statement

#statement

##Syntax A statement is one of:

(a) assignmentStatement % variableReference := expn (b) openStatement % open � (c) closeStatement % close � (d) putStatement % put � (e) getStatement % get � (f) readStatement % read � (g) writeStatement % write � (h) seekStatement % seek � (i) tellStatement % tell � (j) forStatement % for � end for (k) loopStatement % loop � end loop (l) exit [ when trueFalseExpn ] (m) ifStatement % if � end if (n) caseStatement % case � end case (o) assert trueFalseExpn (p) begin statementsAndDeclarations end (q) procedureCall % procedureId [(parameters)] (r) return (s) result expn (t) new [ collectionId , ] pointerVariableReference (u) free [ collectionId , ] pointerVariableReference (v) tag unionVariableReference , expn (w) forkStatement % fork � (x) signal variableReference (y) wait variableReference [ , expn ] (z) pause expn (aa) quit [ guiltyParty ] [ : quitReason ] (bb) unchecked (cc) checked

##Description A statement (or command) causes a particular action, for example, the putStatement:

outputs Hello. See the descriptions of the individual statements for explanations of their actions. Each statement can optionally by followed by a semicolon (;).

    put "Hello"

##Example

    width := 24         % Assignment statement
    put "Hello world"   % Put statement
    exit when i = 100       % Exit statement
    assert width < 320  % Assert statement

##Details You can use a result statement only in a function. You can use a return statement only to terminate a procedure or the main program (but not to terminate the initialization of a module). See also result and return.

There are a number of predefined procedures, such as drawline, which are not listed as statements above. These are considered procedure calls, which is one form of statement.