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nfe
Non-deterministic finite automata expression
Module DescriptionThe nfe module implements an expression in a non-deterministic finite automata. An expression is a concatenation, repeation or alteration of non-deterministic finite automata states nfs. An not yet fully built expression consists of two cells on the stack: a list with the non resolved out states and a list of nfs states.<br> The code is based on the Thompson NFA algorithm published by Russ Cox. Module WordsExpression structurenfe% ( -- n ) Get the required space for a nfe expression Expression creation, initialisation and cleanupnfe-init ( nfe -- ) Initialise the expressionnfe+free-expression ( nfe -- ) Free all states in the subexpression recursivenfe-(free) ( nfe -- ) Free the internal, private variables from the heapnfe-create ( "<spaces>name" -- ; -- nfe ) Create a named expression in the dictionarynfe-new ( -- nfe ) Create a new expression on the heapnfe-free ( nfe -- ) Free the expression from the heap Member wordsnfe-visit++ ( nfe -- n ) Increment the visit number in the expression, return the visit numbernfe-level+@ ( nfe -- n ) Increment and return the paren levelnfe-visit@ ( nfe -- n ) Get the current visit numbernfe-expression@ ( nfe -- a-addr ) Get the list of states in the expression or nilnfe-states@ ( nfe -- n ) Get the number of states in the expressionnfe-parens@ ( nfe -- n ) Get the number of parens in the expression Expression building wordsnfe-clear ( nfe -- ) Clear the expressionnfe-single ( x n nfe -- nfs1 nfs2 ) Start an expression, nfs2 nfs1, with a single new state nfs1 with data x and type nnfe-concat ( nfs1 nfs2 nfs3 nfs4 nfe -- nfs5 nfs6 ) Concat the two expressions, return the outs nfs5 and start nfs6nfe-paren ( nfs1 nfs2 n nfe -- nfs3 nfs4 ) Paren the expression with level n, return the new outs nf3 and start nfs4nfe-alternation ( nfs1 nfs2 nfs3 nfs4 nfe -- nfs5 nfs6 ) Make an alternation [|] of two expressions, return the new outs nfs5 and start nfs6nfe-zero-or-one ( nfs1 nfs2 nfe -- nfs3 nfs4 ) Repeat the expression one or zero ? times, return the new start outs nfs3 and start nfs4nfe-zero-or-more ( nfs1 nfs2 nfe -- nfs3 nfs4 ) Repeat the expression zero or more * times, return the new outs nfs3 and start nfs4nfe-one-or-more ( nfs1 nfs2 nfe -- nfs3 nfs4 ) Repeat the expression one or more + times, return the new outs nfs3 and start nfs4nfe-close ( nfs1 nfs2 nfe -- nfs3 ) Close the expression by adding the match state, return the start nfs3 Matching wordsnfe-match? ( c-addr u flag nfe -- flag ) Match a string c-addr u, with the flag indicating case insensitive match, return the match resultnfe-search ( c-addr u flag nfe -- n ) Search in the string c-addr u for a match, with the flag indicating case insensitive match, return the first offset for a match, or -1 for no matchnfe-result ( n1 nfe -- n2 n3 ) Get the match result of the n1th grouping, return match start n3 and end n2 Inspectionnfe-dump ( nfe -- ) Dump the expression Generated by ofcfrth-0.10.0 |
