Overview
ISO/IEC 10206:1991 - Information technology - Programming languages - Extended Pascal - specifies the syntax and semantics of Extended Pascal. The standard defines requirements for a conforming processor and for conforming programs, contains an alphabetical index, and includes Annexes A–G for information only. The document formalizes language constructs, control flow, data types and input/output behavior to support portable implementations and consistent program semantics.
Key Topics
- Language syntax and semantics: Formal grammar and semantic rules for Extended Pascal statements and declarations.
- Iteration constructs: Detailed rules for traditional for‑statements and set‑member‑iteration (e.g.,
for c in hue1 do q(c)), including type compatibility, evaluation timing, and implementation-dependent member ordering.
- With‑statements: Semantics for
with lists that introduce field-designator and schema-discriminant identifiers within a localized scope, and rules for variable and constant access during execution.
- Threat analysis: Definition of when a statement “threatens” a variable-access (assignments, parameter passing, certain required procedures like
read, write, new, bind/unbind, etc.), with implications for aliasing and safety.
- Input/Output procedures: Precise behavior of
read, readln, and write on text files, including parameter syntax, pre/post assertions, character/number parsing rules, handling of strings (fixed and variable), and formatting (total width, fractional digits, floating‑point and fixed‑point output).
- Implementation-defined aspects: Areas where the standard leaves choices to implementers (e.g., order of set iteration, default formatting widths, exponent digit counts).
Applications
- Compiler and tool implementers: Use the standard to build conforming Extended Pascal compilers, interpreters, static analyzers and runtime libraries.
- Porting and legacy systems: Guide for maintaining or porting legacy Pascal code and ensuring consistent I/O and control-flow semantics across platforms.
- Education and language research: Reference for teaching language design, semantics, and formal specification of programming languages.
- Verification and static analysis: Basis for formal verification, code analysis, and proving program properties where precise semantics are required.
Who Should Use It
- Compiler engineers, language tool vendors, system integrators maintaining Pascal code, academics in programming‑language semantics, and organizations requiring documented, portable behavior of Extended Pascal programs.
Related standards
- Relevant to other Pascal family standards and language specifications defining core Pascal and extensions; useful for implementers targeting language conformance, portable I/O, and precise control‑flow semantics.
Keywords: ISO/IEC 10206, Extended Pascal, programming language standard, syntax and semantics, Pascal compiler, read write semantics, for-statement, with-statement, set-member-iteration.