terminalset (make-terminalset grammar variant)))
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(setf (gethash terminal terminal-terminalsets) terminalset)))
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;Replace the cdr of each element of variant-constraint-forbid-lists with a terminalset of all
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;terminals not forbidden by that constraint.
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(dolist (constraint-and-forbidden-variants variant-constraint-forbid-lists)
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(let ((terminalset *full-terminalset*))
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(dolist (forbidden-terminal (lookahead-constraint-forbidden-terminals lookahead-constraint))
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(terminalset-difference-f terminalset (make-terminalset grammar forbidden-terminal)))
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(setf (lookahead-constraint-terminalset lookahead-constraint) terminalset)))
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(dolist (variant (rest constraint-and-forbidden-variants))
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(terminalset-difference-f terminalset (ash 1 (gethash variant terminals-hash)))
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(setf (rest constraint-and-forbidden-variants) terminalset))))
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;Compute the terminalsets in the constraints.
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||||
(dolist (constraint constraints)
|
||||
(cond
|
||||
((lookahead-constraint? constraint)
|
||||
(let ((terminalset *full-terminalset*))
|
||||
(dolist (forbidden-terminal (lookahead-constraint-forbidden-terminals constraint))
|
||||
(terminalset-difference-f terminalset (terminal-terminalset grammar forbidden-terminal)))
|
||||
(setf (constraint-terminalset constraint) terminalset)))
|
||||
((variant-constraint? constraint)
|
||||
(setf (constraint-terminalset constraint) (assert-non-null (cdr (assoc (variant-constraint-name constraint)
|
||||
variant-constraint-forbid-lists)))))
|
||||
(t (error "Unknown constraint ~S" constraint))))
|
||||
|
||||
;Compute the values of passthrough-terminals and initial-terminals in each rule.
|
||||
(do ((changed t))
|
||||
|
|
@ -1318,7 +1399,7 @@
|
|||
(new-passthrough-terminals *empty-terminalset*))
|
||||
(dolist (production (rule-productions rule))
|
||||
(multiple-value-bind (production-initial-terminals production-passthrough-terminals)
|
||||
(string-initial-terminals grammar (production-rhs production) (production-constraints production) 0)
|
||||
(string-initial-terminals grammar (production-rhs production) (production-constraints production) 0 nil)
|
||||
(terminalset-union-f new-initial-terminals production-initial-terminals)
|
||||
(terminalset-union-f new-passthrough-terminals production-passthrough-terminals)))
|
||||
(unless (terminalset-= new-initial-terminals (rule-initial-terminals rule))
|
||||
|
|
@ -1382,9 +1463,11 @@
|
|||
(format stream "~:@_ | ")))
|
||||
(pprint-indent :block 2 stream)
|
||||
(when details
|
||||
(format stream "~:@_Initial terminals: ~@_~@<~:[~;<epsilon> ~:_~]~{~W ~:_~}~:>"
|
||||
(not (terminalset-empty? (rule-passthrough-terminals rule)))
|
||||
(terminalset-list grammar (rule-initial-terminals rule)))))
|
||||
(format stream "~:@_Initial terminals: ~@_")
|
||||
(pprint-logical-block (stream nil)
|
||||
(unless (terminalset-empty? (rule-passthrough-terminals rule))
|
||||
(format stream "<epsilon> ~:_"))
|
||||
(print-terminalset grammar (rule-initial-terminals rule) stream))))
|
||||
(pprint-newline :mandatory stream))
|
||||
(pprint-exit-if-list-exhausted)
|
||||
(pprint-newline :mandatory stream)))
|
||||
|
|
@ -1433,6 +1516,18 @@
|
|||
(sort equivalences #'< :key #'(lambda (equivalence)
|
||||
(state-number (first equivalence))))))
|
||||
|
||||
; Call f on each state in the grammar, in order of state numbers.
|
||||
; f should take two parameters:
|
||||
; a state;
|
||||
; a hash table of terminal -> transition
|
||||
(defun all-state-transitions (f grammar)
|
||||
(let ((transitions-hash (make-hash-table :test *grammar-symbol-=*)))
|
||||
(dolist (state (grammar-states grammar))
|
||||
(dolist (transition-pair (state-transitions state))
|
||||
(setf (gethash (car transition-pair) transitions-hash) (cdr transition-pair)))
|
||||
(funcall f state transitions-hash)
|
||||
(clrhash transitions-hash))))
|
||||
|
||||
|
||||
;;; ------------------------------------------------------------------------------------------------------
|
||||
;;; YACC OUTPUT
|
||||
|
|
|
|||
|
|
@ -106,8 +106,14 @@
|
|||
(ash 1 (terminal-number grammar terminal)))
|
||||
|
||||
|
||||
; Return a terminalset containing all terminals in the grammar.
|
||||
(defun make-full-terminalset (grammar)
|
||||
(1- (ash 1 (length (grammar-terminals grammar)))))
|
||||
|
||||
|
||||
; Call f on every terminal in the terminalset in reverse order.
|
||||
(defun map-terminalset-reverse (f grammar terminalset)
|
||||
(assert-true (>= terminalset 0))
|
||||
(do ()
|
||||
((zerop terminalset))
|
||||
(let ((last (1- (integer-length terminalset))))
|
||||
|
|
@ -124,7 +130,12 @@
|
|||
|
||||
|
||||
(defun print-terminalset (grammar terminalset &optional (stream t))
|
||||
(pprint-fill stream (terminalset-list grammar terminalset) nil))
|
||||
(let ((first t))
|
||||
(dolist (terminal (terminalset-list grammar terminalset))
|
||||
(if first
|
||||
(setq first nil)
|
||||
(format stream " ~:_"))
|
||||
(write terminal :stream stream))))
|
||||
|
||||
|
||||
;;; ------------------------------------------------------------------------------------------------------
|
||||
|
|
@ -153,7 +164,8 @@
|
|||
;;; A constraint modifies the rhs of a production. The constraint applies just before the pos-th
|
||||
;;; general grammar symbol on the rhs of the production.
|
||||
(defstruct (constraint (:constructor nil) (:copier nil) (:predicate constraint?))
|
||||
(pos nil :type integer :read-only t)) ;Position of this constraint; ranges between 0 and length(general-production-rhs), inclusive.
|
||||
(pos nil :type integer :read-only t) ;Position of this constraint; ranges between 0 and length(general-production-rhs), inclusive.
|
||||
(terminalset nil :type (or null terminalset))) ;Set of allowed lookahead terminals; null until terminals are numbered
|
||||
|
||||
|
||||
;;; A lookahead-constraint imposes a restriction on the current lookahead terminal when matching
|
||||
|
|
@ -163,8 +175,7 @@
|
|||
(:constructor make-lookahead-constraint (pos forbidden-terminals source))
|
||||
(:predicate lookahead-constraint?))
|
||||
(forbidden-terminals nil :type list :read-only t) ;List of forbidden terminals
|
||||
(source nil :type list :read-only t) ;List of grammar symbols (terminals or nonterminals) that produced the list of forbidden terminals
|
||||
(terminalset nil :type (or null terminalset))) ;Set of allowed terminals (complement of forbidden-terminals); null until terminals are numbered
|
||||
(source nil :type list :read-only t)) ;List of grammar symbols (terminals or nonterminals) that produced the list of forbidden terminals
|
||||
|
||||
|
||||
; Emit markup for a lookahead-constraint.
|
||||
|
|
@ -182,20 +193,21 @@
|
|||
(format stream "-~{ ~:_~W~}" (lookahead-constraint-source lookahead-constraint))))
|
||||
|
||||
|
||||
;;; A no-line-break-constraint succeeds only when there is no line break at the current position.
|
||||
(defstruct (no-line-break-constraint (:include constraint)
|
||||
(:constructor make-no-line-break-constraint (pos))
|
||||
(:predicate no-line-break-constraint?)))
|
||||
;;; A variant-constraint succeeds only when there is no line break at the current position.
|
||||
(defstruct (variant-constraint (:include constraint)
|
||||
(:constructor make-variant-constraint (pos name))
|
||||
(:predicate variant-constraint?))
|
||||
(name nil :read-only t)) ;This variant-constraint's depict name
|
||||
|
||||
|
||||
; Emit markup for a no-line-break-constraint.
|
||||
(defun depict-no-line-break-constraint (markup-stream no-line-break-constraint)
|
||||
(declare (ignore no-line-break-constraint))
|
||||
(depict markup-stream :no-line-break))
|
||||
; Emit markup for a variant-constraint.
|
||||
(defun depict-variant-constraint (markup-stream variant-constraint)
|
||||
(depict markup-stream (variant-constraint-name variant-constraint)))
|
||||
|
||||
|
||||
(defmethod print-object ((no-line-break-constraint no-line-break-constraint) stream)
|
||||
(print-unreadable-object (no-line-break-constraint stream)))
|
||||
(defmethod print-object ((variant-constraint variant-constraint) stream)
|
||||
(print-unreadable-object (variant-constraint stream)
|
||||
(write (variant-constraint-name variant-constraint) :stream stream)))
|
||||
|
||||
|
||||
;;; ------------------------------------------------------------------------------------------------------
|
||||
|
|
@ -237,12 +249,13 @@
|
|||
0)))
|
||||
|
||||
|
||||
; Return the general-production's lookahead-constraint's terminalset at the given position.
|
||||
(defun general-production-lookahead-constraint (general-production pos)
|
||||
(dolist (constraint (general-production-constraints general-production) *full-terminalset*)
|
||||
(when (and (lookahead-constraint? constraint)
|
||||
(= (constraint-pos constraint) pos))
|
||||
(return (lookahead-constraint-terminalset constraint)))))
|
||||
; Return the general-production's constraint's terminalset at the given position.
|
||||
(defun general-production-constraint (general-production pos)
|
||||
(let ((terminalset *full-terminalset*))
|
||||
(dolist (constraint (general-production-constraints general-production))
|
||||
(when (= (constraint-pos constraint) pos)
|
||||
(terminalset-intersection-f terminalset (constraint-terminalset constraint))))
|
||||
terminalset))
|
||||
|
||||
|
||||
; Emit a markup paragraph for the left-hand-side of a general production.
|
||||
|
|
@ -257,8 +270,8 @@
|
|||
(cond
|
||||
((lookahead-constraint? production-rhs-component)
|
||||
(depict-lookahead-constraint markup-stream production-rhs-component))
|
||||
((no-line-break-constraint? production-rhs-component)
|
||||
(depict-no-line-break-constraint markup-stream production-rhs-component))
|
||||
((variant-constraint? production-rhs-component)
|
||||
(depict-variant-constraint markup-stream production-rhs-component))
|
||||
(t (depict-general-grammar-symbol markup-stream production-rhs-component :reference subscript))))
|
||||
|
||||
|
||||
|
|
@ -785,7 +798,7 @@
|
|||
(let ((transition-cons (pprint-pop)))
|
||||
(pprint-logical-block (stream nil)
|
||||
(pprint-fill stream (car transition-cons) nil)
|
||||
(format stream " ~2I~_=> " (car transition-cons))
|
||||
(format stream " ~2I~_=> ")
|
||||
(print-transition (cdr transition-cons) stream))
|
||||
(format stream " ~:_")))))
|
||||
(when (state-gotos state)
|
||||
|
|
@ -998,6 +1011,8 @@
|
|||
(terminals nil :type simple-vector :read-only t) ;Vector of all terminals (in order of terminal numbers)
|
||||
(nonterminals nil :type simple-vector :read-only t) ;Vector of all nonterminals (in a depth-first order)
|
||||
(nonterminals-list nil :type list :read-only t) ;List version of the nonterminals vector
|
||||
(terminal-variants nil :type hash-table :read-only t) ;Hash table of terminal -> list of that terminal's variants, including the terminal itself
|
||||
(terminal-terminalsets nil :type hash-table :read-only t) ;Hash table of terminal -> terminalset of that terminal's variants, including the terminal itself
|
||||
(terminal-numbers nil :type hash-table :read-only t) ;Hash table of terminal -> terminal number
|
||||
(terminal-actions nil :type hash-table :read-only t) ;Hash table of terminal -> list of (action-symbol . action-function-or-nil)
|
||||
(rules nil :type hash-table :read-only t) ;Hash table of nonterminal -> rule
|
||||
|
|
@ -1012,6 +1027,20 @@
|
|||
(action-signatures nil :type (or null hash-table))) ;Hash table of grammar-symbol -> list of (action-symbol . type-or-type-expr)
|
||||
|
||||
|
||||
; Return a list of the given terminal's variants, including the terminal itself.
|
||||
(declaim (inline terminal-variants))
|
||||
(defun terminal-variants (grammar terminal)
|
||||
(or (gethash terminal (grammar-terminal-variants grammar))
|
||||
(error "Can't find terminal ~S" terminal)))
|
||||
|
||||
|
||||
; Return a terminalset of the given terminal's variants, including the terminal itself.
|
||||
(declaim (inline terminal-terminalset))
|
||||
(defun terminal-terminalset (grammar terminal)
|
||||
(or (gethash terminal (grammar-terminal-terminalsets grammar))
|
||||
(error "Can't find terminal ~S" terminal)))
|
||||
|
||||
|
||||
; Return a rule for the given nonterminal lhs.
|
||||
(defun grammar-rule (grammar lhs)
|
||||
(or (gethash lhs (grammar-rules grammar))
|
||||
|
|
@ -1072,6 +1101,7 @@
|
|||
; G is the terminalset of all terminals x that satisfy
|
||||
; symbol ==>* x rest,
|
||||
; where rest is an arbitrary string of grammar symbols.
|
||||
;
|
||||
; P is the terminalset of all terminals x that satisfy
|
||||
; symbol x ==> x
|
||||
(defun symbol-initial-terminals (grammar symbol)
|
||||
|
|
@ -1079,7 +1109,7 @@
|
|||
(if (nonterminal? symbol)
|
||||
(let ((rule (grammar-rule grammar symbol)))
|
||||
(values (rule-initial-terminals rule) (rule-passthrough-terminals rule)))
|
||||
(values (make-terminalset grammar symbol) *empty-terminalset*)))
|
||||
(values (terminal-terminalset grammar symbol) *empty-terminalset*)))
|
||||
|
||||
|
||||
; Given an arbitrary string of grammar symbols, a list of constraints, and an initial position,
|
||||
|
|
@ -1090,21 +1120,25 @@
|
|||
; G is the terminalset of all terminals x that satisfy
|
||||
; symbol-string ==>* x rest,
|
||||
; where rest is an arbitrary string of grammar symbols.
|
||||
;
|
||||
; P is the terminalset of all terminals x that satisfy
|
||||
; symbol-string x ==> x
|
||||
;
|
||||
; The constraints' positions are relative to the given initial position, which specifies the position
|
||||
; of the first grammar-symbol in the symbol-string. The constraints must be listed in order of
|
||||
; increasing positions.
|
||||
(defun string-initial-terminals (grammar symbol-string constraints pos)
|
||||
; increasing positions. If ignore-initial-constraints is true, ignore the constraints located at pos
|
||||
; but include the constraints at subsequent positions if applicable.
|
||||
(defun string-initial-terminals (grammar symbol-string constraints pos ignore-initial-constraints)
|
||||
(do ((symbol-string symbol-string (cdr symbol-string))
|
||||
(pos pos (1+ pos))
|
||||
(initial-terminals *empty-terminalset*)
|
||||
(passthrough-terminals *full-terminalset*))
|
||||
((terminalset-empty? passthrough-terminals) (values initial-terminals *empty-terminalset*))
|
||||
(dolist (constraint constraints)
|
||||
(when (and (lookahead-constraint? constraint)
|
||||
(= (constraint-pos constraint) pos))
|
||||
(terminalset-intersection-f passthrough-terminals (lookahead-constraint-terminalset constraint))))
|
||||
(if ignore-initial-constraints
|
||||
(setq ignore-initial-constraints nil)
|
||||
(dolist (constraint constraints)
|
||||
(when (= (constraint-pos constraint) pos)
|
||||
(terminalset-intersection-f passthrough-terminals (constraint-terminalset constraint)))))
|
||||
(if symbol-string
|
||||
(multiple-value-bind (generate passthrough) (symbol-initial-terminals grammar (first symbol-string))
|
||||
(terminalset-union-f initial-terminals (terminalset-intersection passthrough-terminals generate))
|
||||
|
|
@ -1115,14 +1149,15 @@
|
|||
; Intern attributed or generic nonterminals in the production's lhs and rhs. Replace
|
||||
; (:- <terminal> ... <terminal>) or (:-- (<grammar-symbol> ... <grammar-symbol>) <terminal> ... <terminal>)
|
||||
; sublists in the rhs with lookahead-constraints and put these, in order, after the third element of
|
||||
; the returned list. Also replace :~ symbols with no-line-break-constraints.
|
||||
; the returned list. Also replace variant constraint symbols with variant-constraints.
|
||||
; The variant-constraint-names parameter should be a list of possible variant constraint symbols.
|
||||
; Return the resulting production source.
|
||||
(defun intern-production-source (grammar-parametrization production-source)
|
||||
(defun intern-production-source (grammar-parametrization variant-constraint-names production-source)
|
||||
(assert-type production-source (tuple (or user-nonterminal cons) (list (or user-grammar-symbol cons)) identifier))
|
||||
(let ((production-lhs-source (first production-source))
|
||||
(production-rhs-source (second production-source))
|
||||
(production-name (third production-source)))
|
||||
(if (or (consp production-lhs-source) (some #'consp production-rhs-source) (find ':~ production-rhs-source))
|
||||
(if (or (consp production-lhs-source) (some #'consp production-rhs-source) (intersection variant-constraint-names production-rhs-source))
|
||||
(multiple-value-bind (lhs-nonterminal lhs-arguments) (grammar-parametrization-intern grammar-parametrization production-lhs-source)
|
||||
(let ((rhs nil)
|
||||
(constraints nil)
|
||||
|
|
@ -1139,8 +1174,8 @@
|
|||
(push
|
||||
(make-lookahead-constraint pos (assert-non-null (rest lookaheads)) (assert-non-null (first lookaheads)))
|
||||
constraints)))
|
||||
((eq component-source ':~)
|
||||
(push (make-no-line-break-constraint pos) constraints))
|
||||
((member component-source variant-constraint-names)
|
||||
(push (make-variant-constraint pos component-source) constraints))
|
||||
(t
|
||||
(push (grammar-parametrization-intern grammar-parametrization component-source lhs-arguments) rhs)
|
||||
(incf pos))))
|
||||
|
|
@ -1160,36 +1195,45 @@
|
|||
; nonterminal can have attributes, thereby designating a specialization instead of a fully
|
||||
; generic production.
|
||||
;
|
||||
; variant-constraint-names should be a list of keywords that are variant-constraints instead of nonterminals
|
||||
;
|
||||
; A variant-generator is either nil or a function that takes a terminal and outputs a list of its variants.
|
||||
; Each variant is specified as a cons of:
|
||||
; A variant terminal
|
||||
; A list of names of variant constraints which exclude this variant terminal
|
||||
;
|
||||
; The rhs can also contain lookahead constraints of the form
|
||||
; (:- <terminal> ... <terminal>)
|
||||
; which indicate that the following terminal must not be one of the listed terminals. The form
|
||||
; (:-- (<grammar-symbol> ... <grammar-symbol>) <terminal> ... <terminal>)
|
||||
; does the same thing except that it prints the grammar-symbols instead of the terminals when
|
||||
; the production is printed. The form
|
||||
; :~
|
||||
; indicates that a line break is not allowed at the current position between terminals (this
|
||||
; constraint is currently ignored by the parser but does show up in printed grammars).
|
||||
; <constraint>
|
||||
; where <constraint> is a member of the variant-constraint-names list also represents a constraint on the following
|
||||
; terminal; that constraint excludes all variants that were returned by variant-generator along with this constraint.
|
||||
;
|
||||
; excluded-nonterminals-source is a list of nonterminals not used in the grammar. Productions,
|
||||
; excluded-nonterminals is a list of nonterminals not used in the grammar. Productions,
|
||||
; including productions expanded from generic productions, that have one of these nonterminals
|
||||
; on the lhs are ignored.
|
||||
(defun make-grammar (grammar-parametrization start-symbol grammar-source &optional excluded-nonterminals-source)
|
||||
(let ((interned-grammar-source
|
||||
(defun make-grammar (grammar-parametrization start-symbol grammar-source &key variant-constraint-names variant-generator excluded-nonterminals)
|
||||
(let ((variant-constraint-forbid-lists (mapcar #'list variant-constraint-names))
|
||||
(interned-grammar-source
|
||||
(mapcar #'(lambda (production-source)
|
||||
(intern-production-source grammar-parametrization production-source))
|
||||
(intern-production-source grammar-parametrization variant-constraint-names production-source))
|
||||
grammar-source))
|
||||
(rules (make-hash-table :test #'eq))
|
||||
(terminals-hash (make-hash-table :test *grammar-symbol-=*))
|
||||
(terminal-variants (make-hash-table :test *grammar-symbol-=*))
|
||||
(general-productions (make-hash-table :test #'equal))
|
||||
(production-number 0)
|
||||
(max-production-length 1)
|
||||
(excluded-nonterminals-hash (make-hash-table :test *grammar-symbol-=*))
|
||||
(lookahead-constraints nil))
|
||||
(constraints nil))
|
||||
|
||||
;Set up excluded-nonterminals-hash. The values of the hash table are either :seen or :unseen
|
||||
;depending on whether a production with the particular nonterminal has been seen yet.
|
||||
(dolist (excluded-nonterminal-source excluded-nonterminals-source)
|
||||
(setf (gethash (grammar-parametrization-intern grammar-parametrization excluded-nonterminal-source nil) excluded-nonterminals-hash)
|
||||
(dolist (excluded-nonterminal excluded-nonterminals)
|
||||
(setf (gethash (grammar-parametrization-intern grammar-parametrization excluded-nonterminal nil) excluded-nonterminals-hash)
|
||||
:unseen))
|
||||
|
||||
;Create the starting production: *start-nonterminal* ==> start-symbol
|
||||
|
|
@ -1243,6 +1287,16 @@
|
|||
(create-production production-lhs production-rhs production-constraints production-name)))))))
|
||||
|
||||
|
||||
(when variant-generator
|
||||
(dolist (terminal (hash-table-keys terminals-hash))
|
||||
(dolist (variant-and-constraints (funcall variant-generator terminal))
|
||||
(let ((variant (first variant-and-constraints)))
|
||||
(push variant (gethash terminal terminal-variants))
|
||||
(setf (gethash variant terminals-hash) t)
|
||||
(dolist (constraint (rest variant-and-constraints))
|
||||
(push variant (cdr (assoc constraint variant-constraint-forbid-lists))))))))
|
||||
|
||||
|
||||
;Change all values of the rules hash table to contain rule structures
|
||||
;instead of mere lists of rules. Also check that all referenced nonterminals
|
||||
;have been defined.
|
||||
|
|
@ -1254,8 +1308,8 @@
|
|||
(unless (gethash grammar-symbol rules)
|
||||
(error "Nonterminal ~S used but not defined" grammar-symbol))))
|
||||
(dolist (constraint (production-constraints rule-production))
|
||||
(push constraint constraints)
|
||||
(when (lookahead-constraint? constraint)
|
||||
(push constraint lookahead-constraints)
|
||||
(dolist (lookahead-terminal (lookahead-constraint-forbidden-terminals constraint))
|
||||
(unless (gethash lookahead-terminal terminals-hash)
|
||||
(warn "Lookahead terminal ~S not used in main grammar" lookahead-terminal)
|
||||
|
|
@ -1282,16 +1336,21 @@
|
|||
|
||||
(let ((terminals (coerce (cons *end-marker* (sorted-hash-table-keys terminals-hash))
|
||||
'simple-vector))
|
||||
(terminal-terminalsets (make-hash-table :test *grammar-symbol-=*))
|
||||
(nonterminals (coerce nonterminals-list 'simple-vector)))
|
||||
(dotimes (n (length terminals))
|
||||
(setf (gethash (svref terminals n) terminals-hash) n))
|
||||
(let ((terminal (svref terminals n)))
|
||||
(setf (gethash terminal terminals-hash) n)
|
||||
(pushnew terminal (gethash terminal terminal-variants))))
|
||||
(dotimes (n (length nonterminals))
|
||||
(setf (rule-number (gethash (svref nonterminals n) rules)) n))
|
||||
(let ((grammar (allocate-grammar
|
||||
:argument-attributes (grammar-parametrization-argument-attributes grammar-parametrization)
|
||||
:terminals terminals
|
||||
:nonterminals-list nonterminals-list
|
||||
:nonterminals nonterminals
|
||||
:nonterminals-list nonterminals-list
|
||||
:terminal-variants terminal-variants
|
||||
:terminal-terminalsets terminal-terminalsets
|
||||
:terminal-numbers terminals-hash
|
||||
:terminal-actions (make-hash-table :test *grammar-symbol-=*)
|
||||
:rules rules
|
||||
|
|
@ -1301,12 +1360,34 @@
|
|||
:n-productions production-number
|
||||
:items-hash (make-hash-table :test #'equal))))
|
||||
|
||||
;Compute the terminalsets in the lookahead-constraints.
|
||||
(dolist (lookahead-constraint lookahead-constraints)
|
||||
;Compute the terminalsets in the terminal-terminalsets.
|
||||
(dotimes (n (length terminals))
|
||||
(let ((terminal (svref terminals n))
|
||||
(terminalset *empty-terminalset*))
|
||||
(dolist (variant (terminal-variants grammar terminal))
|
||||
(terminalset-union-f terminalset (make-terminalset grammar variant)))
|
||||
(setf (gethash terminal terminal-terminalsets) terminalset)))
|
||||
|
||||
;Replace the cdr of each element of variant-constraint-forbid-lists with a terminalset of all
|
||||
;terminals not forbidden by that constraint.
|
||||
(dolist (constraint-and-forbidden-variants variant-constraint-forbid-lists)
|
||||
(let ((terminalset *full-terminalset*))
|
||||
(dolist (forbidden-terminal (lookahead-constraint-forbidden-terminals lookahead-constraint))
|
||||
(terminalset-difference-f terminalset (make-terminalset grammar forbidden-terminal)))
|
||||
(setf (lookahead-constraint-terminalset lookahead-constraint) terminalset)))
|
||||
(dolist (variant (rest constraint-and-forbidden-variants))
|
||||
(terminalset-difference-f terminalset (ash 1 (gethash variant terminals-hash)))
|
||||
(setf (rest constraint-and-forbidden-variants) terminalset))))
|
||||
|
||||
;Compute the terminalsets in the constraints.
|
||||
(dolist (constraint constraints)
|
||||
(cond
|
||||
((lookahead-constraint? constraint)
|
||||
(let ((terminalset *full-terminalset*))
|
||||
(dolist (forbidden-terminal (lookahead-constraint-forbidden-terminals constraint))
|
||||
(terminalset-difference-f terminalset (terminal-terminalset grammar forbidden-terminal)))
|
||||
(setf (constraint-terminalset constraint) terminalset)))
|
||||
((variant-constraint? constraint)
|
||||
(setf (constraint-terminalset constraint) (assert-non-null (cdr (assoc (variant-constraint-name constraint)
|
||||
variant-constraint-forbid-lists)))))
|
||||
(t (error "Unknown constraint ~S" constraint))))
|
||||
|
||||
;Compute the values of passthrough-terminals and initial-terminals in each rule.
|
||||
(do ((changed t))
|
||||
|
|
@ -1318,7 +1399,7 @@
|
|||
(new-passthrough-terminals *empty-terminalset*))
|
||||
(dolist (production (rule-productions rule))
|
||||
(multiple-value-bind (production-initial-terminals production-passthrough-terminals)
|
||||
(string-initial-terminals grammar (production-rhs production) (production-constraints production) 0)
|
||||
(string-initial-terminals grammar (production-rhs production) (production-constraints production) 0 nil)
|
||||
(terminalset-union-f new-initial-terminals production-initial-terminals)
|
||||
(terminalset-union-f new-passthrough-terminals production-passthrough-terminals)))
|
||||
(unless (terminalset-= new-initial-terminals (rule-initial-terminals rule))
|
||||
|
|
@ -1382,9 +1463,11 @@
|
|||
(format stream "~:@_ | ")))
|
||||
(pprint-indent :block 2 stream)
|
||||
(when details
|
||||
(format stream "~:@_Initial terminals: ~@_~@<~:[~;<epsilon> ~:_~]~{~W ~:_~}~:>"
|
||||
(not (terminalset-empty? (rule-passthrough-terminals rule)))
|
||||
(terminalset-list grammar (rule-initial-terminals rule)))))
|
||||
(format stream "~:@_Initial terminals: ~@_")
|
||||
(pprint-logical-block (stream nil)
|
||||
(unless (terminalset-empty? (rule-passthrough-terminals rule))
|
||||
(format stream "<epsilon> ~:_"))
|
||||
(print-terminalset grammar (rule-initial-terminals rule) stream))))
|
||||
(pprint-newline :mandatory stream))
|
||||
(pprint-exit-if-list-exhausted)
|
||||
(pprint-newline :mandatory stream)))
|
||||
|
|
@ -1433,6 +1516,18 @@
|
|||
(sort equivalences #'< :key #'(lambda (equivalence)
|
||||
(state-number (first equivalence))))))
|
||||
|
||||
; Call f on each state in the grammar, in order of state numbers.
|
||||
; f should take two parameters:
|
||||
; a state;
|
||||
; a hash table of terminal -> transition
|
||||
(defun all-state-transitions (f grammar)
|
||||
(let ((transitions-hash (make-hash-table :test *grammar-symbol-=*)))
|
||||
(dolist (state (grammar-states grammar))
|
||||
(dolist (transition-pair (state-transitions state))
|
||||
(setf (gethash (car transition-pair) transitions-hash) (cdr transition-pair)))
|
||||
(funcall f state transitions-hash)
|
||||
(clrhash transitions-hash))))
|
||||
|
||||
|
||||
;;; ------------------------------------------------------------------------------------------------------
|
||||
;;; YACC OUTPUT
|
||||
|
|
|
|||
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