☜	$QUERY 1990 Version of ANSI Standard					☞

2.2.7.13 $Query

$Q[UERY] ( glvn )

See 2.2.2.2 for the definition of glvn.

Let glvn₁ = ^A(i₁, i₂, ..., i_p) and glvn₂ = ^A(j₁, j₂, ..., j_q)

Then a collating relation exists between glvn₁ and glvn₂. Glvn₂ is said to follow glvn₁ when for any pair (i_k, j_k) when:

1. p < q and i_k = j_k for all k in the range (0 < k '> p).
   or
2. p = 0 and q > 0.
   or
3. k > 0 and k '> min(p, q) and
   there exists some i_k '= j_k and
   no n exists with 0 < n < k and i_n '= j_n and
   the function CO(i_k, j_k), as defined in 2.2.7 (definition of $Order), is equal to j_k.
   In less formal terms, when the first index that is different, collates in glvn₂ after the corresponding one in glvn₁.

For the purpose of this discussion a function CQ(glvn₁, glvn₂) is defined that would yield glvn₂ when, according to the above definition, glvn₂ would be said to follow glvn₁.

See 2.3 for the definition of expr.

A namevalue has the syntax of a glvn with the following restrictions:

1. The glvn is not a naked reference.
2. Each subscript whose value has the form of a number as defined in 2.2.3.1 appears as a numlit, spelled as its numeric interpretation.
3. Each subscript whose value does not have the form of a number as defined in 2.2.3.1 appears as a sublit, defined as follows:

   sublit

   ::=

   "

   │ │ │

   " " ubnonquote

   │ │ │

   ...

   "

   where subnonquote is defined as follows:

   subnonquote

   ::=

   any character valid in a subscript, excluding the quote symbol.

Then the value of the function $Query can be defined as follows:

• the value of $Query(glvn₁) is a namevalue that conforms to glvn₂ if and only if:
     CQ (glvn₁, glvn₂) = glvn₂
• and no glvn₃ exists so that
     CQ (glvn₁, glvn₃) = glvn₃
• and
     CQ (glvn₃, glvn₂) = glvn₂
• the value of $Query(glvn₁) will be the empty string when no glvn₂ exists so that
     CQ (glvn₁, glvn₂) = glvn₂

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Copyright © Examples: 1995-2024 Ed de Moel;
Copyright © Annotations: 2003-2008 Jacquard Systems Research
Copyright © Annotations: 2008-2024 Ed de Moel.

This page most recently updated on 15-Nov-2023, 13:11:39.

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