FUNCTIONUnder review

Eval

Eval( bBloco, [xVariavel] ) --> xRetorno

Executes a block and returns its last expression.

EvalAdvPL

01 · OVERVIEW

Overview

Eval executes the supplied block rather than merely inspecting it. Its return can be any type, depending on the last evaluated expression. Arguments are passed under the call contract. The example uses a pure calculation block and fixed input without macro-compiling external text or accessing tables. Check effects before evaluating interface or database callbacks. (TOTVS, n.d., ref. 1)

02 · SYNTAX

Syntax

Eval( bBloco, [xVariavel] ) --> xRetorno

Parameters

bBloco

Code blockRequired

Block to execute.

xVariavel

AnyOptional

Argument supplied to the block.

Return value

Value of the block’s last expression.

03 · PRACTICAL EXAMPLE

Commented example

#Include "Protheus.ch"

User Function Ed370()
    Local bDouble := {|nValue| nValue * 2}
    // Local calculation only, without external effects.
    ConOut(cValToChar(Eval(bDouble, 4)))
Return Nil

Expected result

Expected result: 8. Under review: editorial example neither compiled nor run in Protheus. Check includes, release, RDD and context before testing.

BEST PRACTICES

Validate block input and understand dependencies before execution.
Under review: editorial example neither compiled nor run in Protheus. Check includes, release, RDD and context before testing.