terraform/config/lang/lang.y

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2015-01-11 21:38:45 +01:00
// This is the yacc input for creating the parser for interpolation
// expressions in Go. To build it, just run `go generate` on this
// package, as the lexer has the go generate pragma within it.
%{
package lang
import (
"github.com/hashicorp/terraform/config/lang/ast"
)
%}
%union {
node ast.Node
str string
}
%token <str> STRING IDENTIFIER PROGRAM_BRACKET_LEFT PROGRAM_BRACKET_RIGHT
%type <node> expr interpolation literal
%%
top:
literal
{
parserResult = $1
}
| literal interpolation
{
parserResult = &ast.Concat{
Exprs: []ast.Node{$1, $2},
}
}
interpolation:
PROGRAM_BRACKET_LEFT expr PROGRAM_BRACKET_RIGHT
{
$$ = $2
}
expr:
IDENTIFIER
{
$$ = &ast.VariableAccess{Name: $1}
}
| literal
{
$$ = $1
}
literal:
STRING
{
$$ = &ast.LiteralNode{Value: $1, Type: ast.TypeString}
}
%%