Placeholder Macro Language

optiSLang allows you to define macro expressions. Macro expressions create project placeholders composed of other user-defined placeholders or predefined constants. To define a macro expression:

  1. Create a new project placeholder.

  2. In the project placeholders table, double-click the Value cell of the placeholder.

  3. Select the Expression check box.

  4. Enter the macro expression in the text field to the right of the check box, or click Edit expression ( ) to open a separate dialog box with a larger text field.

Project placeholders are type-specific. A placeholder can be assigned to a project property only if they share the same data type. The macro language slightly differs between the types, but all types share the same rules for placeholder substitution, text concatenation, and literal escaping.

General Syntax

Placeholder Substitution

The syntax for placeholder substitution is $(placeholder_id). For example, to use the placeholder pl1 in a macro expression, the expression must contain $(pl1). This entry is substituted by the value of pl1 by the placeholder engine. Multiple placeholder substitutions can be used in a macro expression and a placeholder can be used multiple times.

The exception to this rule are numeric types. You do not need to add $ or enclosing parenthesis.

Text Concatenation

Text can be concatenated by appending text. No separators or operators are needed. For example, you have two placeholders pl1 and pl2 of type string with the values S and L respectively. The macro expression for creating the string optiSLang in this case is:

opti$(pl1)$(pl2)ang.

Literal escaping

Since the $ literal is used as a language literal, it must be escaped in case it is used as a plain string. The syntax for escaping is \.

Type-specific Syntax

String

String types require no specific syntax. The general syntax rules apply.

Example:

    Placeholders: pl1 := S;  pl2 := L
    Expression:   opti$(pl1)$(pl2)ang
    Result:       optiSLang

Path

Path types support a specific, platform-independent, separator literal for separating path entries. The path separator is /. The syntax rules for strings also apply.

Example:

    Placeholders:  model := ten_bar_truss
    Expression:    C:/samples_path/$(model)/$(model).s
    Result:        C:/samples_path/ten_bar_truss/ten_bar_truss.s

Split Path

Split path types support a specific literal for the path splitting position. The path splitting literal is |. The syntax rules for plain paths also apply.

Example:

    Placeholders:  model := ten_bar_truss
    Expression:    C:/samples_path/$(model)|$(model).s
    Result:        C:/samples_path/ten_bar_truss/ten_bar_truss.s 
    (Head: C:/samples_path/ten_bar_truss; Tail: ten_bar_truss.s)

Relative Split Path

Relative split path types support a specific prefix for defining the mode of relative split path. This prefix can be one of the following:

  • ABS: The path is considered to be absolute.

  • WD_REL: The split path tail is considered to be relative to the working directory.

  • PROJ_REL: The split path tail is considered to be relative to the project.

The prefix must be followed by a ; and a path or split path. The syntax rules for plain and split paths also apply.

Example:

    Placeholders:  model := ten_bar_truss
    Expression:    WD_REL;C:/samples_path/$(model)|$(model).s
    Result:        C:/samples_path/ten_bar_truss/ten_bar_truss.s 
    (Head: C:/samples_path/ten_bar_truss; Tail: ten_bar_truss.s; 
    ten_bar_truss.s considered to be relative to working dir)

String List

String list types support a specific separator literal for separating string entries. The string list entry separator is ;. The syntax rules for strings also apply.

Example:

    Placeholders: pl1 := hello;  pl2 := world
    Expression:   $(pl1);$(pl2);.
    Result:       String list with 3 entries [hello; world; .]

Numeric Types

The numeric types (Boolean, Integer, Unsigned integer, Real) support the optiSLang calculator expression syntax and their predefined objects and constants. For more information, see Using the Calculator.

Example:

    Placeholders: pl1 := 2;  pl2 := 1.5
    Expression:   sin(pl1) + pl2
    Result:       2.4093

Predefined Constants

The placeholder macro language contains predefined constants that can be used in macro expressions. The syntax rules for placeholder substitutions apply. The constants are:

  • PROJECT_DIR: location of the current optiSLang project

For numeric types, you can use the constants defined by the optiSLang calculator. For more information, see Using the Calculator.

Auto Completion

The placeholder macro expression line and text edits support auto completion for available placeholders and predefined constants. To use this feature, press Ctrl+Space to display the suggested placeholder names. Alternatively, you can start typing and the suggestions are automatically displayed when at least two characters of an available placeholder name have been typed.