string-template-parser

String template parsing utilities.

- parseStringTemplate uses the default configuration (i.e. variable
start is marked by ${ and variable end by }, the escape character
is \ , a pipe is started with | and a pipe parameter starts after
a :, e.g. 'string ${var | pipe : parameter}').

- parseStringTemplateGenerator returns a string parsing function
that uses the supplied expressions from the configuration parameter
to parse the string.

- evaluateStringTemplate takes a string and a list of variables and
one of pipe functions and returns a string where the variables are
replaced with their values (transformed by the pipe functions if
necessary).

- evaluateParsedString takes a parsed string object generated by the
parseStringTemplate function and returns a concatenated string with
the variables replaced by the given values in the variable dictionary,
passed through the pipe functions if necessary. This function is useful
when not using the default parseStringTemplate function, but one
generated by passing a parameter to parseStringTemplateGenerator.
evaluateParsedString(parseStringTemplateGenerator()(input), ...args)
is equivalent to evaluateStringTemplate(input, ...args)

Usage

#### parseStringTemplate

``typescript
import { parseStringTemplate } from 'string-template-parser';

parseStringTemplate('a ${v1|p:param} b ${v2} c');
/* returns:
{
literals: ['a ', ' b ', ' c'],
variables: [
{ name: 'v1', pipes: [{ name: 'p', parameters: ['param'] }],
{ name: 'v2', pipes: []}
]
}
*/
`

#### parseStringTemplateGenerator

`typescript
import { parseStringTemplateGenerator } from 'string-template-parser';

const parseAngularStringTemplate = parseStringTemplateGenerator({
VARIABLE_START: /^\{\{\s*/,
VARIABLE_END: /^\s*\}\}/
});

parseAngularStringTemplate('a {{v1|p:param}} b {{v2}} c');
/* returns:
{
literals: ['a ', ' b ', ' c'],
variables: [
{ name: 'v1', pipes: [{ name: 'p', parameters: ['param'] }],
{ name: 'v2', pipes: []}
]
}
*/
`

#### evaluateStringTemplate

`typescript
import { evaluateStringTemplate } from 'string-template-parser';

evaluateStringTemplate(
'x ${a|upper} y',
{a: 'string'},
{upper: value => value.toUpperCase()}
);
// returns 'x STRING y'
`

#### evaluateParsedString

`typescript
import {
parseStringTemplateGenerator,
evaluateParsedString
} from 'string-template-parser';

const parseAngularStringTemplate = parseStringTemplateGenerator({
VARIABLE_START: /^\{\{\s*/,
VARIABLE_END: /^\s*\}\}/
});

evaluateParsedString(
parseAngularStringTemplate('x {{a|upper}} y'),
{a: 'string'},
{upper: value => value.toUpperCase()}
);
// returns 'x STRING y'
``