refactor($parse): Create idents lazily

[lgalfaso]

Create the ident functions lazily as these are not used for filters not object literal properties
The generated functions that are not used can cause issues with some browsers

Closes #9131

Note: This may have cause some performance improvements

[caitp]

were you actually able to reproduce the issues they were talking about?

[lgalfaso]

@caitp This is what I did:

• Went to the plunker from Potential usage of reserved keywords in Parser.getterFn #9131 and put a breakpoint at

// parse.js@934

var evaledFnGetter = new Function('s', 'l', code); // s=scope, l=locals

We were generating a function where

code === 'if(s == null) return undefined;
s=((l&&l.hasOwnProperty("in"))?l:s).in;
return s;'

• Created this patch, did the same and we were not creating a function like this

(we were creating one for animate, but that is something different)

[jbedard]

Could this line change to

primary = CONSTANTS[token.text] || getterFn(token.text, this.options, this.text);

...and avoid the lazyFn + fn setup above?

[lgalfaso]

a primary can be an identifier or a constant, so it would look like something like this

primary = token.fn || token.identifier && (CONSTANTS[token.text] || getterFn(token.text, this.options, token.expression));

where expression and identifier need to be added

[jbedard]

The expression text already exists (this.text in Parser), I guess the identifier flag and token.fn || would be needed though.

[lgalfaso]

you are right, we already have expression

[lgalfaso]

closing this in favor of #9431