APL/700

APL/700
Developer	Burroughs Corporation
Array model	flat without boxes
Index origin	0 or 1
Function styles	defined function
Numeric types	48-bit float
Unicode support	no
Platforms	B 6700/B 7700
Operating systems	Burroughs MCP
Documentation	User Reference Manual (pdf)
Influenced by	APL.SV

APL/700 was an APL implementation by Burroughs Corporation for their 700 series of mainframe computers. The language was mostly identical to that of APL.SV and its successors, but differed in a few details:

• The statement separator was a semicolon (;) rather than the conventional diamond ⋄ and statements in such a so-called list were evaluated from right to left, much as if the semicolon was the Left identity function (⊣).
• In primitive pairs with both a last and first axis version, for example / vs ⌿ and ⌽ vs ⊖, the first axis version would use the function axis syntax to indicate the applicable axis counted from the last axis rather than from the first axis. For example ⊖[1] was equivalent to ⌽ just like ⌽[1] was equivalent to ⊖.
• While in general reduction using scalar functions were supported by for arrays of a compatible data type (numeric or character), =/ and ≠/ did not support character data.
• APL/700 included modified assignment, but the pass-through value was the new value of the updated array.
• More set functions were included than even modern APLs have. In particular ⊂ and ⊂ were Subset and Superset, though not strict subset and superset, but rather as {∧/(,⍺)∊(,⍵)} and {∧/(,⍵)∊(,⍺)}. All the set functions except for Membership were defined in terms of the ravel of the arguments, and thus always returned a vector. Furthermore, Union (∪), Intersection (∩), and Set difference (~) returned only Unique elements, that is, a vector with no duplicates.
• Format ⍕ allowed an advanced formatting specification through a character left argument.
• Many additional quad names were available, including a set of two-letter system functions with all the combinations of S/R/Q (for Stop, Reset, Query) with T/S/M (Trace, Stop, Monitor), and character constants for control characters (⎕B, ⎕L, ⎕R, ⎕T, and ⎕N for Backspace, Linefeed, Return, Tab, and Null), the digits ⎕D, and the alphabet (⎕A).
• In a manner similar to, but more extensively than the much later APLX, APL/700 had primitive functions for file operations. In addition to ⍇ and ⍈ for read and write operations (as in APLX), it supported the following:
  • ⍍ to create, rename and change password for files, and ⍔ for deleting files.
  • ⍃ and ⍄ were used to read+pop and append components to the beginning and end of a file, respectively.
  • Equivalents of normal primitive functions for operations on component of files as if they were elements of a vectors: ⍐ and ⍗ acted like Take and Drop (↑ and ↓). ⌼ would Reverse and Rotate (⌽). ⍁ and ⍂ were Compress and Expand (/ and \).
  • ⍓ and ⍌ and ⍗ were used to hold, free, and relase a file.
  • ⌸ and ⍯ returned maps for non-null and null components, respectively.
  • ⌻ provided meta information about a file or the file system.