WOLFRAM

Wolfram Language & System Documentation Center

"HeldSemanticExpression" (Interpreter Type)

Wolfram Language expression given in natural language.

Details

Allowed Forms

  • Any free-form linguistics that represent a valid Wolfram Language expression.

Restriction Specifications

Interpretation

Examples

Basic Examples  (7)

Interpret expressions and avoid evaluation:

Wolfram Language code: Interpreter["HeldSemanticExpression"]["int sin(x) from -pi to pi"]
Wolfram Language code: Interpreter["HeldSemanticExpression"]["author of Pride and Prijudice"]

Find out Wolfram Language representations of natural-language queries:

Wolfram Language code: Interpreter["HeldSemanticExpression"]["second derivative of log x"]

No evaluation is attempted when matching the choices:

Wolfram Language code: Interpreter[Restricted["HeldSemanticExpression", {{1, 2, 3, 4}}]]["two plus one"]
Wolfram Language code: Interpreter[Restricted["HeldSemanticExpression", {{2, HoldComplete[2 + 1]}}]]["two plus one"]

By default, all symbols are allowed. Restrict to a list of allowed symbols:

Wolfram Language code: Interpreter[Restricted["HeldSemanticExpression", {Plus, Times, Equal}]]["6*4==16+8"]
Wolfram Language code: Interpreter[Restricted["HeldSemanticExpression", {Plus, Times, Equal}]]["6/4==16+8"]

By default, new symbols are created in $Context, but a custom context can be specified:

Wolfram Language code: Interpreter[Restricted["HeldSemanticExpression", All, Automatic, Automatic]]["y + 2"] Context[y]
Wolfram Language code: Interpreter[Restricted["HeldSemanticExpression", All, Automatic, "mycontext`"]]["j + 2"] Context[j]

Specify contexts for the allowed and output symbols:

Wolfram Language code: mycontext`b = 10; Interpreter[Restricted["HeldSemanticExpression", Automatic, {"mycontext`", "System`"}, "mycontext`"]]["a+b"] Context[a]

Prevent the creation of any new symbol:

Wolfram Language code: Interpreter[Restricted["HeldSemanticExpression", Automatic, Automatic, None]]["cos(pi)"]
Wolfram Language code: Interpreter[Restricted["SemanticExpression", Automatic, Automatic, None]]["cos(x)"]