Group:
parameters
Topic:
pattern matching
Topic:
pattern specification
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Summary
The classes within a pattern specification define sub-sequences and location indices which can be assigned to variables. Similarly leading and trailing sub-sequences can be assigned. Pattern component variables may be involved in the matching process, two pattern matches may define a subsequence between them. Once matching is completed, the pattern determines a structure with a pattern component variables as the components of that structure. (cbb 5/80)
Subtopic: pattern variables 
| QuoteRef: farbDJ1_1964 ;;24 all scans left to right so use pattern variables as pattern literals in the same search
| | QuoteRef: grisRE_1972 ;;30 on match, matched pattern to word eg text arb.word (arb any chars)
| | QuoteRef: sammJE_1969 ;;456 in pattern specification same name refers to same element in class
| | QuoteRef: memorex ;;2-10 variable symbols (eg &abc) are replaced by string form of value
| | Quote: Vulcan defines infix operator x/a.y.c where a. and .c receive pre and post context [»storEF_1970, OK]
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Subtopic: predefined variables
| QuoteRef: grisRE_1972 ;;31 within a pattern $word is replaced with each partial match
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Subtopic: positional variable
| QuoteRef: grisRE_1972 ;;31 @var matches null string, returns position within the string
| | QuoteRef: sammJE_1969 ;;428 numeric subscripts in pattern specification-- equals (.n), equals subscript of another constitute (.*j), greater than (.Gn or.G.*j , less than, and none (-.) eg c/.g25,.l35 tests the numeric range
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Subtopic: binding time
| QuoteRef: grisRE_1972 ;;34 when specifying a variable can use *variable to indicate don't evaluate until execute pattern search
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Subtopic: pattern operators
| Quote: Icon has scanning operations for upto©, many©, any©, find(s), match(s), &, | [»grisRE4_1980]
| | Quote: the 'upto(...)' operation in Icon, scans until the first occurrence of a letter [»grisRE4_1980]
| | Quote: the Icon scanning operation, upto©, is a generator that returns values until the expression succeeds [»grisRE4_1980]
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Subtopic: context matching
| Quote: Vulcan defines infix operator x/a.y.c where a. and .c receive pre and post context [»storEF_1970, OK]
| | Quote: Imp uses contextual string resolution; so p->q.(s).r picks and left and right context of s [»stepPD8_1974, OK]
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Subtopic: synonymns and noise words
Quote: TUTOR includes lists of synonymous words and lists of noise words to simplify analysis of student responses
[»schwJ_1980]
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Related Topics
Group: parameters (10 topics, 145 quotes)
Topic: pattern matching (42 items)
Topic: pattern specification
(15 items)
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