BCPL - Basic CPL. Richards 1969. British systems language, a descendant
of CPL and the inspiration for B and C. BCPL is low-level, typeless and
block-structured, and provides only one-dimensional arrays. Case is not
significant, but conventionally reserved words begin with a capital.
Flow control: If-Then, Test-Then-Else, Unless-Do, While-Do, Until-Do,
Repeat, Repeatwhile, Repeatuntil, For-to-By-Do, Loop, Break and
Switchon-Into-Case-Default-Endcase. BCPL has conditional expressions,
pointers, and manifest constants. BCPL had both procedures: Let foo(bar)
Be command and functions: Let foo(bar) = expression. Valof
$(..Resultis..$) causes a compound command to produce a value. Parameters
are call-by-value.
Program segments communicate via the global vector where system and
user variables are stored in fixed numerical locations in a single array.
BCPL was used to implement the TRIPOS OS, which was subsequently
reincarnated as AmigaDOS. "BCPL - The Language and its Compiler", Martin
Richards & Colin Whitby-Stevens, Cambridge U Press 1979. (See OCODE,
INTCODE).
Oxford BCPL differed slightly: Test-Ifso-Ifnot, and section brackets in
place of $( $).
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