277 lines
8.1 KiB
Go
277 lines
8.1 KiB
Go
package toml
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import (
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"fmt"
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"strings"
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)
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// ParseError is returned when there is an error parsing the TOML syntax.
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//
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// For example invalid syntax, duplicate keys, etc.
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//
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// In addition to the error message itself, you can also print detailed location
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// information with context by using ErrorWithPosition():
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//
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// toml: error: Key 'fruit' was already created and cannot be used as an array.
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//
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// At line 4, column 2-7:
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//
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// 2 | fruit = []
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// 3 |
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// 4 | [[fruit]] # Not allowed
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// ^^^^^
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//
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// Furthermore, the ErrorWithUsage() can be used to print the above with some
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// more detailed usage guidance:
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//
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// toml: error: newlines not allowed within inline tables
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//
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// At line 1, column 18:
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//
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// 1 | x = [{ key = 42 #
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// ^
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//
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// Error help:
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//
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// Inline tables must always be on a single line:
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//
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// table = {key = 42, second = 43}
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//
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// It is invalid to split them over multiple lines like so:
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//
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// # INVALID
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// table = {
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// key = 42,
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// second = 43
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// }
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//
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// Use regular for this:
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//
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// [table]
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// key = 42
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// second = 43
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type ParseError struct {
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Message string // Short technical message.
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Usage string // Longer message with usage guidance; may be blank.
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Position Position // Position of the error
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LastKey string // Last parsed key, may be blank.
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Line int // Line the error occurred. Deprecated: use Position.
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err error
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input string
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}
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// Position of an error.
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type Position struct {
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Line int // Line number, starting at 1.
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Start int // Start of error, as byte offset starting at 0.
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Len int // Lenght in bytes.
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}
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func (pe ParseError) Error() string {
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msg := pe.Message
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if msg == "" { // Error from errorf()
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msg = pe.err.Error()
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}
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if pe.LastKey == "" {
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return fmt.Sprintf("toml: line %d: %s", pe.Position.Line, msg)
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}
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return fmt.Sprintf("toml: line %d (last key %q): %s",
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pe.Position.Line, pe.LastKey, msg)
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}
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// ErrorWithUsage() returns the error with detailed location context.
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//
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// See the documentation on ParseError.
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func (pe ParseError) ErrorWithPosition() string {
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if pe.input == "" { // Should never happen, but just in case.
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return pe.Error()
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}
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var (
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lines = strings.Split(pe.input, "\n")
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col = pe.column(lines)
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b = new(strings.Builder)
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)
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msg := pe.Message
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if msg == "" {
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msg = pe.err.Error()
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}
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// TODO: don't show control characters as literals? This may not show up
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// well everywhere.
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if pe.Position.Len == 1 {
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fmt.Fprintf(b, "toml: error: %s\n\nAt line %d, column %d:\n\n",
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msg, pe.Position.Line, col+1)
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} else {
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fmt.Fprintf(b, "toml: error: %s\n\nAt line %d, column %d-%d:\n\n",
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msg, pe.Position.Line, col, col+pe.Position.Len)
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}
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if pe.Position.Line > 2 {
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fmt.Fprintf(b, "% 7d | %s\n", pe.Position.Line-2, lines[pe.Position.Line-3])
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}
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if pe.Position.Line > 1 {
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fmt.Fprintf(b, "% 7d | %s\n", pe.Position.Line-1, lines[pe.Position.Line-2])
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}
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fmt.Fprintf(b, "% 7d | %s\n", pe.Position.Line, lines[pe.Position.Line-1])
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fmt.Fprintf(b, "% 10s%s%s\n", "", strings.Repeat(" ", col), strings.Repeat("^", pe.Position.Len))
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return b.String()
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}
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// ErrorWithUsage() returns the error with detailed location context and usage
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// guidance.
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//
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// See the documentation on ParseError.
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func (pe ParseError) ErrorWithUsage() string {
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m := pe.ErrorWithPosition()
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if u, ok := pe.err.(interface{ Usage() string }); ok && u.Usage() != "" {
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lines := strings.Split(strings.TrimSpace(u.Usage()), "\n")
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for i := range lines {
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if lines[i] != "" {
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lines[i] = " " + lines[i]
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}
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}
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return m + "Error help:\n\n" + strings.Join(lines, "\n") + "\n"
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}
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return m
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}
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func (pe ParseError) column(lines []string) int {
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var pos, col int
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for i := range lines {
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ll := len(lines[i]) + 1 // +1 for the removed newline
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if pos+ll >= pe.Position.Start {
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col = pe.Position.Start - pos
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if col < 0 { // Should never happen, but just in case.
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col = 0
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}
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break
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}
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pos += ll
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}
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return col
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}
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type (
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errLexControl struct{ r rune }
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errLexEscape struct{ r rune }
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errLexUTF8 struct{ b byte }
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errLexInvalidNum struct{ v string }
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errLexInvalidDate struct{ v string }
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errLexInlineTableNL struct{}
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errLexStringNL struct{}
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errParseRange struct {
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i interface{} // int or float
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size string // "int64", "uint16", etc.
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}
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errParseDuration struct{ d string }
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)
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func (e errLexControl) Error() string {
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return fmt.Sprintf("TOML files cannot contain control characters: '0x%02x'", e.r)
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}
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func (e errLexControl) Usage() string { return "" }
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func (e errLexEscape) Error() string { return fmt.Sprintf(`invalid escape in string '\%c'`, e.r) }
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func (e errLexEscape) Usage() string { return usageEscape }
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func (e errLexUTF8) Error() string { return fmt.Sprintf("invalid UTF-8 byte: 0x%02x", e.b) }
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func (e errLexUTF8) Usage() string { return "" }
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func (e errLexInvalidNum) Error() string { return fmt.Sprintf("invalid number: %q", e.v) }
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func (e errLexInvalidNum) Usage() string { return "" }
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func (e errLexInvalidDate) Error() string { return fmt.Sprintf("invalid date: %q", e.v) }
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func (e errLexInvalidDate) Usage() string { return "" }
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func (e errLexInlineTableNL) Error() string { return "newlines not allowed within inline tables" }
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func (e errLexInlineTableNL) Usage() string { return usageInlineNewline }
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func (e errLexStringNL) Error() string { return "strings cannot contain newlines" }
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func (e errLexStringNL) Usage() string { return usageStringNewline }
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func (e errParseRange) Error() string { return fmt.Sprintf("%v is out of range for %s", e.i, e.size) }
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func (e errParseRange) Usage() string { return usageIntOverflow }
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func (e errParseDuration) Error() string { return fmt.Sprintf("invalid duration: %q", e.d) }
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func (e errParseDuration) Usage() string { return usageDuration }
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const usageEscape = `
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A '\' inside a "-delimited string is interpreted as an escape character.
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The following escape sequences are supported:
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\b, \t, \n, \f, \r, \", \\, \uXXXX, and \UXXXXXXXX
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To prevent a '\' from being recognized as an escape character, use either:
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- a ' or '''-delimited string; escape characters aren't processed in them; or
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- write two backslashes to get a single backslash: '\\'.
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If you're trying to add a Windows path (e.g. "C:\Users\martin") then using '/'
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instead of '\' will usually also work: "C:/Users/martin".
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`
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const usageInlineNewline = `
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Inline tables must always be on a single line:
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table = {key = 42, second = 43}
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It is invalid to split them over multiple lines like so:
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# INVALID
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table = {
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key = 42,
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second = 43
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}
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Use regular for this:
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[table]
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key = 42
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second = 43
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`
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const usageStringNewline = `
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Strings must always be on a single line, and cannot span more than one line:
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# INVALID
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string = "Hello,
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world!"
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Instead use """ or ''' to split strings over multiple lines:
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string = """Hello,
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world!"""
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`
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const usageIntOverflow = `
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This number is too large; this may be an error in the TOML, but it can also be a
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bug in the program that uses too small of an integer.
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The maximum and minimum values are:
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size │ lowest │ highest
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───────┼────────────────┼──────────
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int8 │ -128 │ 127
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int16 │ -32,768 │ 32,767
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int32 │ -2,147,483,648 │ 2,147,483,647
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int64 │ -9.2 × 10¹⁷ │ 9.2 × 10¹⁷
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uint8 │ 0 │ 255
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uint16 │ 0 │ 65535
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uint32 │ 0 │ 4294967295
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uint64 │ 0 │ 1.8 × 10¹⁸
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int refers to int32 on 32-bit systems and int64 on 64-bit systems.
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`
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const usageDuration = `
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A duration must be as "number<unit>", without any spaces. Valid units are:
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ns nanoseconds (billionth of a second)
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us, µs microseconds (millionth of a second)
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ms milliseconds (thousands of a second)
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s seconds
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m minutes
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h hours
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You can combine multiple units; for example "5m10s" for 5 minutes and 10
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seconds.
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`
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