- nv-macro-lexvar is a simple macro-tool, only one syntax
- cli tool, use a simple syntax
##lexvar(...) in your script
- to let you get/set lexical-variables(let,var,params) from outside
- to avoid using for/while/if-[elif]-else/switch
- npm install nv-macro-lexvar -g
Usage: nv_lexvar [options]
Options:
-i, --input input string ,default stdin
-o, --output output string,default stdout
-c, --compile compile the macro
-m, --macro_name `##${macro_name}` used in script,default is lexvar
-I, --IR list four basic funcions : sync_while,async_while,sync_if,async_if
-h, --help usage
nv-macro-lexvar# nv_lexvar -M
the default macro_name: lexvar
use it begin with two #: ##lexvar(...)
nv-macro-lexvar# nv_lexvar -S
.....
let i=1;let a =100; let b=999;.....
////-for example, you need to change
//// the lexical <a> AND <i> from outside handler <handler>
let ctx = ##lexvar(i,a);
////
handler(ctx)
.....
% nv_lexvar -c
////the source code
function swhile(
ctx,
condf =(ctx)=>ctx.i<5,
handler =(ctx)=>{ctx.rslt=ctx.rslt+ctx.i},
post =(ctx)=>{ctx.i=ctx.i+1}
) {
while(condf(ctx)) {
handler(ctx);
post(ctx);
}
return(ctx)
}
function tst(param) {
let i =0;
let rslt=i;
let ctx = ##lexvar(i,rslt); // capture lexical-variables for using from outside
swhile(ctx);
return(rslt)
}
//--------> press ctrl+D
function swhile(
ctx,
condf =(ctx)=>ctx.i<5,
handler =(ctx)=>{ctx.rslt=ctx.rslt+ctx.i},
post =(ctx)=>{ctx.i=ctx.i+1}
) {
while(condf(ctx)) {
handler(ctx);
post(ctx);
}
return(ctx)
}
function tst(param) {
let i = 0;
let rslt = i;
let ctx = (() => {
let ctx = {};
Object.defineProperty(ctx, 'i', {
get: () => i,
set: v => {
i = v;
}
});
Object.defineProperty(ctx, 'rslt', {
get: () => rslt,
set: v => {
rslt = v;
}
});
return ctx;
})();
swhile(ctx);
return rslt;
}
/*
> tst()
10
>
*/
function swhile(
ctx,
condf =(ctx)=>ctx.i<5,
handler =(ctx)=>{ctx.rslt=ctx.rslt+ctx.i},
post =(ctx)=>{ctx.i=ctx.i+1}
) {
while(condf(ctx)) {
handler(ctx);
post(ctx);
}
return(ctx)
}
function sif(
ctx,
entries=[
(ctx)=>ctx.param,(ctx)=>{console.log([ctx.rslt,':',ctx.param])}
],
else_handler=(ctx)=>console.log([ctx.param,':',ctx.rslt]),
) {
for(let i=0;i<entries.length;i=i+2) {
let condf = entries[i]
let handler = entries[i+1]
let cond = condf(ctx);
if(cond) {
handler(ctx)
return(ctx)
} else {}
}
ctx = else_handler(ctx);
return(ctx)
}
function tst(param) {
let i =0;
let rslt=i;
////
let ctx = ##lexvar(i,rslt); //capture lexical-variables <i AND rslt> for using from outside
swhile(ctx);
////
console.log("lex rslt changed:",rslt)
////
ctx = ##lexvar(param,rslt); //capture lexical-variables <param AND rslt> for using from outside
sif(ctx);
////
return(rslt)
}
////-------press ctrl+D
...... //generated code below
function tst(param) {
let i = 0;
let rslt = i; ////
/*##lexvar(i,rslt) generated code*/
let ctx = (() => {
let ctx = {};
Object.defineProperty(ctx, 'i', {
get: () => i,
set: v => {
i = v;
}
});
Object.defineProperty(ctx, 'rslt', {
get: () => rslt,
set: v => {
rslt = v;
}
});
return ctx;
})(); //capture lexical-variables <i AND rslt> for using from outside
swhile(ctx); ////
console.log("lex rslt changed:", rslt); ////
/*##lexvar(param,rslt) generated code*/
ctx = (() => {
let ctx = {};
Object.defineProperty(ctx, 'param', {
get: () => param,
set: v => {
param = v;
}
});
Object.defineProperty(ctx, 'rslt', {
get: () => rslt,
set: v => {
rslt = v;
}
});
return ctx;
})(); //capture lexical-variables <param AND rslt> for using from outside
sif(ctx); ////
return rslt;
}
/*
> tst(true)
lex rslt changed: 10
[ 10, ':', true ]
10
>
> tst(false)
lex rslt changed: 10
[ false, ':', 10 ]
10
>
*/
- sync while
- async while
- sync if
- async if
- MOST function could BE done with these four operations
- the ONLY exception is IF you want to implement goto-like,these four is NOT enough
swhile
-------
function swhile(
ctx,
condf,
handler,
post
) {
while(condf(ctx)) {
handler(ctx);
post(ctx);
}
return(ctx)
}
awhile
-------
async function awhile(
ctx,
condf,
handler,
post
) {
let cond = await condf(ctx)
while(cond) {
await handler(ctx);
await post(ctx);
cond = await condf(ctx);
}
return(ctx)
}
sif
-------
function sif(
ctx,
entries,
else_handler,
) {
for(let i=0;i<entries.length;i=i+2) {
let condf = entries[i];
let handler = entries[i+1];
let cond = condf(ctx);
if(cond) {
handler(ctx);
return(ctx)
} else {}
}
ctx = else_handler(ctx);
return(ctx)
}
aif
-------
async function aif(
ctx,
entries,
else_handler,
) {
for(let i=0;i<entries.length;i=i+2) {
let condf = entries[i];
let handler = entries[i+1];
let cond = await condf(ctx);
if(cond) {
await handler(ctx);
return(ctx)
} else {}
}
ctx = await else_handler(ctx);
return(ctx)
}