Migrate to new swagger docs generation (#18)
This commit is contained in:
406
vendor/github.com/alecthomas/template/doc.go
generated
vendored
Normal file
406
vendor/github.com/alecthomas/template/doc.go
generated
vendored
Normal file
@ -0,0 +1,406 @@
|
||||
// Copyright 2011 The Go Authors. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
/*
|
||||
Package template implements data-driven templates for generating textual output.
|
||||
|
||||
To generate HTML output, see package html/template, which has the same interface
|
||||
as this package but automatically secures HTML output against certain attacks.
|
||||
|
||||
Templates are executed by applying them to a data structure. Annotations in the
|
||||
template refer to elements of the data structure (typically a field of a struct
|
||||
or a key in a map) to control execution and derive values to be displayed.
|
||||
Execution of the template walks the structure and sets the cursor, represented
|
||||
by a period '.' and called "dot", to the value at the current location in the
|
||||
structure as execution proceeds.
|
||||
|
||||
The input text for a template is UTF-8-encoded text in any format.
|
||||
"Actions"--data evaluations or control structures--are delimited by
|
||||
"{{" and "}}"; all text outside actions is copied to the output unchanged.
|
||||
Actions may not span newlines, although comments can.
|
||||
|
||||
Once parsed, a template may be executed safely in parallel.
|
||||
|
||||
Here is a trivial example that prints "17 items are made of wool".
|
||||
|
||||
type Inventory struct {
|
||||
Material string
|
||||
Count uint
|
||||
}
|
||||
sweaters := Inventory{"wool", 17}
|
||||
tmpl, err := template.New("test").Parse("{{.Count}} items are made of {{.Material}}")
|
||||
if err != nil { panic(err) }
|
||||
err = tmpl.Execute(os.Stdout, sweaters)
|
||||
if err != nil { panic(err) }
|
||||
|
||||
More intricate examples appear below.
|
||||
|
||||
Actions
|
||||
|
||||
Here is the list of actions. "Arguments" and "pipelines" are evaluations of
|
||||
data, defined in detail below.
|
||||
|
||||
*/
|
||||
// {{/* a comment */}}
|
||||
// A comment; discarded. May contain newlines.
|
||||
// Comments do not nest and must start and end at the
|
||||
// delimiters, as shown here.
|
||||
/*
|
||||
|
||||
{{pipeline}}
|
||||
The default textual representation of the value of the pipeline
|
||||
is copied to the output.
|
||||
|
||||
{{if pipeline}} T1 {{end}}
|
||||
If the value of the pipeline is empty, no output is generated;
|
||||
otherwise, T1 is executed. The empty values are false, 0, any
|
||||
nil pointer or interface value, and any array, slice, map, or
|
||||
string of length zero.
|
||||
Dot is unaffected.
|
||||
|
||||
{{if pipeline}} T1 {{else}} T0 {{end}}
|
||||
If the value of the pipeline is empty, T0 is executed;
|
||||
otherwise, T1 is executed. Dot is unaffected.
|
||||
|
||||
{{if pipeline}} T1 {{else if pipeline}} T0 {{end}}
|
||||
To simplify the appearance of if-else chains, the else action
|
||||
of an if may include another if directly; the effect is exactly
|
||||
the same as writing
|
||||
{{if pipeline}} T1 {{else}}{{if pipeline}} T0 {{end}}{{end}}
|
||||
|
||||
{{range pipeline}} T1 {{end}}
|
||||
The value of the pipeline must be an array, slice, map, or channel.
|
||||
If the value of the pipeline has length zero, nothing is output;
|
||||
otherwise, dot is set to the successive elements of the array,
|
||||
slice, or map and T1 is executed. If the value is a map and the
|
||||
keys are of basic type with a defined order ("comparable"), the
|
||||
elements will be visited in sorted key order.
|
||||
|
||||
{{range pipeline}} T1 {{else}} T0 {{end}}
|
||||
The value of the pipeline must be an array, slice, map, or channel.
|
||||
If the value of the pipeline has length zero, dot is unaffected and
|
||||
T0 is executed; otherwise, dot is set to the successive elements
|
||||
of the array, slice, or map and T1 is executed.
|
||||
|
||||
{{template "name"}}
|
||||
The template with the specified name is executed with nil data.
|
||||
|
||||
{{template "name" pipeline}}
|
||||
The template with the specified name is executed with dot set
|
||||
to the value of the pipeline.
|
||||
|
||||
{{with pipeline}} T1 {{end}}
|
||||
If the value of the pipeline is empty, no output is generated;
|
||||
otherwise, dot is set to the value of the pipeline and T1 is
|
||||
executed.
|
||||
|
||||
{{with pipeline}} T1 {{else}} T0 {{end}}
|
||||
If the value of the pipeline is empty, dot is unaffected and T0
|
||||
is executed; otherwise, dot is set to the value of the pipeline
|
||||
and T1 is executed.
|
||||
|
||||
Arguments
|
||||
|
||||
An argument is a simple value, denoted by one of the following.
|
||||
|
||||
- A boolean, string, character, integer, floating-point, imaginary
|
||||
or complex constant in Go syntax. These behave like Go's untyped
|
||||
constants, although raw strings may not span newlines.
|
||||
- The keyword nil, representing an untyped Go nil.
|
||||
- The character '.' (period):
|
||||
.
|
||||
The result is the value of dot.
|
||||
- A variable name, which is a (possibly empty) alphanumeric string
|
||||
preceded by a dollar sign, such as
|
||||
$piOver2
|
||||
or
|
||||
$
|
||||
The result is the value of the variable.
|
||||
Variables are described below.
|
||||
- The name of a field of the data, which must be a struct, preceded
|
||||
by a period, such as
|
||||
.Field
|
||||
The result is the value of the field. Field invocations may be
|
||||
chained:
|
||||
.Field1.Field2
|
||||
Fields can also be evaluated on variables, including chaining:
|
||||
$x.Field1.Field2
|
||||
- The name of a key of the data, which must be a map, preceded
|
||||
by a period, such as
|
||||
.Key
|
||||
The result is the map element value indexed by the key.
|
||||
Key invocations may be chained and combined with fields to any
|
||||
depth:
|
||||
.Field1.Key1.Field2.Key2
|
||||
Although the key must be an alphanumeric identifier, unlike with
|
||||
field names they do not need to start with an upper case letter.
|
||||
Keys can also be evaluated on variables, including chaining:
|
||||
$x.key1.key2
|
||||
- The name of a niladic method of the data, preceded by a period,
|
||||
such as
|
||||
.Method
|
||||
The result is the value of invoking the method with dot as the
|
||||
receiver, dot.Method(). Such a method must have one return value (of
|
||||
any type) or two return values, the second of which is an error.
|
||||
If it has two and the returned error is non-nil, execution terminates
|
||||
and an error is returned to the caller as the value of Execute.
|
||||
Method invocations may be chained and combined with fields and keys
|
||||
to any depth:
|
||||
.Field1.Key1.Method1.Field2.Key2.Method2
|
||||
Methods can also be evaluated on variables, including chaining:
|
||||
$x.Method1.Field
|
||||
- The name of a niladic function, such as
|
||||
fun
|
||||
The result is the value of invoking the function, fun(). The return
|
||||
types and values behave as in methods. Functions and function
|
||||
names are described below.
|
||||
- A parenthesized instance of one the above, for grouping. The result
|
||||
may be accessed by a field or map key invocation.
|
||||
print (.F1 arg1) (.F2 arg2)
|
||||
(.StructValuedMethod "arg").Field
|
||||
|
||||
Arguments may evaluate to any type; if they are pointers the implementation
|
||||
automatically indirects to the base type when required.
|
||||
If an evaluation yields a function value, such as a function-valued
|
||||
field of a struct, the function is not invoked automatically, but it
|
||||
can be used as a truth value for an if action and the like. To invoke
|
||||
it, use the call function, defined below.
|
||||
|
||||
A pipeline is a possibly chained sequence of "commands". A command is a simple
|
||||
value (argument) or a function or method call, possibly with multiple arguments:
|
||||
|
||||
Argument
|
||||
The result is the value of evaluating the argument.
|
||||
.Method [Argument...]
|
||||
The method can be alone or the last element of a chain but,
|
||||
unlike methods in the middle of a chain, it can take arguments.
|
||||
The result is the value of calling the method with the
|
||||
arguments:
|
||||
dot.Method(Argument1, etc.)
|
||||
functionName [Argument...]
|
||||
The result is the value of calling the function associated
|
||||
with the name:
|
||||
function(Argument1, etc.)
|
||||
Functions and function names are described below.
|
||||
|
||||
Pipelines
|
||||
|
||||
A pipeline may be "chained" by separating a sequence of commands with pipeline
|
||||
characters '|'. In a chained pipeline, the result of the each command is
|
||||
passed as the last argument of the following command. The output of the final
|
||||
command in the pipeline is the value of the pipeline.
|
||||
|
||||
The output of a command will be either one value or two values, the second of
|
||||
which has type error. If that second value is present and evaluates to
|
||||
non-nil, execution terminates and the error is returned to the caller of
|
||||
Execute.
|
||||
|
||||
Variables
|
||||
|
||||
A pipeline inside an action may initialize a variable to capture the result.
|
||||
The initialization has syntax
|
||||
|
||||
$variable := pipeline
|
||||
|
||||
where $variable is the name of the variable. An action that declares a
|
||||
variable produces no output.
|
||||
|
||||
If a "range" action initializes a variable, the variable is set to the
|
||||
successive elements of the iteration. Also, a "range" may declare two
|
||||
variables, separated by a comma:
|
||||
|
||||
range $index, $element := pipeline
|
||||
|
||||
in which case $index and $element are set to the successive values of the
|
||||
array/slice index or map key and element, respectively. Note that if there is
|
||||
only one variable, it is assigned the element; this is opposite to the
|
||||
convention in Go range clauses.
|
||||
|
||||
A variable's scope extends to the "end" action of the control structure ("if",
|
||||
"with", or "range") in which it is declared, or to the end of the template if
|
||||
there is no such control structure. A template invocation does not inherit
|
||||
variables from the point of its invocation.
|
||||
|
||||
When execution begins, $ is set to the data argument passed to Execute, that is,
|
||||
to the starting value of dot.
|
||||
|
||||
Examples
|
||||
|
||||
Here are some example one-line templates demonstrating pipelines and variables.
|
||||
All produce the quoted word "output":
|
||||
|
||||
{{"\"output\""}}
|
||||
A string constant.
|
||||
{{`"output"`}}
|
||||
A raw string constant.
|
||||
{{printf "%q" "output"}}
|
||||
A function call.
|
||||
{{"output" | printf "%q"}}
|
||||
A function call whose final argument comes from the previous
|
||||
command.
|
||||
{{printf "%q" (print "out" "put")}}
|
||||
A parenthesized argument.
|
||||
{{"put" | printf "%s%s" "out" | printf "%q"}}
|
||||
A more elaborate call.
|
||||
{{"output" | printf "%s" | printf "%q"}}
|
||||
A longer chain.
|
||||
{{with "output"}}{{printf "%q" .}}{{end}}
|
||||
A with action using dot.
|
||||
{{with $x := "output" | printf "%q"}}{{$x}}{{end}}
|
||||
A with action that creates and uses a variable.
|
||||
{{with $x := "output"}}{{printf "%q" $x}}{{end}}
|
||||
A with action that uses the variable in another action.
|
||||
{{with $x := "output"}}{{$x | printf "%q"}}{{end}}
|
||||
The same, but pipelined.
|
||||
|
||||
Functions
|
||||
|
||||
During execution functions are found in two function maps: first in the
|
||||
template, then in the global function map. By default, no functions are defined
|
||||
in the template but the Funcs method can be used to add them.
|
||||
|
||||
Predefined global functions are named as follows.
|
||||
|
||||
and
|
||||
Returns the boolean AND of its arguments by returning the
|
||||
first empty argument or the last argument, that is,
|
||||
"and x y" behaves as "if x then y else x". All the
|
||||
arguments are evaluated.
|
||||
call
|
||||
Returns the result of calling the first argument, which
|
||||
must be a function, with the remaining arguments as parameters.
|
||||
Thus "call .X.Y 1 2" is, in Go notation, dot.X.Y(1, 2) where
|
||||
Y is a func-valued field, map entry, or the like.
|
||||
The first argument must be the result of an evaluation
|
||||
that yields a value of function type (as distinct from
|
||||
a predefined function such as print). The function must
|
||||
return either one or two result values, the second of which
|
||||
is of type error. If the arguments don't match the function
|
||||
or the returned error value is non-nil, execution stops.
|
||||
html
|
||||
Returns the escaped HTML equivalent of the textual
|
||||
representation of its arguments.
|
||||
index
|
||||
Returns the result of indexing its first argument by the
|
||||
following arguments. Thus "index x 1 2 3" is, in Go syntax,
|
||||
x[1][2][3]. Each indexed item must be a map, slice, or array.
|
||||
js
|
||||
Returns the escaped JavaScript equivalent of the textual
|
||||
representation of its arguments.
|
||||
len
|
||||
Returns the integer length of its argument.
|
||||
not
|
||||
Returns the boolean negation of its single argument.
|
||||
or
|
||||
Returns the boolean OR of its arguments by returning the
|
||||
first non-empty argument or the last argument, that is,
|
||||
"or x y" behaves as "if x then x else y". All the
|
||||
arguments are evaluated.
|
||||
print
|
||||
An alias for fmt.Sprint
|
||||
printf
|
||||
An alias for fmt.Sprintf
|
||||
println
|
||||
An alias for fmt.Sprintln
|
||||
urlquery
|
||||
Returns the escaped value of the textual representation of
|
||||
its arguments in a form suitable for embedding in a URL query.
|
||||
|
||||
The boolean functions take any zero value to be false and a non-zero
|
||||
value to be true.
|
||||
|
||||
There is also a set of binary comparison operators defined as
|
||||
functions:
|
||||
|
||||
eq
|
||||
Returns the boolean truth of arg1 == arg2
|
||||
ne
|
||||
Returns the boolean truth of arg1 != arg2
|
||||
lt
|
||||
Returns the boolean truth of arg1 < arg2
|
||||
le
|
||||
Returns the boolean truth of arg1 <= arg2
|
||||
gt
|
||||
Returns the boolean truth of arg1 > arg2
|
||||
ge
|
||||
Returns the boolean truth of arg1 >= arg2
|
||||
|
||||
For simpler multi-way equality tests, eq (only) accepts two or more
|
||||
arguments and compares the second and subsequent to the first,
|
||||
returning in effect
|
||||
|
||||
arg1==arg2 || arg1==arg3 || arg1==arg4 ...
|
||||
|
||||
(Unlike with || in Go, however, eq is a function call and all the
|
||||
arguments will be evaluated.)
|
||||
|
||||
The comparison functions work on basic types only (or named basic
|
||||
types, such as "type Celsius float32"). They implement the Go rules
|
||||
for comparison of values, except that size and exact type are
|
||||
ignored, so any integer value, signed or unsigned, may be compared
|
||||
with any other integer value. (The arithmetic value is compared,
|
||||
not the bit pattern, so all negative integers are less than all
|
||||
unsigned integers.) However, as usual, one may not compare an int
|
||||
with a float32 and so on.
|
||||
|
||||
Associated templates
|
||||
|
||||
Each template is named by a string specified when it is created. Also, each
|
||||
template is associated with zero or more other templates that it may invoke by
|
||||
name; such associations are transitive and form a name space of templates.
|
||||
|
||||
A template may use a template invocation to instantiate another associated
|
||||
template; see the explanation of the "template" action above. The name must be
|
||||
that of a template associated with the template that contains the invocation.
|
||||
|
||||
Nested template definitions
|
||||
|
||||
When parsing a template, another template may be defined and associated with the
|
||||
template being parsed. Template definitions must appear at the top level of the
|
||||
template, much like global variables in a Go program.
|
||||
|
||||
The syntax of such definitions is to surround each template declaration with a
|
||||
"define" and "end" action.
|
||||
|
||||
The define action names the template being created by providing a string
|
||||
constant. Here is a simple example:
|
||||
|
||||
`{{define "T1"}}ONE{{end}}
|
||||
{{define "T2"}}TWO{{end}}
|
||||
{{define "T3"}}{{template "T1"}} {{template "T2"}}{{end}}
|
||||
{{template "T3"}}`
|
||||
|
||||
This defines two templates, T1 and T2, and a third T3 that invokes the other two
|
||||
when it is executed. Finally it invokes T3. If executed this template will
|
||||
produce the text
|
||||
|
||||
ONE TWO
|
||||
|
||||
By construction, a template may reside in only one association. If it's
|
||||
necessary to have a template addressable from multiple associations, the
|
||||
template definition must be parsed multiple times to create distinct *Template
|
||||
values, or must be copied with the Clone or AddParseTree method.
|
||||
|
||||
Parse may be called multiple times to assemble the various associated templates;
|
||||
see the ParseFiles and ParseGlob functions and methods for simple ways to parse
|
||||
related templates stored in files.
|
||||
|
||||
A template may be executed directly or through ExecuteTemplate, which executes
|
||||
an associated template identified by name. To invoke our example above, we
|
||||
might write,
|
||||
|
||||
err := tmpl.Execute(os.Stdout, "no data needed")
|
||||
if err != nil {
|
||||
log.Fatalf("execution failed: %s", err)
|
||||
}
|
||||
|
||||
or to invoke a particular template explicitly by name,
|
||||
|
||||
err := tmpl.ExecuteTemplate(os.Stdout, "T2", "no data needed")
|
||||
if err != nil {
|
||||
log.Fatalf("execution failed: %s", err)
|
||||
}
|
||||
|
||||
*/
|
||||
package template
|
Reference in New Issue
Block a user