@{%
import lexer from './grammar/lexer.js'
import * as p from './grammar/parse.js'
%}

@preprocessor typescript
@lexer lexer

# structure
program -> _ (inputs line_sep):? statements _ {% p.program %}
statements -> statement (line_sep statement):* {% p.statements %}
statement -> (request | assignment | extract) {% p.idd %}

# keywords
inputs -> "inputs" __ "{" _ input_decl (_ "," _ input_decl):* _ "}" {% p.declInputs %}
assignment -> "set" __ %identifier "?":? _ "=" _ expression {% p.assignment %}
extract -> "extract" __ expression {% p.extract %}

# inputs
input_decl -> %identifier "?":? (_ "=" _ input_default):? {% p.inputDecl %}
input_default -> slice {% id %}

# request
request -> %request_verb template (line_sep request_block):? request_blocks {% p.request %}
request_blocks -> (line_sep request_block_named):* (line_sep request_block_body):? {% p.requestBlocks %}
request_block_named -> %request_block_name line_sep request_block {% p.requestBlockNamed %}
request_block -> request_entry (line_sep request_entry):* {% p.requestBlock %}
request_entry -> template ":" (__ template):? {% p.requestEntry %}
request_block_body -> %request_block_body template %request_block_body_end {% p.requestBlockBody %}

# expression
expression -> drill {% id %}
expression -> (drill _ %drill_arrow _):? %link _ drill {% p.link %}

# drill
drill -> (%drill_arrow _):? bit (_ %drill_arrow _ bit):* {% p.drill %}

# drill bit
bit -> (literal | slice | call | object | subquery) {% p.idd %}
bit -> template {% p.selector %}
bit -> %identifier_expr {% p.idbit %}

# subqueries
subquery -> "(" _ statements _ ")" {% p.subquery %}

# calls
call -> %call ("(" object ")"):? {% p.call %}

# object literals
object -> "{" _ (object_entry (_ ","):? _):* "}" {% p.object %}
object_entry -> "@":? %identifier "?":? ":" _ expression {% p.objectEntry %}
object_entry -> %identifier "?":? {% p.objectEntryShorthandSelect %}
object_entry -> %identifier_expr "?":? {% p.objectEntryShorthandIdent %}

# templates
template -> (%str | %interpvar | interp_expr | interp_tmpl):+ {% p.template %}
interp_expr -> "${" _ %identifier _ "}" {% p.interpExpr %}
interp_tmpl -> "$[" _ template _ "]" {% p.interpTmpl %}

# literals
literal -> (%bool | %num) {% p.literal %}
literal -> "'" template "'" {% p.string %}
literal -> "\"" template "\"" {% p.string %}
slice -> %slice {% p.slice %}

# whitespace
line_sep -> (%ws | %comment):* %nl _ {% p.ws %}
__ -> ws:+ {% p.ws %}
_ -> ws:* {% p.ws %}
ws -> (%ws | %comment | %nl) {% p.ws %}