std/strtabs (original) (raw)

Source Edit

The strtabs module implements an efficient hash table that is a mapping from strings to strings. Supports a case-sensitive, case-insensitive and style-insensitive mode.

Example:

import std/strtabs var t = newStringTable() t["name"] = "John" t["city"] = "Monaco" doAssert t.len == 2 doAssert t.hasKey "name" doAssert "name" in t

String tables can be created from a table constructor:

Example:

import std/strtabs var t = {"name": "John", "city": "Monaco"}.newStringTable

When using the style insensitive mode (

modeStyleInsensitive

), all letters are compared case insensitively within the ASCII range and underscores are ignored.

Example:

import std/strtabs var x = newStringTable(modeStyleInsensitive) x["first_name"] = "John" x["LastName"] = "Doe"

doAssert x["firstName"] == "John" doAssert x["last_name"] == "Doe"

An efficient string substitution operator % for the string table is also provided.

Example:

import std/strtabs var t = {"name": "John", "city": "Monaco"}.newStringTable doAssert "${name} lives in ${city}" % t == "John lives in Monaco"

See also:

Types

StringTableMode = enum modeCaseSensitive,
modeCaseInsensitive,
modeStyleInsensitive

Describes the tables operation mode.Source Edit

Procs

proc $(t: StringTableRef): string {....gcsafe, extern: "nstDollar", raises: [], tags: [], forbids: [].}

The $ operator for string tables. Used internally when calling echo on a table.Source Edit

proc %(f: string; t: StringTableRef; flags: set[FormatFlag] = {}): string {. ...gcsafe, extern: "nstFormat", raises: [ValueError], tags: [ReadEnvEffect], forbids: [].}

The % operator for string tables.

Example:

var t = {"name": "John", "city": "Monaco"}.newStringTable doAssert "${name} lives in ${city}" % t == "John lives in Monaco"

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proc [](t: StringTableRef; key: string): var string {....gcsafe, extern: "nstTake", raises: [KeyError], tags: [], forbids: [].}

Retrieves the location at t[key].

If key is not in t, the KeyError exception is raised. One can check with hasKey proc whether the key exists.

See also:

Example:

var t = {"name": "John", "city": "Monaco"}.newStringTable doAssert t["name"] == "John" doAssertRaises(KeyError): echo t["occupation"]

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proc []=(t: StringTableRef; key, val: string) {....gcsafe, extern: "nstPut", raises: [], tags: [], forbids: [].}

Inserts a (key, value) pair into t.

See also:

Example:

var t = {"name": "John", "city": "Monaco"}.newStringTable t["occupation"] = "teacher" doAssert t.hasKey("occupation")

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proc clear(s: StringTableRef) {....raises: [], tags: [], forbids: [].}

Resets a string table to be empty again without changing the mode.Source Edit

proc clear(s: StringTableRef; mode: StringTableMode) {....gcsafe, extern: "nst$1", raises: [], tags: [], forbids: [].}

Resets a string table to be empty again, perhaps altering the mode.

See also:

Example:

var t = {"name": "John", "city": "Monaco"}.newStringTable clear(t, modeCaseSensitive) doAssert len(t) == 0 doAssert "name" notin t doAssert "city" notin t

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proc contains(t: StringTableRef; key: string): bool {....raises: [], tags: [], forbids: [].}

Alias of hasKey proc for use with the in operator.

Example:

var t = {"name": "John", "city": "Monaco"}.newStringTable doAssert "name" in t doAssert "occupation" notin t

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proc del(t: StringTableRef; key: string) {....raises: [], tags: [], forbids: [].}

Removes key from t.

See also:

Example:

var t = {"name": "John", "city": "Monaco"}.newStringTable t.del("name") doAssert len(t) == 1 doAssert "name" notin t doAssert "city" in t

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proc getOrDefault(t: StringTableRef; key: string; default: string = ""): string {. ...raises: [], tags: [], forbids: [].}

Retrieves the location at t[key].

If key is not in t, the default value is returned (if not specified, it is an empty string ("")).

See also:

Example:

var t = {"name": "John", "city": "Monaco"}.newStringTable doAssert t.getOrDefault("name") == "John" doAssert t.getOrDefault("occupation") == "" doAssert t.getOrDefault("occupation", "teacher") == "teacher" doAssert t.getOrDefault("name", "Paul") == "John"

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proc hasKey(t: StringTableRef; key: string): bool {....gcsafe, extern: "nst$1", raises: [], tags: [], forbids: [].}

Returns true if key is in the table t.

See also:

Example:

var t = {"name": "John", "city": "Monaco"}.newStringTable doAssert t.hasKey("name") doAssert not t.hasKey("occupation")

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proc len(t: StringTableRef): int {....gcsafe, extern: "nst$1", raises: [], tags: [], forbids: [].}

Returns the number of keys in t.Source Edit

proc newStringTable(keyValuePairs: varargs[string]; mode: StringTableMode): owned( StringTableRef) {....gcsafe, extern: "nst$1WithPairs", noSideEffect, ...raises: [], tags: [], forbids: [].}

Creates a new string table with given key, value string pairs.

StringTableMode must be specified.

Example:

var mytab = newStringTable("key1", "val1", "key2", "val2", modeCaseInsensitive)

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proc newStringTable(keyValuePairs: varargs[tuple[key, val: string]]; mode: StringTableMode = modeCaseSensitive): owned( StringTableRef) {....gcsafe, extern: "nst$1WithTableConstr", noSideEffect, ...raises: [], tags: [], forbids: [].}

Creates a new string table with given (key, value) tuple pairs.

The default mode is case sensitive.

Example:

var mytab1 = newStringTable({"key1": "val1", "key2": "val2"}, modeCaseInsensitive) mytab2 = newStringTable([("key3", "val3"), ("key4", "val4")])

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proc newStringTable(mode: StringTableMode): owned(StringTableRef) {....gcsafe, extern: "nst$1", noSideEffect, ...raises: [], tags: [], forbids: [].}

Creates a new empty string table.

See also:

Iterators

iterator pairs(t: StringTableRef): tuple[key, value: string] {....raises: [], tags: [], forbids: [].}

Iterates over every (key, value) pair in the table t.Source Edit