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Syntax Resolution

IP.com Disclosure Number: IPCOM000075573D
Original Publication Date: 1971-Oct-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 4 page(s) / 18K

Publishing Venue

IBM

Related People

Bandat, KF: AUTHOR [+6]

Abstract

All control language statements conform to one general syntactic structure. This means that rules for interpreting control language are the same for all control language statements. These rules can be divided into two distinct groups: 1) verb resolution 2) parameter resolution. The following tables summarize the general steps and use identifying numerals and characters corresponding to their use with the steps and rules that follow: Syntax Pre-Processing (2) Parse statement into parts Label-Field Verb-Field Parameter-Field Verb Resolution Processing (3.1) If verb not fully qualified then if no implicit qualifier known then add qualifier "system" (3.

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Syntax Resolution

All control language statements conform to one general syntactic structure. This means that rules for interpreting control language are the same for all control language statements. These rules can be divided into two distinct groups: 1) verb resolution 2) parameter resolution. The following tables summarize the general steps and use identifying numerals and characters corresponding to their use with the steps and rules that follow: Syntax Pre- Processing (2) Parse statement into parts Label-Field Verb-Field Parameter-Field Verb Resolution Processing (3.1) If verb not fully qualified then if no implicit qualifier known then add qualifier "system" (3.2) Else add implicit qualifier (4) Process verb synonyms (5,6) Add "call" or "include" if required (7) Check subset to see if verb legal (8) Process substitution variables Parameter Resolution Processing (9) Parse parameter-field into parts: Positional-Parameters Keyword- Parameters (10) Process Hybrid Parameters (A) Process Keyword Synonyms
(11) Process "simple" defaults (12) Process "Model" defaults until no more models exist (E) Process substitution variables from defaults (13) Process implications Check keyword subset to see if keywords are legal.

First consider a general logical outline of the rules for verb resolution

1. The syntactic interpretation of a control language statement starts on the "prime form" of the statement. The prime form of a statement is defined to be: label-field label-delimiter verb-field verb-delimiter parameter-field statement-end- delimiter.

2. The statement is parsed into the above parts by finding each of the delimiters in turn.

3. The character-string in the verb-field is investigated for qualification. The control language verbs are represented in full syntactic form as "qualifier verb". This is called the fully qualified verb name. A verb may be written explicitly in its fully qualified form "qualifier verb", or in the implicit form "verb".

3.1 If the qualifier is implicit, the current qualification defined for that verb is applied to make a fully qualified verb name.

3.2 If the qualifier is implicit and there is no defined qualifier for that verb, the qualifier "system" is applied to make a fully qualified verb name.

4. The fully qualified verb name is then compared with the current set of synonym specifications. If it is a synonym for another fully qualified verb name, then this new name replaces the verb field. This synonym replacement is iterated until no more synonyms are found for the verb field.

5. If the verb name is actually the name of a problem program, an implicit CALL is required; the verb field becomes "CALL", and the original verb field is attached to the beginning of the parameter field.

6. If the verb name is really the name of a procedure, the verb field becomes "INCLUDE", and the old verb is attached to the beginning of the parameter field.

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7. Current subset specifications are checked to see whether...