Re: How to get last input line in MathLink mode?
- To: mathgroup at smc.vnet.net
- Subject: [mg116575] Re: How to get last input line in MathLink mode?
- From: Alexey <lehin.p at gmail.com>
- Date: Sun, 20 Feb 2011 05:26:33 -0500 (EST)
- References: <ijitrt$2r4$1@smc.vnet.net>
Here is the function I have developed for this:
In[1]:= getLastInput :=
Module[{num, f},
f = Function[{u, v}, {u /. {In -> num, HoldPattern -> First},
HoldComplete[v]}, HoldAllComplete];
First@Cases[
Block[{RuleDelayed = f}, DownValues[In]], {$Line - 1, x_} ->
x, {1}, 1]]
In[2]:= Evaluate[1 + 1]
Out[2]= 2
In[3]:= getLastInput
Out[3]= HoldComplete[Evaluate[1 + 1]]
The problem was that RuleDelayed partially evaluates its r.h.s. in
contradiction with the Documentation:
In[9]:= a:>Unevaluated[b] // FullForm
Out[9]//FullForm= RuleDelayed[a,b]
And I have got the answer to the question on InString in MathLink mode
from Todd Gayley (Wolfram Research):
> InString is only assigned when using EnterTextPacket, not
> EnterExpressionPacket. There is no string form of the input when
> sending EnterExpressionPacket (whose content is, by definition,
> already an expression).