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Contents |
A.1.0 General
This document is derived from the normative Annex A part of the TTCN3 Standard (Methods For Testing and Specification (MTS) - TTCN-3 - Part1: TTCN-3 Core language - ETSI ES 201 873-1 v3.1.1 (2005-06) ). This version defines the language subset which is supported by the Go4IT platform.
This annex defines the syntax of TTCN-3 using extended BNF (henceforth just called BNF).
A.1.1 Conventions for the syntax description
Table A.1 defines the metanotation used to specify the extended BNF grammar for TTCN-3.
| ::= | is defined to be |
| abc xyz | abc followed by xyz |
| │ | alternative |
| [abc] | 0 or 1 instances of abc |
| {abc} | 0 or more instances of abc |
| {abc}+ | 1 or more instances of abc |
| (...) | textual grouping |
| Abc | the non-terminal symbol abc |
| "abc" | a terminal symbol abc |
Go4IT grammar is defined as a subset of the TTCN-3 grammar. The keywords and that will not be implemented in Go4IT is red marked.
A.1.2 Statement terminator symbols
In general all TTCN-3 language constructs (i.e. definitions, declarations, statements and operations) are terminated with a semi-colon (;). The semi-colon is optional if the language construct ends with a right-hand curly brace (}) or the following symbol is a right-hand curly brace (}), i.e. the language construct is the last statement in a block of statements, operations and declarations.
A.1.3 Identifiers
TTCN-3 identifiers are case sensitive and may only contain lowercase letters (a-z) uppercase letters (A-Z) and numeric digits (0-9). Use of the underscore ( _ ) symbol is also allowed. An identifier shall begin with a letter (i.e. not a number and not an underscore).
A.1.4 Comments
Comments written in free text may appear anywhere in a TTCN-3 specification. Block comments shall be opened by the symbol pair /* and closed by the symbol pair */.
EXAMPLE 1:
/* This is a block comment
spread over two lines */
Block comments shall not be nested.
/* This is not /* a legal */ comment */
Line comments shall be opened by the symbol pair // and closed by a <_newline_>.
EXAMPLE 2:
// This is a line comment // spread over two lines
Line comments may follow TTCN-3 program statements but they shall not be embedded in a statement.
EXAMPLE 3:
// The following is not legal const // This is MyConst integer MyConst := 1;
// The following is legal const integer MyConst := 1; // This is MyConst
A.1.5 TTCN-3 terminals
TTCN-3 terminal symbols and reserved words are listed in tables A.2 and A.3.
| Begin/end block symbols | { } |
| Begin/end list symbols | ( ) |
| Alternative symbols | [ ] |
| To symbol (in a range) | .. |
| Line comments and Block comments | /* */ // |
| Line/statement terminator symbol | ; |
| Arithmetic operator symbols | + / - |
| String concatenation operator symbol | & |
| Equivalence operator symbols | != == >= <= |
| String enclosure symbols | " ' |
| Wildcard/matching symbols | ? * |
| Assignment symbol | := |
| Communication operation assignment | -> |
| Bitstring, hexstring and Octetstring values | B H O |
| Float exponent | E |
The predefined function identifiers defined in table 10 and described in annex C shall also be treated as reserved words.
- All “black character” keywords and associated rules and mechanisms are part of the Go4IT platform
- All “red character” keywords and associated rules will not be developed in Go4IT platform (not needed by the supported test suites)
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action, activate, address, alive, all, alt, altstep, and, and4b, any, anytype |
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bitstring, boolean |
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case, call, catch, char, charstring, check, clear, complement, component, connect, const, control, create |
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deactivate, default, disconnect, display, do, done |
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else, encode, enumerated, error, except, exception, execute, extends, extension, external |
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fail, false, float, for, from, function |
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getverdict, getcall, getreply, goto, group |
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hexstring |
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if, ifpresent, import, in, inconc, infinity, inout, integer, interleave |
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kill, killed |
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label, language, length, log |
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map, match, message, mixed, mod, modifies, module, modulepar, mtc |
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noblock, none, not, not4b, nowait, null |
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octetstring, of, omit, on, optional, or, or4b, out, override |
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param, pass, pattern, port, procedure, permutation |
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raise, read, receive, record, recursive (deprecated), rem, repeat, reply, return, running, runs |
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select, self, send, sender, set, setverdict, signature, start, stop, subset, superset, system |
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template, testcase, timeout, timer, to, trigger, true, type |
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union, universal, unmap |
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value, valueof, var, variant, verdicttype |
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while, with |
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xor, xor4b |
The TTCN-3 terminals listed in table A.3 shall not be used as identifiers in a TTCN-3 module. These terminals shall be written in all lowercase letters.