Files
mgmt/lang/parser/lexer.nex
James Shubin 045b29291e engine, lang: Modern exported resources
I've been waiting to write this patch for a long time. I firmly believe
that the idea of "exported resources" was truly a brilliant one, but
which was never even properly understood by its original inventors! This
patch set aims to show how it should have been done.

The main differences are:

* Real-time modelling, since "once per run" makes no sense.
* Filter with code/functions not language syntax.
* Directed exporting to limit the intended recipients.

The next step is to add more "World" reading and filtering functions to
make it easy and expressive to make your selection of resources to
collect!
2025-04-05 12:45:23 -04:00

416 lines
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/[ \t\n]/ { /* skip over whitespace */ }
/{/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return OPEN_CURLY
}
/}/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return CLOSE_CURLY
}
/\(/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return OPEN_PAREN
}
/\)/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return CLOSE_PAREN
}
/\[/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return OPEN_BRACK
}
/\]/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return CLOSE_BRACK
}
/if/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return IF
}
/else/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return ELSE
}
/\?:/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return ELVIS
}
/\|\|/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return DEFAULT
}
/=>/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return ROCKET
}
/,/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return COMMA
}
/:/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
// sanity check... these should be the same!
if x, y := lval.str, interfaces.ClassSep; x != y {
panic(fmt.Sprintf("COLON does not match ClassSep (%s != %s)", x, y))
}
return COLON
}
/;/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return SEMICOLON
}
/=/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return EQUALS
}
/\+/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return PLUS
}
/\-/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return MINUS
}
/\*/ {
// This is used as the multiplication symbol, but also
// (for now) the bare import feature, eg: `import as *`.
yylex.pos(lval) // our pos
lval.str = yylex.Text()
// sanity check... these should be the same!
if x, y := lval.str, interfaces.BareSymbol; x != y {
panic(fmt.Sprintf("MULTIPLY does not match BareSymbol (%s != %s)", x, y))
}
return MULTIPLY
}
/\// {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return DIVIDE
}
/==/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return EQ
}
/!=/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return NEQ
}
/</ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return LT
}
/>/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return GT
}
/<=/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return LTE
}
/>=/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return GTE
}
/and/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return AND
}
/or/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return OR
}
/not/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return NOT
}
/in/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return IN
}
/for/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return FOR
}
/forkv/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return FORKV
}
/\->/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return ARROW
}
/\./ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
// sanity check... these should be the same!
if x, y := lval.str, interfaces.ModuleSep; x != y {
panic(fmt.Sprintf("DOT does not match ModuleSep (%s != %s)", x, y))
}
return DOT
}
/\$/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return DOLLAR
}
/bool/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return BOOL_IDENTIFIER
}
/str/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return STR_IDENTIFIER
}
/int/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return INT_IDENTIFIER
}
/float/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return FLOAT_IDENTIFIER
}
/map/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return MAP_IDENTIFIER
}
/struct/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return STRUCT_IDENTIFIER
}
/func/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return FUNC_IDENTIFIER
}
/class/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return CLASS_IDENTIFIER
}
/include/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return INCLUDE_IDENTIFIER
}
/import/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return IMPORT_IDENTIFIER
}
/as/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return AS_IDENTIFIER
}
/variant/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return VARIANT_IDENTIFIER
}
/true|false/ {
yylex.pos(lval) // our pos
s := yylex.Text()
if s == "true" {
lval.bool = true
} else if s == "false" {
lval.bool = false
} else {
// the lexer was wrong
panic(fmt.Sprintf("error lexing BOOL, got: %s", s))
}
return BOOL
}
/panic/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return PANIC_IDENTIFIER
}
/collect/ {
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return COLLECT_IDENTIFIER
}
/"(\\.|[^"])*"/
{ // This matches any number of the bracketed patterns
// that are surrounded by the two quotes on each side.
// The bracket pattern is any escaped char or something
// that is not a single quote char. See this reference:
// https://www.lysator.liu.se/c/ANSI-C-grammar-l.html#STRING-LITERAL
// old: /"[\a\b\t\n\v\f\r !#$%&'()*+,-.\/0-9:;<=>?@A-Z\[\\\]^_a-z{|}~]*"/
yylex.pos(lval) // our pos
s := yylex.Text()
if s[0:1] != "\"" || s[len(s)-1:] != "\"" {
// unhandled error
panic(fmt.Sprintf("error lexing STRING, got: %s", s))
//return ERROR // unreachable
}
lval.str = s[1:len(s)-1] // remove the two quotes
return STRING
}
/\-?[0-9]+/
{
yylex.pos(lval) // our pos
s := yylex.Text()
var err error
lval.int, err = strconv.ParseInt(s, 10, 64) // int64
if err == nil {
return INTEGER
} else if e := err.(*strconv.NumError); e.Err == strconv.ErrRange {
// this catches range errors for very large ints
lp := yylex.cast()
lp.lexerErr = &LexParseErr{
Err: ErrLexerIntegerOverflow,
Str: s,
Row: yylex.Line(),
Col: yylex.Column(),
}
return ERROR
} else {
panic(fmt.Sprintf("error lexing INTEGER, got: %v", err))
}
}
/\-?[0-9]+\.[0-9]+/
{
yylex.pos(lval) // our pos
s := yylex.Text()
var err error
lval.float, err = strconv.ParseFloat(s, 64) // float64
if err == nil {
return FLOAT
} else if e := err.(*strconv.NumError); e.Err == strconv.ErrRange {
// this catches range errors for very large floats
lp := yylex.cast()
lp.lexerErr = &LexParseErr{
Err: ErrLexerFloatOverflow,
Str: s,
Row: yylex.Line(),
Col: yylex.Column(),
}
return ERROR
} else {
panic(fmt.Sprintf("error lexing FLOAT, got: %v", err))
}
}
/[a-z]([a-z0-9_]*[a-z0-9]+)?/
{
yylex.pos(lval) // our pos
lval.str = yylex.Text()
return IDENTIFIER
}
/[A-Z]([a-z0-9_]*[a-z0-9]+)?/
{
yylex.pos(lval) // our pos
s := yylex.Text()
lval.str = strings.ToLower(s) // uncapitalize it
return CAPITALIZED_IDENTIFIER
}
/#[^\n]*/
{ // this matches a (#) pound char followed by any
// number of chars that aren't the (\n) newline!
yylex.pos(lval) // our pos
s := yylex.Text()
lval.str = s[1:] // remove the leading #
//log.Printf("lang: lexer: comment: `%s`", lval.str)
//return COMMENT // skip return to avoid parsing
}
/./ {
yylex.pos(lval) // our pos
s := yylex.Text()
lp := yylex.cast()
e := ErrLexerUnrecognized
if s == "\r" { // windows!
e = ErrLexerUnrecognizedCR
}
lp.lexerErr = &LexParseErr{
Err: e,
Str: s,
Row: yylex.Line(),
Col: yylex.Column(),
}
return ERROR
}
//
// Mgmt
// Copyright (C) James Shubin and the project contributors
// Written by James Shubin <james@shubin.ca> and the project contributors
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
//
// Additional permission under GNU GPL version 3 section 7
//
// If you modify this program, or any covered work, by linking or combining it
// with embedded mcl code and modules (and that the embedded mcl code and
// modules which link with this program, contain a copy of their source code in
// the authoritative form) containing parts covered by the terms of any other
// license, the licensors of this program grant you additional permission to
// convey the resulting work. Furthermore, the licensors of this program grant
// the original author, James Shubin, additional permission to update this
// additional permission if he deems it necessary to achieve the goals of this
// additional permission.
package parser
import (
"fmt"
"strconv"
"github.com/purpleidea/mgmt/lang/interfaces"
)
// NOTE:
// Among rules in the same scope, the longest matching pattern takes precedence.
// In event of a tie, the first pattern wins.